DOI: https://dx.doi.org/10.22201/igc.20072902e.2026.1.1924

Geochronology and geochemistry of the Paleogene Magdalena Suite of anatectic granites in northern Sonora, México

James B. Chapman1,*,a, Carlos M. González-León2, b, Luigi A. Solari3, c, Elizard González-Becuar4, d, Jonathan A. Nourse5, e, Michelle Vázquez6, Teresita Sánchez Navarro2, Rufino Lozano Santacruz7, f, Ofelia Pérez Arvizu3, and Estefany G. Grijalva Espinoza8

1 Department of Earth, Environmental and Resource Sciences, University of Texas at El Paso, El Paso, Texas 79968, U.S.A.

2 Estación Regional del Noroeste, Instituto de Geología, Universidad Nacional Autónoma de México, Hermosillo, Sonora 83000, Mexico.

3 Instituto de Geociencias, Universidad Nacional Autónoma de México, Juriquilla, Querétaro 76230, Mexico.

4 Laboratorio Nacional de Geoquímica y Mineralogía, Estación Regional del Noroeste, Instituto de Geología, Universidad Nacional Autónoma de México, Hermosillo, Sonora 83000, Mexico.

5 Department of Geological Sciences, Cal Poly Pomona, Pomona, California 91768, U.S.A.

6 Universidad Estatal de Sonora, Ingeniería en Geociencias, Hermosillo, Sonora 83100, Mexico.

7 Universidad Nacional Autónoma de México, Instituto de Geología, Laboratorio Nacional de Geoquímica y Mineralogía, Ciudad Universitaria, Ciudad de México, 04510, Mexico.

8 Universidad Estatal de Sonora, Unidad Académica Magdalena, Ingeniería en Geociencias, Magdalena de Kino, Sonora 84160, Mexico.

*Corrresponding author (J. B. Chapman): jbchapmanv@utep.edu

a 0000-0002-1145-4687; b 0000-0002-4982-8015; c 0000-0002-9769-6846; d 0009-0009-2332-5901; e 0000-0002-7566-7542, f 0000-0002-6341-8039

 

ABSTRACT

New zircon U-Pb geochronology, zircon geochemistry, and whole rock geochemistry are presented from the Magdalena granites in northern Sonora, Mexico that outcrop in the footwall of the Magdalena-Madera metamorphic core complex. Crystallization ages of the Magdalena granites are predominantly Eocene (51 to 38 Ma; n = 21) with two Paleocene ages (60 and 59 Ma). These ages are generally younger than subduction-related magmatism associated with the Cretaceous Eocene Mexican Magmatic Arc (CEMMA) in the northern Mexican Cordillera, including new ages (72 to 61 Ma; n = 8) from this study. The Magdalena granites are also mineralogically, compositionally, and texturally distinct from CEMMA rocks. The granites are moderately peraluminous, two-mica + garnet leucogranite (> 70 wt. % SiO2), relatively depleted in LREE and enriched in HREE, and have major and trace element chemistry consistent with water-absent, muscovite- to biotite-dehydration melting of metasedimentary to metaigneous protoliths. Zircon from the Magdalena granites have high U/Th ratios (median = 11.5) compared to CEMMA zircon (U/Th < 5) and are relatively enriched in HREE compared to CEMMA zircon. The results of this study suggest that the Magdalena granites are anatectic in origin and are part of the North American Cordilleran Anatectic Belt. The Magdalena granites crystallized from evolved melts that underwent early feldspar crystallization and were separated from a feldspar-rich residue, presumably a migmatitic source deeper in the crust. Field and petrographic relationships suggest the Magdalena granites intruded into relatively hot crust, including host rock mushes that exhibit evidence for melt infiltration and disaggregation.

Keywords: crustal melting; Laramide; Mexican orogen; leucogranite; Cordillera; Mexico.

RESUMEN

Se presentan nuevos datos de geocronología U-Pb en zircones, así como de geoquímica en zircones y roca total de los granitos de Magdalena, en el norte de Sonora, México. Estas rocas se encuentran en el bloque de piso del complejo de núcleo metamórfico Magdalena-Madera. Las edades de cristalización de los granitos de Magdalena son predominantemente del Eoceno (51 a 38 Ma; n=21), con dos en el Paleoceno (60 y 59 Ma). Estas edades son generalmente más jóvenes que el magmatismo de subducción asociado al Arco Magmático del Cretácico-Eoceno (CEMMA) en la Cordillera Mexicana norte, incluyendo nuevas edades (72 a 61 Ma; n = 8) de este estudio. Los granitos de Magdalena también son mineralógicamente, composicionalmente, y texturalmente distintos a las rocas del CEMMA. Los granitos son moderadamente peraluminosos, leucogranito (> 70 wt. % SiO2) de dos-micas + granate, relativamente empobrecidos en LREE y enriquecidos en HREE, y tienen una química de elementos mayores y traza consistente con la fusión por deshidratación de moscovita - biotita de protolitos metasedimentarios en condiciones anhidras. Los zircones de los granitos de Magdalena presentan altas relaciones U/Th (media = 11.5) en comparación con los del CEMMA (U/Th < 5) y están relativamente más enriquecidos en HREE que el zircón del CEMMA. Los resultados de este estudio sugieren que los granitos de Magdalena son de origen anatéctico y forman parte del Cinturón Anatéctico Cordillerano de América del Norte. Los granitos de Magdalena cristalizaron a partir de fundidos evolucionados que presentaron una cristalización temprana de feldespato y se separaron de un residuo rico en feldespato, presumiblemente procedente de una fuente migmatítica más profunda en la corteza. Las relaciones de campo y petrográficas sugieren que los granitos de Magdalena se introdujeron en una corteza relativamente caliente, incluidas masas de roca anfitriona que muestran evidencia de infiltración y desagregación de material fundido.

Palabras clave: fusión de la corteza; Laramide; Orógeno Mexicano; leucogranito; Cordillera; México.

 

 

INTRODUCTION

One of the fundamental components of the North American Cordillera is a long-lived magmatic arc related to the eastward-directed subduction of the oceanic lithosphere during Mesozoic to Paleogene time (Dickinson, 2004). Some of the most well-known examples of this magmatism are the large coastal Cordilleran batholiths, including the Peninsular Ranges Batholith in the southwest U.S. and northwest México. In this region, arc magmatism was not restricted to the coastal batholith and began to migrate inland, away from the trench, during the mid-Cretaceous (Silver and Chappell, 1988; Dickinson and Lawton, 2001; Kimbrough et al., 2015; Contreras-López et al., 2021; Chapman et al. 2025). The result of this migration is a broad, ~1000 km wide belt of discontinuously exposed, Late Cretaceous to Eocene magmatic rocks, commonly referred to as the Laramide arc (Coney, 1972; Coney and Reynolds, 1977; Clark et al., 1982; Damon et al., 1983a, 1983b; McDowell et al., 2001), although the part of the belt located in México has recently been renamed the Cretaceous Eocene Mexican magmatic arc (CEMMA) by Valencia-Moreno et al. (2021). In central to northern Sonora, México, the age of arc magmatism is generally constrained to be 90–50 Ma (Roldán-Quintana et al., 2009; McDowell et al., 2001; González-León et al., 2017; Valencia-Moreno et al., 2021) and intrusive rocks with published dates younger than 50 Ma are scarce (Roldán-Quintana et al., 2009; González-Becuar et al., 2017; González-León and Moreno-Hurtado, 2021).

The North American Cordilleran Anatectic Belt contains magmatic rocks overlapping spatially and in age with CEMMA. However, these rocks were produced primarily by crustal anatexis, rather than subduction-related processes (Miller and Bradfish, 1980; Miller and Barton, 1990; Lee et al., 1981; Farmer and DePaolo, 1983; Haxel et al., 1984; Patiño-Douce et al., 1990; Wright and Wooden, 1991; Chapman et al., 2021, 2023). These rocks are compositionally and petrologically distinct from arc-related magmatism in the Cordillera (Chapman et al., 2021; Haxel et al., 2022).

Previous studies have suggested that Paleogene age intrusive rocks related to crustal melting are present in Sonora (González-Becuar et al., 2017; Nourse et al., 2018) and Chapman et al. (2021) suggested they are part of the North American Cordilleran Anatectic Belt and attributed their formation to crustal melting in a region of tectonically thickened crust in southern Arizona, U.S.A. and northern Sonora – the “Arizonaplano” (Chapman et al. 2019). However, some of these rocks could also be part of CEMMA and related to arc magmatism (Valencia-Moreno et al., 2021). Part of the difficulty in assessing the validity of extending the North American Cordilleran Anatectic Belt into Sonora is that very little geochronologic and geochemical data are available for these rocks.

 

GEOLOGIC BACKGROUND

The study area in north-central Sonora (Figure 1) has been reported to be part of the 1.6 to 1.7 Ga, cratonic Mazatzal basement province (Whitmeyer and Karlstrom, 2007), although basement rock exposures are scarce. A small outcrop of the El Salto augen gneiss (same location as samples 304 and 305; Figure 1) occurs as a large xenolith within a Paleogene-age granite in the southern Sierra Magdalena and is the only known basement exposure in the study area. Samples collected from the El Salto augen gneiss outcrop yielded zircon 206Pb/238U ages of 1037 Ma (Nourse et al., 2018) and 1072 Ma, with a large population of inherited dates at ca. 1392 Ma (González-León et al., 2021). Permo-Triassic intrusive arc rocks with ages of ca. 284–224 Ma have been documented in northwestern Sonora (Barth and Wooden, 2006; Barth et al., 1990; 1997; Iriondo et al., 2022), but do not outcrop in the study area. Apart from the Paleogene granites investigated in this study, most of the outcrops in the study area are Jurassic igneous, metasedimentary, and metaigneous rocks associated with the Mesozoic continental arc system and intra-arc extensional deformation (Busby-Spera, 1988; Anderson et al., 2005; Haxel et al., 2008; González-León et al., 2021; Busby and Centeno-García, 2022). Zircon U-Pb ages on Jurassic rocks from the study area range from 158 to 176 Ma (González-León et al., 2021). Starting in Late Jurassic time, Sonora was affected by back-arc rift extension associated with the opening of the Gulf of México and rollback of the subducted Farallon plate in southwestern North America (Dickinson and Lawton, 2001), resulting in sediment accumulation in the Bisbee basin, which continued through Early Cretaceous time in the study area (Dickinson and Lawton, 2001; Peryam et al., 2012; González-León et al., 2020; Lawton et al., 2020). Several intrusive igneous rocks in the study area were presumed to be Late Cretaceous to earliest Paleogene in age and related to CEMMA based on their mineralogy, textures, and field relations to Jurassic and Cretaceous host rocks (cf. González-León et al., 2021). However, relatively few dates are available.

 

 

The present study focuses on the leucocratic Magdalena granites in north-central Sonora. A few Eocene zircon U-Pb ages from these granites have been reported in conference abstracts (Herrera-Urbina et al., 2006; Nourse et al., 2018), however, the petrography, geochemistry, and age of these granites have not been fully characterized and remain uncertain. Besides the Magdalena granites, Paleogene age leucogranites and two-mica granites in Sonora that may be part of the North American Cordilleran Anatectic Belt include rocks in the footwall of the Mezquital, Pozo Verde, Mazatán, Puerta del Sol, and Aconchi metamorphic core complexes (Anderson et al., 1980; Roldán-Quintana, 2009; Nourse et al., 1994, 1995; González-León et al., 2011; González-Becuar et al., 2017; Chapman et al., 2021). Many of these rocks were included within the larger CEMMA database (Valencia-Moreno et al., 2021) but could be distinct from older arc magmatism in the region.

The study area was first recognized as part of a metamorphic core complex by Davis et al. (1981) and the structure was studied in detail by Nourse (1989). Nourse (1989) recognized that the footwall of the Magdalena-Madera-Tubutama metamorphic core complex was composed of sheared, Jurassic and Cretaceous igneous and sedimentary rocks that were then intruded by at least two generations of Late Cretaceous-Tertiary age granites. 40Ar/39Ar thermochronologic dates from mylonitized granites and pegmatites in the footwall of the Magdalena-Madera core complex indicate that extension and rapid exhumation occurred from 25 to 22 Ma (Wong et al., 2010). Nourse (1989; 1990) produced the first detailed geologic map for Sierra Guacomea, Sierra La Jojoba, and Sierra Magdalena (Figure 1). The Servicio Geológico Mexicano subsequently published several additional geologic maps (1:50000 scale) from the study area including for the Imuris (Ramírez López et al., 2018), El Carrizo (Moreno Ibarra and Martínez Cuevas, 2019), Santa Ana (Compañía Minera Cascabel, 2000) and El Correo areas (Escamilla Torres and Guzmán Espinoza, 2008).

 

SAMPLE DESCRIPTIONS AND FIELD RELATIONSHIPS

We investigated several two-mica granites and leucogranites with mylonitic fabrics first recognized by Nourse (1989) in the study area (Figure 1; Table 1). We divide the Magdalena granites into three groups based on their geographic location. The Magdalena group occurs in the mountains north and east of the town of Magdalena and includes the Cañada Tescalama, La Mariana, Sierra Magdalena, Terrenate, Rancho La Esperanza, San Ignacio, La Piocha, and Sierra Madera granites. The Yegua group occurs west of the town of Magdalena in the Sierra El Potrero – Sierra La Yegua- and Sierra Las Jarillas and includes the La Yegua and Las Jarillas granites. The Tubutama group occurs east of the town of Tubutama. It includes the Tubutama, El Encino, and San Francisco granites. Besides the Magdalena granites, we also investigated some intrusive units interpreted to be arc-related and part of CEMMA, including the Sierra Guacomea granodiorite, the Cañada Honda granodiorite, and the Sierra Madera syenogranite (Figure 1; Table 1). Rock descriptions based on field observations, hand sample characteristics, and petrographic analyses are presented below and summarized in Supplementary File S1.

 

 

Magdalena Group

Sierra Guacomea area

Gneissic rocks exposed along the western range front of Sierra Guacomea were first assigned a Precambrian age by Salas (1968) but later interpreted by Anderson et al. (1980) to be mylonitized pluton with a zircon U-Pb ID-TIMS crystallization age of 78 ± 3 Ma. We refer to this pluton as the Sierra Guacomea granodiorite and analyzed sample 3-18-19-2 for zircon U-Pb geochronology and samples 3-18-19-2 and G-206 for geochemistry. Subsequent mapping by Nourse (1989, 1990) showed that the pluton is a zoned porphyritic biotite granodiorite-monzogranite sill, 11 km long by 200 to 600 m thick, intruded into the base of a strongly foliated section of Jurassic rhyolite, granite porphyry, volcaniclastic conglomerate, and quartzose sandstone, including the Middle Jurassic El Rincon granite (González-León et al., 2021). The granodiorite is distinguished by accessory titanite, garnet, and magmatic epidote.

The relatively melanocratic Sierra Guacomea granodiorite is sharply crosscut by abundant interconnected dikes and sills associated with the Cañada Tescalama granite (Figures 1, 2a). The Cañada Tescalama granite is a hundreds-meter thick, NE-dipping sill complex of medium-grained, leucocratic, garnet-biotite monzogranite locally crosscut by aplite and pegmatite dikes (Nourse, 1989, 1990) (Figures 2b–2c). A subtle mylonitic quartz grain-shape fabric is locally developed in the granite. We analyzed sample 3-25-17-3 from the Cañada Tescalama granite for zircon U-Pb geochronology and samples 3-25-17-3 and 3-18-19-1 for geochemistry.

 

 

 

The La Mariana granite outcrops as a pluton in the southern part of Sierra Guacomea and the eastern part of Sierra La Jojoba (Figure 1). It intrudes Jurassic volcanic, sedimentary, and intrusive rocks, and Cretaceous sedimentary rocks (González-León et al., 2017). The granite is a fine- to medium-grained, leucocratic garnet-biotite granite locally intruded by pegmatitic dikes. La Mariana granite is weakly foliated and discontinuous, thin bands of dynamically recrystallized quartz fill spaces between feldspars. We analyzed sample 3-26-17-5 from the La Mariana granite for zircon U-Pb geochronology and samples 3-26-17-5 and 7-7-16-2 for geochemistry (Table 1).

Sierra Magdalena area

Basement rocks, including the El Salto augen gneiss, are locally exposed in the footwall of the El Salto normal fault, in the El Salto arroyo west of Sierra Magdalena (Figure 1). Sharply crosscutting the El Salto augen gneiss and other strongly mylonitized granodioritic to leucogranitic orthogneisses in this locality is the El Salto granite, a coarse-grained, leucocratic, biotite syenogranite. We report zircon U-Pb ID-TIMS data from the El Salto augen gneiss (sample 304), the El Salto granite (sample 305), and a metapegmatite sill (sample 303). These samples were collected by Lee Silver and Tom Anderson in 1980 and subsequently analyzed by Lee Silver but not previously reported. The El Salto granite appears to postdate most of the mylonitic fabrics in its host gneisses.

The Rancho La Esperanza granite outcrops in the ridge located immediately west of arroyo El Salto and Sierra Magdalena (Figure 1). The pluton is leucocratic, medium- to coarse-grained, porphyritic, two mica-garnet granite, with K-feldspar crystals as large as 5 cm and is crosscut by pegmatitic dikes. The Rancho La Esperanza granite is foliated and mylonitization increases toward the south and the Magdalena-Tubutama detachment fault. We analyzed samples 1-22-17-1 and 1-24-17-2 from the Rancho La Esperanza granite for zircon U-Pb geochronology and samples 1-22-17-1, 1-24-17-2, 8-7-18-1, and 3-16-19-2 for geochemistry (Table 1).

The Sierra Magdalena granite outcrops in the central and western Sierra Magdalena (Figures 1 and 2d). This granite is a mylonitized, fine- to coarse-grained, porphyritic biotite-titanite granite. We analyzed sample 1-24-17-6 from the Sierra Magdalena granite for zircon U-Pb geochronology and samples 1-24-17-6, 1-24-17-8, and 7-8-16-5 for geochemistry (Table 1). On the eastern flanks of Sierra Magdalena at deeper structural levels (Figure 2e), the Cañada Honda granodiorite is exposed as large xenoliths and screens enveloped within a two mica-garnet granite referred to here as the La Piocha granite. The relatively melanocratic Cañada Honda granodiorite is a medium-grained, epidote-titanite-garnet-biotite granodiorite. The proportion of granodiorite diminishes relative to the two mica-garnet granite toward the north and west, and both units are crosscut by leucogranite aplite and pegmatite dikes. All lithologies have a mylonitic fabric that becomes stronger to the south and may be statically annealed locally. The character of the contact between the Cañada Honda granodiorite and La Piocha granite varies. In some locations, the contact is relatively discordant and sharp and in other locations, the contact is diffuse and irregular (Figure 2f). We analyzed samples 1-25-17-3 and MEX-SON-3 from the Cañada Honda granodiorite for zircon U-Pb geochronology and samples 1-25-17-3 and MEX-SON-3 for geochemistry. We also analyzed sample 9-24-16-1 from the La Piocha granite for geochemistry.

Southwest of the town of Imuris (Figure 1), the Terrenate granite intrudes Mesozoic metapelitic schist and is crosscut by the San Ignacio granite. All lithologies are mylonitized. The Terrenate granite is a saccaroid, locally porphyritic, fine- to coarse-grained and foliated leucocratic two mica-garnet granite (Figure 2g–2h). The pluton has abundant, meter-sized xenoliths of quarztofeldespathic schist. We analyzed sample 10-16-18-2 from the Terrenate granite for zircon U-Pb geochronology and samples 7-8-16-1, 7-8-16-3. 1-25-17-1, and 1-25-17-4 for geochemistry (Table 1). The San Ignacio granite is a porphyritic, two mica leucogranite. Accessory biotite, muscovite, titanite, garnet, and zircon tend to form glomerocrysts. We analyzed sample 10-16-18-1 from the San Ignacio granite for zircon U-Pb geochronology and samples 10-16-18-1, 3-17-19-1, and 3-17-19-2 for geochemistry (Table 1). At deep structural levels, 2 km northwest of sample 10-16-18-1, screens of melanocratic biotite granodiorite gneiss are contained in the San Ignacio granite.

Sierra Madera area

The Sierra Madera syenogranite is a large pluton in the central Sierra Madera that is mylonitized along its northern contact. The intensity of mylonitic fabrics diminishes southward. This relatively melanocratic pluton is a coarse-grained, porphyritic epidote-sphene-garnet-biotite syenogranite and is intruded to the north and south by the leucocratic Sierra Madera granite, which is generally undeformed (Nourse, 1989; 1990). Sills of sheared pegmatite and aplite are localized along this south-dipping contact. Several km farther south, deformed screens of syenogranite are interlayered with sheets of mylonitic, leucocratic two-mica granite similar to the Sierra Madera granite.

The Sierra Madera granite is compositionally zoned from a medium- to fine-grained, two mica-garnet monzogranite on the western flanks of Sierra Madera to a medium-grained, slightly porphyritic, biotite monzogranite with K-feldspar phenocrysts near the microwave tower at the ridgetop. The northern margin of the Sierra Madera granite preserves a sharp intrusive contact with Jurassic stretched-cobble conglomerate. The Sierra Madera granite is texturally and mineralogically similar to the San Ignacio granite, but these two units are discussed separately here and arbitrarily separated by Mexican Federal Highway #2. We analyzed sample MEX-SON-1 from the Sierra Madera syenogranite and sample SM3 from the Sierra Madera granite for zircon U-Pb geochronology and we report zircon U-Pb ID-TIMS data from sample SM3 that was collected by Tom Anderson in 1978 and subsequently analyzed by Lee Silver but not previously reported (Table 1).

Tubutama Group

The Tubutama granite is a pluton with an exposed surface area of ca. 100 km2 that outcrops immediately north and east of the town of Tubutama in the western part of the study area (Figure 1). This unit is a foliated and lineated, coarse-grained, porphyritic, two mica-garnet granite with K-feldspar crystals as large as 5 cm (Grijalva Espinoza, 2023) (Figure 2i). In the northern part of the pluton, the grain size decreases to very-fine grained. We analyzed samples 9-23-20-1, 9-23-20-4, and 9-21-20-1 from the Tubutama granite for zircon U-Pb geochronology and samples 9-23-20-1, 9-23-20-2, 9-23-20-4, and 9-21-20-1 for geochemistry (Table 1).

East of the town of Tubutama, the San Francisco granite outcrops as a N-S elongated pluton in the southwestern part of the Sierra El Álamo Viejo (Figure 1). The granite intrudes into Jurassic quartzofeldspathic schists and metasandstones of the La Jojoba metasandstone (Sánchez-Navarro, 2018; González-León et al., 2021). It is a leucocratic, foliated, two-mica-garnet granite that is intruded by aplite and pegmatite dikes and containing abundant cm- to m-scale xenoliths of metasedimentary rocks. K-feldspar porphyroclasts are up to 5 cm in diameter. We analyzed sample 3-27-17-3 from the San Francisco granite for zircon U-Pb geochronology and samples 3-27-17-3, 1-23-17-5, and 8-24-16-1 for geochemistry (Table 1).

Approximately 10 km northeast of the San Francisco granite is the El Encino granite, a leucocratic, foliated, two-mica-garnet granite that intrudes Jurassic metavolcanic and metasedimentary rocks (González-León et al., 2021). The granite becomes coarser, megacrystic to the south, and contains xenoliths of metasedimentary rocks. We analyzed sample 12-9-17-5 from the El Encino granite for zircon U-Pb geochronology and samples 12-9-17-5 and 12-9-17-2 for geochemistry (Table 1).

Yegua Group

In the eastern Sierra La Yegua-El Potrero (Figure 1), the La Yegua granite intrudes Lower Cretaceous metasedimentary rocks and the Late Jurassic La Cebolla granite as meters-thick sills and dikes (Vázquez Salazar, 2018). The La Yegua granite is a mylonitized, leucocratic, medium- to coarse-grained two mica-garnet granite with abundant, large (tens of meters diameter) metasedimentary xenoliths. Sánchez-Navarro et al. (2025) reported a combined zircon U-Pb LA-ICP-MS age of 47 Ma data from samples 12-11-17-2, 7-8-18-1 and 7-8-18-2. We discuss the same data but calculate individual dates for each sample (Table 1). We analyzed samples 7-8-18-1 and 7-8-18-2 for geochemistry.

Immediately east of Sierra La Yegua, the Las Jarillas granite outcrops in western Sierra Las Jarillas where it occurs as stocks, sills, and dikes that intrude metasedimentary rocks of Early Cretaceous age (Vázquez Salazar, 2018). The Las Jarillas granite is a mylonitized, coarse-grained, leucocratic two-mica-garnet granite with saccharoidal texture. Sánchez-Navarro et al. (2025) reported a weighted mean zircon U-Pb age of 60 Ma for the Las Jarillas granite. We analyzed samples 9-23-16-2, 9-23-16-5, 10-7-17-8, and 7-28-17-6 (a dike) for geochemistry.

 

METHODS

Field-work and new 1:50000 scale geologic mapping was performed in the study area to produce the geologic map presented in Figure 1. This map builds upon the more detailed geologic mapping of Mesozoic and older rocks reported in González-León et al. (2021) and the geologic mapping of Nourse (1989; 1990) in the eastern half of the study area. The lithologic contacts surrounding most of the granites studied are gradational and only approximately located. Furthermore, many granites studied form intrusive complexes that include numerous dikes, sills, and small intrusive bodies. This complex geometry is not captured at the map scale presented in Figure 1.

During fieldwork, we collected representative rock samples from the freshest, least weathered outcrops for further analysis. In general, we preferentially sampled fine- to medium-grained facies of the granites (e.g., avoided pegmatite and megacrystic samples) to aid in petrographic and geochronologic analyses. Petrographic thin sections were made, and whole rock powders and mineral separates were produced at the Estación Regional del Noroeste (ERNO), Instituto de Geología, Universidad Nacional Autónoma de México (UNAM) in Hermosillo, Sonora. Approximately 50 zircon grains from each sample were cast in epoxy mounts and polished to expose the interior of the zircon crystals.

Zircon crystals were imaged for cathodoluminescence (CL) and analyzed for U-Pb geochronology at the Laboratorio de Estudios Isotópicos, Instituto de Geociencias, UNAM in Juriquilla, Querétaro by LA-ICP-MS following the methodology described in Solari et al. (2018), except for sample SM3 that was analyzed by LA-ICP-MS and imaged using CL at the University of California, Santa Barbara (UCSB) following the procedures in Kylander-Clark et al. (2013). UNAM LA-ICP-MS analyses were performed using a Thermo Scientific iCAP Qc quadrupole ICP-MS coupled with a Resolution M050 excimer laser with a laser spot diameter of 23 µm. UCSB LA-ICP-MS analyses were performed using a Nu Intrstruments Nu Plasma HR-ES multi-collector (MC)-ICP-MS coupled to a Photon Machines 193 excimer laser with a laser spot diameter of 15 µm. Zircon reference materials were 91500 (ca. 1063 Ma, Wiedenbeck et al., 1995) as a primary standard and Plešovice (ca. 337 Ma, Sláma et al., 2008) as a secondary (control) standard. During the analytical sessions of this study, analyses of the Plešovice zircon standard yielded an average 206Pb/238U age of 338.7± 1.6 Ma (MSWD= 1.8, n= 47), in agreement with published values. No common Pb correction was applied, since the 204Pb signal is swamped by the isobar 204Hg contained in the carrier gas. Many young (< 100 Ma) zircon U-Pb dates exhibit discordance, which may be produced by various factors, including the difficulty in measuring low 207Pb signals in young zircon crystals. We did not universally apply a discordance filter but dealt with discordance on a sample-by-sample basis, as described in the results section. Percent discordance was calculated using (207Pb/235U date - 206Pb/238U date) / 207Pb/235U date. Unless otherwise specified (e.g., for some Proterozoic dates), all dates discussed below are 206Pb/238U dates. Weighted mean ages are calculated from 206Pb/238U dates and uncertainty is reported at the 2σ level by adding in quadrature average single grain date uncertainty and standard deviation of the dated population. This uncertainty estimate is conservative (large uncertainties) and helps to reflect the full range of dates included within age estimations. All the reported ages are calculated using IsoplotR (Vermeesch, 2018) and listed in Table 1. Full analytical results for LA-ICP-MS geochronologic data are presented in Supplementary File S2. NIST 610 synthetic glass was used as an external standard to calculate elemental concentrations in zircon, using 29Si as an internal standard for zircon. Standards were interspersed throughout the analytical sequence, repeating measurements twice for each ten unknown zircon analyses. The obtained raw data were reduced offline using Iolite v. 4.1 (Paton et al., 2011). Full analytical results for zircon geochemical data are presented in Supplementary File S3.

We report zircon U-Pb ID-TIMS data from five samples from the Magdalena area analyzed by L.T. Silver at Caltech between 1970 and 1983 but not previously published. After L.T. Silver’s death in 2022, J. Nourse cataloged, organized, and archived samples and data from the Caltech ID-TIMS lab. The data presented here were recovered during that effort. Full analytical results for ID-TIMS data are presented in Supplementary File S4. A detailed description of sample preparation and ID-TIMS analytical methods, including treatment of uncertainty, is presented in Supplementary File S5.

Whole rock powders were analyzed for major element concentrations in fused beads by X-ray fluorescence at the Laboratorio Nacional de Geoquímica y Mineralogía (LANGEM), UNAM in México City, following the procedures indicated in González-León et al. (2017). Trace element contents were determined by ICP-MS at the Instituto de Geociencias (CGEO), UNAM in Juriquilla, Querétaro with a Thermo Scientific iCAP Qc quadrupole ICP-MS following the procedures indicated in Mori et al. (2007). Sample preparation was performed in a clean lab and trace elements were determined using 50 mg of powdered sample digested in 1 mL HF plus 0.5 mL HNO3 in closed screw-top Savillex Teflon vials heated overnight at 100 °C. Acids were evaporated to dryness and then fluxed twice with 15 drops of 16 M of HNO3 to break down fluorides. Once the acid was evaporated, 2 mL deionized water plus 2 mL 8 N HNO3 were added, and the samples were left closed overnight at 100 °C. All samples were then diluted to 1:2000 to achieve concentrations within the instrument’s detection limits. All samples were diluted with an internal standard solution to monitor instrumental drift. Calibration and data reduction were based on the digestion of four international rock standards (AGV_2, BHVO-2, JB-2, BCR-2 and JR-1). Full analytical results for whole-rock geochemical analyses are reported in Supplementary File S6.

 

RESULTS

 

Magdalena Group geochronology

Sierra Guacomea area

All zircon U-Pb data reported below are LA-ICP-MS results unless otherwise noted. Sample 3-18-19-2 was analyzed from the Sierra Guacomea granodiorite and yielded two date populations: 23 zircon U-Pb dates ranging from 180 to 145 Ma, interpreted as inherited zircon, and nine zircon U-Pb dates ranging from 73 to 63 Ma. The nine youngest dates are all concordant and have a weighted mean age of 66.2 ± 3.6 Ma, but the two youngest dates do not overlap within uncertainty with the other dates. These analyses may have included age domains (e.g., zircon rims) related to melt infiltration (see Discussion section below) or have suffered from Pb loss. Excluding these two analyses, the sample has a weighted mean age of 68.8 ± 3.5 Ma, which is interpreted as the crystallization age of the granodiorite (Figure 3a). The results are comparable with U-Pb ID-TIMS dates for two zircon fractions from a sample of the Sierra Guacomea granodiorite reported in Anderson et al. (1980) (solid black ellipses in Figure 3a).

 

 

Sample 3-25-17-3 was collected from the Cañada Tescalama granite and yielded 35 zircon U-Pb dates that range from 70 to 54 Ma. Three date populations are apparent after removing discordant analyses. These include an older population with dates ranging from 68 to 66 Ma (weighted mean age = 66.7 ± 0.8 Ma; n=7), an intermediate population of ca. 62 Ma dates (weighted mean age = 62.4 ± 0.7 Ma; n=6), and a young population with dates ranging from 59 to 57 Ma (weighted mean age = 58.6 ± 1.0 Ma; n=12) (Figure 3b). The older date population is similar to the age of the Seirra Guacomea granodiorite that the Cañada Tescalama granite intrudes (sample 3-18-19-2; Figure 3a). We interpret this population to consist of inherited zircon. Zircon U concentrations in sample 3-25-17-3 are high, ranging from 2600 to 17300 ppm (median = 6300 ppm), which may make the zircon crystals prone to Pb loss. If the young date population experienced Pb-loss, the intermediate date population may be most representative of the granite’s crystallization age. However, there is a weak positive correlation between date and U concentration, the opposite trend expected for zircon that have experienced Pb loss because of radiation damage. As a result, the youngest population of concordant dates is interpreted to represent the crystallization age. The intermediate date population (ca. 62 Ma) may represent mixed-age domain analyses.

Sample 3-26-17-5 was collected from the La Mariana granite and yielded a middle Jurassic to Early Cretaceous zircon U-Pb date population ranging from 174 to 123 Ma (n=13), a Late Cretaceous zircon U-Pb date population (ca. 75 Ma, n=3), and a Paleogene zircon U-Pb date population ranging from 45 to 59 Ma (n=16). The Paleogene date population contains six discordant analyses, five of which form a poorly defined discordia that has a lower intercept within uncertainty of seven concordant analyses (Figure 3c). For these 12 analyses, the weighted mean age is 49.6 ± 1.6 Ma and the lower intercept discordia age on a Tera-Wasserburg diagram is 49.0 ± 0.4 Ma (MSWD=5).

 

Sierra Magdalena area

Sample 304, from the El Salto augen gneiss, yielded three discordant zircon U-Pb ID-TIMS analyses that have an upper intercept discordia age on a Wetherill diagram of 1089 ± 7 Ma (MSWD=3.8) (Figure 4a), interpreted as the crystallization age of the orthogneiss protolith. The augen gneiss is crosscut by the El Salto granite (sample 305) and a metapegmatite (sample 303). Sample 305 yielded 4 discordant zircon U-Pb ID-TIMS analyses that have an upper intercept Wetherill discordia age of 1449 ± 19 Ma and a lower intercept discordia age of 48.6 ± 1.0 Ma (MSWD=1.1) (Figure 4b). The upper intercept age is interpreted to represent inherited age components of local basement rocks and the lower intercept is interpreted as the crystallization age of the El Salto granite. A single zircon U-Pb ID-TIMS analysis from sample 303 yielded a nearly concordant (2 % discordance) 206Pb/238U date of 40.6 ± 0.5 Ma, interpreted as the crystallization age of the pegmatite.

 

 

Two samples were collected from the Rancho La Esperanza granite, one from a northern exposure of the granite (1-22-17-1) and one from a southern exposure of the granite (1-24-17-2) (Figure 1). Sample 1-22-17-1 yielded a Cretaceous zircon U-Pb date population ranging from 90 to 70 Ma (n=4) and an Eocene zircon U-Pb date population with dates with < 15 % discordance ranging from 52 to 42 Ma (n=14). The youngest 13 of these dates form a coherent population and have a weighted mean age of 43.1 ± 1.4 Ma (Figure 3d). Sample 1-24-17-2 yielded a Jurassic zircon U-Pb date population ranging from 167 to 145 Ma (n=3), a Late Cretaceous to Paleocene zircon U-Pb date population ranging from 75 to 61 Ma (n=7), and an Eocene zircon U-Pb date population with concordant dates ranging from 54 to 41 Ma (n=16). The 13 youngest dates define a coherent population with a weighted mean age of 42.5 ± 1.5 Ma (Figure 3e). Combining analyses from both samples yields a weighted mean age of 42.8 ± 1.3 Ma (n=28).

Sample 1-24-17-6 was collected from the central portion of the Sierra Magdalena granite and yielded a Proterozoic zircon U-Pb date population (ca. 1.5 to 1.0 Ga; n=6), a Mesozoic zircon U-Pb date population (165 to 74 Ma; n=4) and a coherent Paleogene zircon date population with concordant ages ranging from 51 to 45 Ma that have a poorly defined weighted mean age of 49.0 ± 3.8 Ma (n=14) (Figure 3f). The range of dates is relatively continuous, but it is possible that the older dates in this population reflect inheritance with variable amounts of Pb loss. The seven youngest concordant analyses yield a weighted mean age of 46.1 ± 1.0 Ma, our best approximation of the granite crystallization age.

Samples 1-25-17-3 and MEX-SON-3 were collected from the Cañada Honda granodiorite. Sample 1-25-17-3 yielded 9 Proterozoic zircon U-Pb dates ranging from 1655 to 1014 Ma, a Cretaceous zircon U-Pb date population ranging from 76 to 70 Ma with a weighted mean age of 71.9 ± 2.2 Ma (n=5), two Paleocene dates, and an Eocene zircon U-Pb date population ranging from 50 to 37 Ma (n=17). The Eocene date population is relatively continuous in its distribution, but the youngest 14 concordant dates form a coherent population with a weighted mean age of 39.8 ± 2.4 Ma (Figure 3g). Sample MEX-SON-3 yielded a Cretaceous zircon U-Pb date population with a cluster of 10 dates with a weighted mean age of 71.7 ± 3.0 Ma (n=10), a Paleocene date population with a weighted mean age of 59.6 ± 1.3 Ma (n=4), and an Eocene U-Pb date population. The youngest 6 concordant analyses have a weighted mean age of 41.7 ± 1.0 Ma (Figure 3h). Two zircons from sample MEX-SON-3 were also analyzed by ID-TMIS and are discordant, but have an upper Wetherill discordia age of 1198 ± 35 Ma and a lower intercept discordia age of 43.9 ± 1.8 Ma (Figure 4c). The upper intercept age is interpreted to represent inherited age components of local basement rocks and the significance of the lower intercept is reviewed in the discussion section below.

Sample 10-16-18-2 was collected from the Terrenate granite and yielded an Eocene zircon U-Pb date population ranging from 42 to 48 Ma (n=24). Many of these analyses showed varying degrees of discordance attributed to difficulty in measuring a low 207Pb signal. Considering analyses with <15 % discordance, the weighted mean age of sample 10-16-18-2 is 44.8 ± 1.8 Ma (n=16) (Figure 3i). Sample 10-16-18-1 was collected from the San Ignacio granite and yielded three Jurassic zircon U-Pb dates (180, 180, and 169 Ma) and an Eocene zircon U-Pb date population with < 15 % discordance ranging from 46 to 38 Ma (n=9). The 7 youngest of these grains define a coherent population with a weighted mean age of 40.2 ± 1.5 Ma (Figure 3j).

 

Sierra Madera area

Sample MEX-SON-1 was collected from the Sierra Madera syenogranite and sample SM3 was collected from the Sierra Madera granite, which crosscuts the syenogranite. Sample MEX-SON-1 yielded a Jurassic date population ranging from 176 to 145 Ma (n=9), a Late Cretaceous-Paleocene date population with a weighted mean age of 60.7 ± 2.7 Ma (n=8), and a young population ranging from 31 to 46 Ma with a weighted mean age of 39.5 ± 5.6 Ma (n=11). The youngest 6 grains that overlap within error have a weighted mean age of 32.7 ± 2.2 Ma. (Figure 3k). Sample SM3 yielded an older population ranging from 77 to 61 Ma (n=24), an intermediate date population ranging from 48 to 54 Ma (n=4), and a young population ranging from 38 to 42 Ma. The 13 youngest concordant dates in the older population have weighted mean age of 62.7 ± 1.4 Ma and the 8 youngest analyses overlapping within uncertainty in the youngest population have a weighted mean age of 38.4 ± 0.6 Ma. (Figure 3l). Sample SM3 was also analyzed by ID-TMIS and yielded two discordant analyses with an upper Wetherill discordia age of 1402 ± 24 Ma and a lower intercept discordia age of 39.6 ± 0.7 Ma (Figure 4d). The upper intercept age is interpreted to represent inherited age components of local basement rocks and the lower intercept age is interpreted as the crystallization age of the granite.

 

Tubutama Group geochronology

Sample 3-27-17-3 was collected from the San Francisco granite and yielded 3 concordant Proterozoic zircon U-Pb dates (1800, 1700, and 972 Ma), two concordant Cretaceous zircon U-Pb dates (82 and 76 Ma), and an Eocene zircon U-Pb concordant date population ranging from 54 to 44 Ma (n=21). Excluding the youngest date, the next youngest 15 dates form a coherent population with a weighted mean age of 47.6 ± 1.1 Ma (Figure 5a).

 

 

Three samples from different locations of the western part of the Tubutama granite were collected and analyzed. Sample 9-23-20-1, from the northern part of the pluton, yielded 2 Proterozoic zircon U-Pb dates (1718 and 1379 Ma), a Jurassic zircon U-Pb date population ranging from 167 to 151 Ma with a weighted mean age of 160.5 ± 6.1 Ma (n=9), a Cretaceous zircon U-Pb date population ranging from 126 to 87 Ma (n=6), a mostly Paleocene zircon U-Pb date population ranging from 57 to 54 Ma with a weighted mean age of 56.0 ± 1.1 Ma (n=5), and an Eocene zircon U-Pb date population ranging from 49 to 51 Ma with a weighted mean age of 46.9 ± 1.7 Ma (n=9) (Figure 5b). Sample 9-21-20-1, from the southern part of the pluton, yielded 3 Proterozoic zircon U-Pb dates (2378, 2078, and 1740 Ma), a Jurassic to Early Cretaceous zircon U-Pb date population ranging from 168 to 141 Ma (n=5), a Paleocene zircon U-Pb date population ranging from 61 to 57 Ma (n=4), and a bimodal Eocene zircon U-Pb concordant date population ranging from 54 to 46 Ma (n=16). The younger mode has a weighted mean age of 47.1 ± 0.8 Ma (n=10). The older mode has a weighted mean age of 52.9 ± 1.2 Ma (n=5) (Figure 5c). Sample 9-23-20-4, from the central part of the pluton, yielded 9 Proterozoic zircon U-Pb dates, including a date population centered on ca. 1.0 Ga (n=7), three Late Cretaceous zircon U-Pb dates (80, 77, and 76 Ma), and an Eocene zircon U-Pb date population ranging from 55 to 46 Ma (n=17). The youngest 15 analyses from sample 9-23-20-4 form a coherent date population with a weighted mean age of 48.3 ± 1.6 Ma (Figure 5d). Combing the youngest zircon U-Pb date populations from all three samples yields a weighted mean age of 47.4 ± 1.7 Ma (n=34).

Sample 12-9-17-5 was collected from the El Encino granite. It yielded a Jurassic zircon U-Pb date population ranging from 170 to 150 Ma (n=5), an early Eocene to Paleocene zircon U-Pb date population with a weighted mean age of 56.5 ± 1.1 Ma (n=14), and a middle Eocene zircon U-Pb date population with a weighted mean age of 48.1 ± 2.1 Ma (n=7) (Figure 5e).

 

La Yegua Group geochronology

Sánchez-Navarro et al. (2025) reported a combined zircon U-Pb LA-ICP-MS age of 47 Ma from samples 12-11-17-2, 7-8-18-1, and 7-8-18-2 of the La Yegua mylonitic granite. We report data from individual samples below. Sample 12-11-17-2, collected from the southern part of Sierra La Yegua, yielded a Jurassic zircon U-Pb concordant date population ranging from 177 to 159 Ma (n=9), a mostly early Eocene zircon U-Pb date population, ranging from 57 to 48 Ma (n=13), which consists mainly of discordant analyses (≤ ~27 % discordance), and two middle Eocene zircon U-Pb dates (40 and 42 Ma) that are also discordant (ca. 23 % discordance). The weighted mean age of the 11 youngest analyses of the early Eocene population from sample 12-11-17-2 is 51.4 ± 1.8 Ma (Figure 5f). Sample 7-8-18-1, collected from the central part of Sierra La Yegua, yielded a Jurassic zircon U-Pb concordant date population ranging from 191 to 150 Ma (n = 5) and an Eocene zircon U-Pb date population ranging from 49 to 43 Ma (n = 4) with a weighted mean age of 46.1 ± 2.3 Ma (Figure 5g). Sample 7-8-18-2, collected from the northern part of Sierra La Yegua, yielded an Eocene zircon U-Pb date population ranging from 51 to 44 Ma (n = 28), with many discordant analyses (>10 % discordance, n=12). Excluding two ca. 44 Ma concordant dates that form a sub-population, the weighted mean age of the Eocene population is 48.3 ± 1.5 Ma (n = 26) (Figure 5h). Removal of the discordant dates does not alter the weighted mean age of the sample.

 

Geochemistry

Whole-rock major and trace-element concentrations discussed below were recalculated to 100 % on an anhydrous basis. The normalized silica contents of the Magdalena granites range from 71 to 78 wt. % SiO2. All samples are corundum normative, and normative minerals indicate mostly granitic compositions for the analyzed samples (Figure 6a). The R1-R2 cationic elemental compositions of major oxides indicate that these samples can be classified as granite or alkali granite and overlap with the composition of anatectic granites defined by Batchelor and Bowden (1985) (Figure 6b). The aluminum saturation index corrected for apatite (Frost et al., 2001; Bonin et al., 2020), defined as the molecular ratio Al/(Ca – 3.33*P + Na + K), ranges from 1.0 to 1.3 indicating that the Magdalena samples are moderately peraluminous (Figure 6c). Absolute rare earth elements (REE) concentrations of the Magdalena granites are variable (Figure 7), with ∑REE ranging from 8.4 to 189.3 ppm. Most of the samples have negative chondrite-normalized LREE slopes, (La/Sm)n > 1, and positive chondrite-normalized HREE slopes (Gd/Lu)n < 1 (Figure 7a). Compared to the more mafic samples (MgO > 0.5), the more felsic samples (MgO < 0.5) are depleted in LREE and enriched in HREE (Figure 7a). Eu anomalies vary from 0.1 to 4.6, but are generally slightly negative, except for nine samples with positive Eu anomalies and the lowest values of ∑REE. On a NMORB normalized multi-element diagram (Figure 7b), the Magdalena granites are enriched in large ion lithophile elements (LILE) and depleted in high field strength elements (HFSE) with positive K and Pb anomalies and prominent negative Nb, Ta, P, Zr, Hf, and Ti anomalies.

 

 

 

 

Zircon trace element concentrations were measured for samples analyzed for zircon U-Pb geochronology. Total REE concentrations for the Magdalena granites range from 230 to 9030 ppm (median = 2180 ppm). In general, the range of zircon trace element concentrations overlaps from one sample to another; however, some geochemical differences become more apparent when plotted against zircon U-Pb date and when compared to inherited zircon and zircon from CEMMA (e.g., Sierra Guacomea granodiorite). Zircon from the Magdalena granites generally have lower Ti concentrations (median = 2.8 ppm), higher U/Th ratios (median = 11.5), lower Eu/Eu* (EuN/[{SmN+GdN}0.5]) (median = 2.8 ppm), and lower (Gd/Yb)n (median = 0.022) compared to inherited and CEMMA zircon that have median Ti concentrations = 4.1 ppm, median U/Th = 4.5, median Eu/Eu* = 4.1, and median (Gd/Yb)n = 0.028 (Figure 8). Higher U/Th in zircon from the Magdalena granites is consistent with CL images that show CL dark domains (mostly zircon rims) enriched in U compared to CEMMA zircon characterized by low U, CL light domains (mostly zircon cores) that display oscillatory and sector zoning (Figure 9).

 

 

 

DISCUSSION

Affinity to the North American Cordilleran Anatectic Belt

In the following section, we discuss several characteristics of the Magdalena granites that suggest they are part of the North American Cordilleran Anatectic Belt and distinct from CEMMA. In addition to the Magdalena granites, there is a small subset of intrusive rocks that were included within the compilation of CEMMA rocks presented by Valencia-Moreno et al. (2021) that we consider to be part of the North American Cordilleran Anatectic Belt. We refer to this sample subset as the core complex leucogranites. Like the Magdalena granites, the core complex leucogranites are located in the footwalls of metamorphic core complexes in Sonora, including the Mezquital, Mazatán, Puerta del Sol, and Aconchi complexes (Anderson et al., 1980; Roldán-Quintana, 1991; Nourse et al., 1994, 1995; González-León et al., 2011; González-Becuar et al., 2017). Previous studies suggested that these leucogranites may be related to crustal melting (González-Becuar et al., 2017; Nourse et al., 2018; Chapman et al., 2021).

One of the characteristics of the Magdalena granites and core complex leucogranites is that they are conspicuously young. For the Magdalena granites, all but a few samples (e.g., Cañada Tescalama granite and Las Jarillas granite) have weighted mean crystallization ages < 50 Ma (Table 1, Figure 10a). In northwestern Mexico, there is a notable lull in magmatism starting at ~51 Ma that is interpreted to be associated with the end of arc magmatism (i.e., CEMMA) and a transition to extension-related magmatism (Ferrari et al., 2018). The crystallization ages of the core complex leucogranites, estimated by Valencia-Moreno et al. (2021) using zircon U-Pb and hornblende Ar/Ar and K-Ar dates, are also some of the only rocks in Sonora younger than 50 Ma in the CEMMA compilation (Figure 10b). The next youngest group of magmatic rocks in Sonora are generally ≤ 30 Ma and related to mid-Cenozoic extension and ignimbrite volcanism (McDowell et al., 1997). Thus, the Magdalena granites intruded immediately after the end of arc magmatism and before the onset of extension-related magmatism in Sonora. These age characteristics are the same for anatectic granites in the southern U.S. Cordillera, which intruded as arc-magmatism was waning or had ended but before extension-related magmatism had begun (Chapman et al., 2021).

 

 

Most of the Magdalena granites also exhibit a relatively large range of individual zircon U-Pb dates, even after excluding unequivocally inherited zircon (generally > 65 Ma) and discordant analyses. In several samples (e.g., Sierra Magdalena, La Mariana, San Francisco, Tubutama granites) the range of dates exceeds 10 Myr (Figure 10a). The wide range of individual zircon U-Pb dates (~10 Myr) is a common characteristic of granites in the North American Cordilleran Anatectic Belt, granites in other anatectic province globally (e.g., Himalayan leucogranites; Lederer et al., 2013), and is thought to represent complex melt processes, including prolonged crystallization times (Chapman et al., 2021; 2023). For many igneous rocks, including arc-related magmatism, there is a common assumption that a single zircon U-Pb crystallization age should be observed, and that deviations from this age may represent analytical uncertainty or compromised analyses (e.g., Pb loss). For anatectic granites, related to potentially long-lived metamorphic processes in the deep crust, it is unclear if a single crystallization age is applicable (cf. Weinberg, 2016; Farina et al., 2018; Chapman et al., 2023).

One feature of anatectic intrusive suites is a bimodal population of zircon U-Pb crystallization dates, reflecting a temporary hiatus in zircon crystallization. This feature is common in the Himalayan anatectic leucogranites (Zeng et al., 2015; Cottle et al., 2018; Ding et al., 2021; Ji et al., 2022) and has also been documented in granites from the North American Cordilleran Anatectic Belt in southern Arizona (Davis et al., 2019; Chapman et al., 2023). The hiatus in zircon dates has been interpreted to reflect a switch from zircon crystallization to zircon dissolution to maintain Zr saturation in the melt during prograde metamorphism as the melt fraction increases, diluting the melt in Zr (Kelsey and Powell, 2011; Kohn et al., 2015; Yakymchuk et al., 2017; Chapman et al., 2023). After excluding inherited dates (> 65 Ma) and discordant analyses, all three sub-groups of the Magdalena granite have bimodal date populations (Figure 10c). However, two samples dominate the older date population in the Magdalena group and

La Yegua group, the Cañada Tescalama granite and Las Jarillas granite, respectively, which makes interpreting these populations difficult. In contrast, all rock samples from the Tubutama group contain a bimodal zircon U-Pb date population (Figure 10a). The peaks in this bimodal date population also match the peaks in the date populations from the Pan Tak granite in southern Arizona in the North American Cordilleran Anatectic Belt (Chapman et al., 2023), located ~100 km north of the Tubutama area (Figure 10c). Additional work is needed to fully interpret the range of dates from the Magdalena granites, but for the Pan Tak granite, Chapman et al. (2023) interpreted the older date population to represent antecrysts primarily formed in situ (e.g., leucosomal bodies in a migmatite) during prograde metamorphism and the younger population to represent crystallization after melt extraction from the source.

Zircon from the Magdalena granites have high U/Th ratios (median = 11.5) (Figure 8a), which is common in zircon from anatectic granites from the North American Cordilleran Anatectic Belt (Chapman

et al., 2021), but uncommon in zircon from the Laramide arc in the southern U.S. Cordillera (U/Th < 5; Chapman et al., 2018). Zircon from the CEMMA units investigated in this study have low U/Th (median = 2.8). Likewise, Late Cretaceous age, inherited zircon from the Magdalena granites, interpreted to be from CEMMA rocks, have low U/Th (median = 4.5) (Figure 8a). Elevated zircon U/Th, particularly U/Th > 10, is often associated with metamorphic environments and the growth of metamorphic monazite, sequestering Th, although the exact reasons are not always clear (Hoskin and Schaltegger, 2003; Gehrels et al., 2009). Relatively high U/Th zircon is also common in anatectic granites and we interpret the relatively high zircon U/Th in the Magdalena granites to reflect low melt fractions, low-temperature melting near the solidus, and late-stage melt crystallization (Kirkland et al., 2015; Pineda et al., 2022; Yakymchuk et al., 2018). See details presented in the Crystallization and Melt Processes section below.

Another similarity between the Magdalena granites, the Sonoran core complex leucogranites, and anatectic granites in the North American Cordilleran Anatectic Belt is their location and intrusive characteristics. These rocks primarily outcrop within the footwall of metamorphic core complexes but are ca. 15 to 25 Myr older than the timing of core complex formation and exhumation in the southern U.S. and northern México (Chapman et al., 2021). Chapman et al. (2021) hypothesized that the granites in the North American Cordilleran Anatectic Belt are primarily located in core complexes because they intruded into the middle crust, which is rarely exposed outside of core complexes in the region. More thermobarometry studies are needed to test this hypothesis. The Magdalena granites also commonly intrude as extensive dike and sill networks or small plutonic bodies, and lack extrusive equivalents, unlike arc-related magmatism related to CEMMA (Valencia-Moreno et al., 2021), but similar to the North American Cordilleran Anatectic Belt (Chapman et al., 2021). In Sonora, much of the volcanic component of CEMMA was removed by erosion, but arc-related Late Cretaceous volcanic rocks remain locally, particularly within sedimentary basins that escaped erosion during the Cenozoic (Roldán-Quintana et al., 2009; González-León et al., 2011, 2017). In contrast, the high-silica magmas associated with the Magdalena granites and the North American Cordilleran Anatectic Belt do not appear to have ever reached the surface and have no extrusive equivalents.

The Magdalena granites and core complex leucogranites are also geochemically similar to granites in the North American Cordilleran Anatectic Belt. All of these rocks are silica-rich (generally > 70 wt. % SiO2), slightly peraluminous (ASI > 1.0), corundum normative, and commonly contain muscovite (e.g., two-mica granites) and garnet as accessory minerals. CEMMA rocks from Sonora extend to significantly lower SiO2 values and are chiefly metaluminous (Figure 6c). Based on experimental melting results, Patiño-Douce (1999) produced a diagram discriminating igneous rocks related to crustal melting of metasedimentary protoliths (peraluminous leucogranite field) from arc-related, calc-alkaline granites (Cordilleran calc-alkaline and peraluminous granite field) (Figure 6d). The Magdalena granites, core complex leucogranites, and North American Cordilleran Anatectic Belt granites plot within the field of crustal melting (Figure 6d). In contrast, CEMMA rocks from Sonora plot primarily in the arc-related field. There is overlap in trace element concentrations between the Magdalena granites and CEMMA. Still, the Magdalena granites typically have slightly negative to flat LREE slopes (La/Sm close to 1) and positive HREE slopes (Gd/Lu < 1) whereas CEMMA rocks from Sonora generally have moderately negative LREE and HREE slopes (Figure 7c). Slightly negative to flat LREE slopes and flat to positive HREE slopes are also common in North American Cordilleran Anatectic Belt granites (Chapman et al., 2021).

 

Crystallization and Melt Processes

More detailed studies of individual granites are needed to fully understand crystallization and melt conditions, however the geochemical data collected in this study provide some insight into these processes. First, many of the Magdalena granites experienced advanced fractional crystallization, and their compositions likely represent residual melt after removal of late-forming phases. LREE depletion of increasingly felsic rocks (Figure 7a) and high zircon U/Th (Figure 8a-8b) are consistent with late-stage crystallization of monazite, which preferentially sequesters LREE and Th (cf. Yakymchuk et al., 2018). There are several possible causes of high zircon U/Th, but late-stage crystallization is supported by exponential increases in zircon U/Th for the youngest zircon U-Pb dates (Figure 8b). Overall, high zircon U concentrations are also consistent with a highly fractionated melt. Some of the Magdalena granites are also depleted in Zr and Hf (Figure 7b), consistent with advanced fractionation and zircon crystallization (cf. Claiborne et al., 2006).

Apart from accessory minerals, plagioclase was an important crystallizing phase. More felsic rocks exhibit a more negative Eu anomaly (Figure 7a), and the Magdalena granites have more negative zircon Eu anomalies than CEMMA rocks (Figure 8d), suggesting a more critical role of plagioclase. Some of the Magdalena granites exhibit positive Eu anomalies, but these samples also have the lowest total REE (Figure 7a), suggesting that they are likely cumulates (cf. Rudnick, 1992). The flat to positive HREE slopes (Figure 7a) support crystallization at relatively low-pressures (mid-crust to upper crust) that favors the formation of plagioclase at the expense of HREE-bearing residual phases (e.g., garnet, amphibole). The high-silica content of the Magdalena granites and their low zircon Ti concentrations (Figure 8c) suggest relatively low crystallization temperatures as well, but these values are not well constrained.

The major element composition of the Magdalena granites is consistent with the experimental results of muscovite-dehydration melting of metasedimentary rocks (Patiño-Douce, 1999; Lee et al., 2003) (Figure 6d) and there is an abundance of metasedimentary (mostly pelitic) xenoliths in the Magdalena granites. Muscovite dehydration melting may have contributed to the strong positive Pb anomaly of the Magdalena granites (Figure 7b) since Pb partitions readily into muscovite during anatexis and muscovite-rich protoliths are expected to release significant Pb into the melt during phase breakdown (Finger and Schiller, 2012). The Magdalena granites exhibit increasing Rb/Sr with decreasing Eu/Eu* (more negative Eu anomalies) and increasing Rb/Sr with decreasing Ba concentrations, both of which have been suggested to indicate water-absent, muscovite-dehydration melting (Harris and Inger, 1992; Inger and Harris, 1993; Prince et al., 2001; Weinberg and Hasalova, 2015) (Figure 11). However, these trends can also be produced by fractional crystallization of feldspar, both plagioclase and K-feldspar, which is supported by the geochemistry of the Magdalena granites. Biotite is ubiquitous in the Magdalena granites, which implies that another Fe-Mg-rich phase (not only muscovite) was likely breaking down during anatexis, potentially a biotite-dehydration reaction. The major element compositions of the Magdalena granites are generally too felsic to be primary melts produced by biotite-dehydration melting (cf. Patiño-Douce, 1999) but are consistent with biotite dehydration melting followed by fractional crystallization. Similar melt scenarios have been proposed for many Himalayan leucogranites (Scaillet et al., 1995; Liu et al., 2019; Wu et al., 2020; Yang et al., 2025). The compositions of the Magdalena granites do not support water-present melting, although water-deficient melting, proposed for some of the North American Cordilleran Anatectic Belt granites in Arizona (Chapman et al., 2023), remains a possibility.

 

 

Intrusive relationships between arc rocks and the Magdalena granites

We investigated three intrusive units in the study area that are part of CEMMA: the Sierra Guacomea granodiorite, the Cañada Honda granodiorite, and the Sierra Madera syenogranite. Several characteristics help to distinguish these units from the Magdalena granites in the field. First, they are relatively melanocratic (< 70 wt. % SiO2) with biotite and magmatic epidote and titanite. The Magdalena granites are uniformly leucocratic (> 70 wt. % SiO2), do not contain epidote, and rarely have accessory titanite. The Magdalena granites also contain muscovite, which is rarely present in the CEMMA units. Second, the Sierra Guacomea granodiorite, Cañada Honda granodiorite, and Sierra Madera syenogranite are more strongly deformed and foliated than the Magdalena granites, which in some areas are undeformed, have a weak magmatic fabric, or have only been mylonitized by deformation associated with the Tubutama and Magdalena-Madera core complexes (Nourse, 1989; 1990). Fabrics in the CEMMA units investigated include statically annealed, coaxial mylonites and gneissic textures associated with compression, crustal thickening, and burial during the Laramide Orogeny and as well as extensional mylonites associated with the core complexes (Nourse, 1989; 1990). Third, the CEMMA units investigated in this study are only exposed at the deepest structural levels within the metamorphic core complexes. Likewise, several large screens of relatively melanocratic granodiorite gneiss, interpreted to be related to CEMMA, are exposed in the deepest structural levels of fault blocks east of Terrenate and west of La Esperanza (Nourse, 1989). Finally, crosscutting relationships indicate that the CEMMA units are older than the Magdalena granites, which commonly intrude as dike/sill complexes (Figure 2).

Despite field relationships indicating the units are part of CEMMA, zircon U-Pb LA-ICP-MS analyses of the Cañada Honda granodiorite and the Sierra Madera syenogranite yielded late Eocene date populations that are similar to the crystallization ages of the surrounding Magdalena granites that intrude into them. For example, the two Cañada Honda granodiorite samples analyzed have a Late Cretaceous population (72 Ma), interpreted as the crystallization age of the granodiorite, and a younger population (40–42 Ma) (Figure 3g–3h). These two date populations are similar to those of the Rancho La Esperanza granite. The older date population (72 Ma) in the Rancho La Esperanza granite is interpreted to represent inherited, xenocrystic zircon from the Cañada Honda granodiorite or a similar CEMMA unit and the young population (43 Ma) is interpreted to be the crystallization age of the granite (Figure 3d-3e). The Sierra Madera syenogranite has a Paleocene date population (61 Ma) interpreted to be the crystallization age of the syenogranite, and a young population (40 Ma) (Figure 3k), which is similar to the interpreted crystallization age of the Sierra Madera granite (38 Ma) that intrudes into the syenogranite (Figure 3l). The Paleocene date population in the Sierra Madera granite (63 Ma) is interpreted to represent inherited, xenocrystic zircon from the Sierra Madera syenogranite.

There are a few observations that can help to explain the presence of Eocene zircon date populations in the CEMMA units with Late Cretaceous to Paleocene crystallization ages. CL images of zircon from both the CEMMA units and Magdalena granites that intrude them suggest that the Eocene dates are from analyses of high U (CL dark) zircon rims with elevated U/Th ratios (Figure 9). The similar age, geochemistry, and texture of these zircon domains suggest they crystallized contemporaneously from a common melt. The lack of microporous textures and mineral inclusions in the rims suggest they did not form by subsolidus diffusion-reaction processes mediated by aqueous fluids, sometimes called hydrothermal zircon formation (Tomaschek et al., 2003; Hoskin, 2005; Geisler et al., 2007; Schaltegger, 2007). In the Magdalena granites, we interpret the rims to have crystallized on inherited, xenocrystic zircon from CEMMA units that had been disaggregated-assimilated into the melt. In the CEMMA units, we interpret the rims to have crystallized on existing zircon phenocrysts from melt that had infiltrated into the rock. The high U/Th of the zircon rims is generally consistent with metamorphic zircon and this type of crystallization has been described as suprasolidus metamorphic zircon or anatectic zircon (Kohn et al., 2015; Rubatto, 2017; Yakymchuk et al., 2018).

Anatectic zircon growth is common in migmatites (cf. Yakymchuk, 2023) and we considered the possibility that the CEMMA units were themselves were melting to produce the Magdalena granites. However, we did not observe features characteristic of partial melting, including melt segregation structures, mafic selvages, and leucosome development. Although the CEMMA units can be deformed, mostly mylonitized, they are fundamentally igneous rocks that show no evidence of metamorphic or migmatitic fabric development during the intrusion of the Magdalena granites. Intrusive contacts between the leucocratic Magdalena granites and relatively melanocratic Cañada Honda granodiorite and the Sierra Madera syenogranite can be

irregularly shaped and diffuse or blurred with gradations in color index between the units (Figure 2f). These CEMMA units are also characterized by subtle leucocratic patches and feldspar disaggregation, giving the outcrop a spotted appearance (Figure 2f). These features are consistent with melt infiltration into a magmatic mush and incipient mush disaggregation (Weinberg et al., 2021) and can explain zircon rim growth in the CEMMA units (cf. Reichardt et al., 2010; Hasalová et al., 2011). Preexisting textures in the CEMMA units, including mylonitic fabrics, can be blurred, but not completely overprinted, resulting in ghost structures, which is a common feature of interstitial melt flow in mushes (cf. Hasalová et al., 2008; Weinberg et al., 2021).

The abundance of mush textures suggests that the CEMMA units (e.g., Cañada Honda granodiorite) were relatively hot when the Magdalena granite magmas intruded. The presence of magmatic epidote in the CEMMA units indicates they crystallized at pressures > 0.5 GPa, or > ~15 km depth (Zen and Hammarstrom, 1984; Schmidt and Poli, 2004) and the rocks may have remained at elevated temperatures between the time of crystallization (ca. 75–60 Ma) and the time of intrusion of the Magdalena granites (ca. 45–35 Ma). Alternatively, the CEMMA units may have been (re)heated by the anatectic event that produced the Magdalena granites. More work constraining the temperature and pressure history of the Magdalena granites and CEMMA units will help evaluate these models.

 

CONCLUSIONS

The Magdalena granites are a suite of Paleocene to Eocene age, variably mylonitized, high-silica (> 70 wt. % SiO2) granitoids that outcrop in the Magdalena-Tubutama region of northern Sonora, México. Moderately peraluminous two-mica granite and muscovite ± garnet-bearing leucogranite comprise the majority of lithologies and there are no extrusive equivalents. The Magdalena granites are part of the North American Cordilleran Anatectic Belt and intrude into Mesozoic age volcanic, plutonic and metasedimentary rocks primarily exposed in the footwall of metamorphic core complexes. Apart from two slightly older granites (ca. 60 Ma; Las Jarillas and Cañada Tescalama granites), weighted mean zircon 206Pb/238U ages for the Magdalena granites are between 38 and 51 Ma. Inherited, xenocrystic, zircon is common, but many individual samples also yield a wide range of zircon dates that may reflect more complex melting and crystallization processes. The Magdalena granites exhibit high zircon U/Th and bimodal date populations characteristic of many anatectic granites. The granites are generally younger than arc-related igneous rocks associated with CEMMA in northern Sonora; three new samples identified in this study range from 72 to 61 Ma in this study. Geochemically, the Magdalena granites are distinctive from CEMMA rocks and are relatively depleted in LREE and enriched in HREE, producing flat or concave up (excluding Eu) normalized REE patterns. Some Magdalena granites have experienced advanced fractional crystallization. Low LREE contents and negative P, Zr, and Hf anomalies suggest the crystallization and removal of accessory phases including monazite and zircon. Whole rock minor and trace element compositions are also consistent with fractionation of plagioclase and K-feldspar and some of the studied granites are cumulates. The compositions of the Magdalena granites are broadly consistent with water-absent muscovite- to biotite-dehydration melting of metasedimentary and metaigneous protoliths, but more work is needed to investigate melting conditions.

This study is among the first to present detailed geochronologic and geochemical data from Cenozoic age anatectic granites in northern México and helps to define a unique event in the tectonic evolution of the North American Cordillera. Relatively little is understood about the tectonic processes that produced crustal melting in this region. Still, the results are consistent with previous studies in the southern U.S. Cordillera hypothesizing the existence of an orogenic plateau during the Late Cretaceous to Paleogene that may have contributed to radiogenic heating. Field relationships indicate the Magdalena granites intruded into relatively hot crust, including host rock mushes, although there is no direct evidence for in situ melting (migmatization) of the rocks exposed in the study area. Whatever the reason for crustal melting, this study demonstrates that geology transcends international borders and that models developed for the U.S. must be able to explain observations and data from México, and vice versa.

 

SUPPLEMENTARY MATERIAL

Supplementary File S1: Petrographic summary and description of samples. File S2: Zircon U-Pb LA-ICPMS data. File S3: Zircon trace element LA-ICPMS data. File S4: Zircon U-Pb ID-TIMS data. File S5: ID-TIMS analytical methods. File S6: Whole rock geochemical data can be found on the Abstract’s preview page of this article. https://rmcg.geociencias.unam.mx/index.php/rmcg/article/view/1924

 

Acknowledgments. Constructive reviews by Martín Valencia-Moreno helped improve an earlier version of the manuscript. We thank Aimé Orcí-Romero at ERNO for sample preparation and thin sections. We also thank the many ranch owners and ejidatarios of the Magdalena-Tubutama region who kindly granted us permits to work on their land. Carlos Ortega-Obregón at Instituto de Geociencias, UNAM, is also thanked for maintaining the LA-ICPMS facilities and performing the U-Pb determinations. Lee Silver and Tom Anderson collected several key samples between 1970 and 1980 that served as the basis for later studies and Paul Asimow graciously provided access to Lee Silver’s archives at Caltech from which corresponding field descriptions, ID-TIMS analyses, and geochemical data were recovered.

Funding. C.M. González-León acknowledges support from CONACYT (presently Secretaría de Ciencia, Humanidades, Tecnología e Inovación, Gobierno de México) Project No. 253545. Chapman acknowledges support from U.S. National Science Foundation grants EAR-2344655 and EAR-2335771. Nourse acknowledges Lee Silver and Caltech for supporting his field studies between 1985 and 1989.

Author Contributions. James Chapman: data interpretation, visualization, writing, and revision. Carlos González-León: conceptualization, funding acquisition, field work, data collection, data interpretation, writing, and revision. Luigi Solari: methodology, sample analysis, data interpretation, revision. Elizard González: data interpretation, visualization, writing, and revision. Jonathan Nourse: field work, sample collection and analysis, data interpretation, writing, and revision. Michelle Vázquez: field work, data collection and analysis. Teresita Sánchez Navarro: field work, data collection and data interpretation. Rufino Lozano Santacruz: data collection and analysis. Ofelia Perez Arvizu: data collection and analysis. Estefany Grijalva Espinoza: field work, data collection and analysis.

Data availability statement. All data presented in the manuscript are fully available, either within this article or in the supplementary material.

Declaration of competing interests. The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work reported in this article. Luigi Solari is currently Editor-in-Chief of the Revista Mexicana de Ciencias Geológicas; however, he did not intervene in editorial handling or decisions regarding this manuscript.

 

REFERENCES

Almirudis-Echeverría, E. (2010). Petrogénesis y Geocronología 40Ar-39Ar del Plutonismo Laramídico del área Sobai Satechi, Sonora, México [B.Sc. Thesis]. Universidad de Sonora, Departamento de Geología, 87 pp.

Anders, E., & Grevesse, N., (1989). Abundances of the elements: Meteoritic and solar. Geochimica et Cosmochimica Acta, 53, 197–214.

Anderson, T. H., Rodriguez-Castaneda, J. L., & Silver, L. T. (2005). Jurassic rocks in Sonora, Mexico; relations to the Mojave-Sonora megashear and its inferred northwestward extension. In T.H., Anderson, et al. (Eds.), The Mojave-Sonora megashear hypothesis; development, assessment, and alternatives. Geological Society of America Special Paper, 393, 51–95. https://doi.org/10.1130/0-8137-2393-0.51.

Anderson, T. H., Silver, L. T., & Salas, G. A. (1980). Distribution and U‐Pb isotope ages of some lineated plutons, northwestern Mexico. In M. D., Crittenden, P. J., Coney, & G. H., Davis, Cordilleran Metamorphic Core Complexes. Geological Society of America Memoir, 153, 269–283.

Bahadori, A., & Holt, W. E. (2019). Geodynamic evolution of southwestern North America since the Late Eocene. Nature Communications, 10, 5213. https://doi.org/10.1038/s41467-019-12950-8.

Barker, F., 1979, Trondhjemite: definition, environment and hypotheses of origin. Developments in Petrology. Elsevier, 6, 1–12.

Barth, A. P., & Wooden, J. L. (2006). Timing of magmatism following initial convergence at a passive margin, southwestern U.S. Cordillera, and ages of lower crustal magma sources. The Journal of Geology, 114, 231–245. https://doi.org/10.1086/499573

Barth, A. P., Tosdal, R. M., & Wooden, J. L. (1990) A petrologic comparison of Triassic plutonism in the San Gabriel and Mule Mountains, southern California. Journal of Geophysical Research, 95, 20075–20096. https://doi.org/10.1029/JB095iB12p20075

Barth, A. P., Tosdal, R. M., Wooden, J. L., & Howard, K. A. (1997). Triassic plutonism in Southern California; southward younging of arc initiation along a truncated continental margin. Tectonics, 6, 290–304. https://doi.org/10.1029/96TC03596

Batchelor, R. A., & Bowden, P. (1985). Petrogenetic interpretation of granitoid rock series using multicationic parameters. Chemical Geology, 48, 43–55. https://doi.org/10.1016/0009-2541(85)90034-8

Bonin, B., Janoušek, V., & Moyen, J. F. (2020). Chemical variation, modal composition and classification of granitoids. Geological Society, London, Special Publications, 491, 9–51. https://doi.org/10.1144/SP491-2019-138

Busby, C. J., & Centeno-García, E. (2022). The “Nazas Arc” is a continental rift province: implications for Mesozoic tectonic reconstructions of the southwest Cordillera, U.S. and Mexico. Geosphere, 18. 647–669. https://doi.org/10.1130/GES02443.1

Busby-Spera, C. J. (1988). Speculative tectonic model for the early Mesozoic arc of the southwest Cordilleran United States. Geology, 16, 1121–1125. https://doi.org/10.1130/0091-7613(1988)016<1121:STMFTE>2.3.CO;2

Chapman, J. B., Dafov, M. N., Gehrels, G., Ducea, M. N., Valley, J. W., & Ishida, A. (2018). Lithospheric architecture and tectonic evolution of the southwestern U.S. Cordillera: Constraints from zircon Hf and O isotopic data. Geologic Society of America Bulletin, 130, 2031–2046. https://doi.org/10.1130/B31937.1

Chapman, J. B., Greig, R., & Haxel, G. B. (2019). Geochemical evidence for an orogenic plateau in the southern U.S. and northern Mexican Cordillera during the Laramide orogeny. Geology, 48, 164–168. https://doi.org/10.1130/G47117.1 Chapman, J.B., Fitz-Diaz, E., & Iriondo, A. (2025). Mistaken Identity: The Laramide orogen in the southwest U.S. is part of the Mexican Cordilleran Orogenic Wedge. In S.,Gordon, B., Tikoff, M., Rusmore, & R., Miller, Jurassic-Paleogene tectonic evolution of the North American Cordillera. Geological Society of America Special Paper, 565. DOI 10.1130/2025.2565(17)

Chapman, J. B., Runyon, S. E., Shields, J. E., Lawler, B. L., Pridmore, C. J., Scoggin, S. H., Swaim, N. T., Trzinski, A. E., Wiley, H. N., Barth, A. P., & Haxel, G. B. (2021). The North American Cordilleran Anatectic Belt. Earth-Science Reviews, 215, 103576. https://doi.org/10.1016/j.earscirev.2021.103576

Chapman, J.B., Pridmore, C., Chamberlain, K., Haxel, G., & Ducea, M. (2023). Himalayan-like crustal melting and differentiation in the southern North American Cordilleran anatectic belt during the Laramide orogeny: Coyote Mountains, Arizona. Journal of Petrology, 64, 1–22. https://doi.org/10.1093/petrology/egad075

Claiborne, L.L., Miller, C.F., Walker, B.A., Wooden, J.L., Mazdab, F.K., & Bea, F. (2006). Tracking magmatic processes through Zr/Hf ratios in rocks and Hf and Ti zoning in zircons: An example from the Spirit Mountain batholith, Nevada. Mineralogical Magazine, 70, 517–543. https://doi.org/10.1180/0026461067050348

Clark, K.F., Foster, C.T., & Damon, P.E. (1982). Cenozoic mineral deposits and subduction related magmatic arcs in Mexico. Geological Society of America Bulletin, 93, 533–544. https://doi.org/10.1130/0016-7606(1982)93<533:CMDASM>2.0.CO;2

Compañía Minera Cascabel, S.A. de C.V., 2000, Carta Geológico-Minera Santa Ana H12-A69, escala 1:50,000. Secretaría de Economía, Servicio Geológico Mexicano.

Coney, P.J. (1972) Cordilleran tectonics and North America plate motion. American Journal of Science, 272, 603–628. https://doi.org/10.2475/ajs.272.7.603

Coney, P.J., & Reynolds, S.J. (1977). Cordilleran Benioff zones. Nature, 270, 403–406. https://doi.org/10.1038/270403a0

Contreras-López, M., Delgado-Argote, L.A., Weber, B., Torres-Carrillo, X.G., Frei, D., Gómez-Alvarez, D.K., Tazzo-Rangel, M.D., & Schmitt, A.K. (2021). Geochemistry, UPb geochronology, and Sr-Nd-Hf isotope systematics of a SW-NE transect in the southern Peninsular Ranges batholith, Mexico: Cretaceous magmatism developed on a juvenile island-arc crust. Lithos, 400, 106375. https://doi.org/10.1016/j.lithos.2021.106375

Corral Gastélum, R., & Hernández Morales, P. (2008). Carta Geológico-Minera Santa Ana H12–B82: escala 1:50,000. Secretaría de Economía, Servicio Geológico Mexicano.

Cottle, J. M., Larson, K. P., & Yakymchuk, C. (2018). Contrasting accessory mineral behavior in minimum-temperature melts: Empirical constraints from the Himalayan metamorphic core. Lithos, 312, 57–71.

Damon, P. E., Clark, K. F., & Shafiqullah, M. (1983a). Geochronology of the porphyry copper deposits and related mineralization of Mexico. Canadian Journal of Earth Sciences, 20, 1052–1071. https://doi.org/10.1139/e83-095

Damon, P. E., Shafiqullah, M., Roldán-Quintana, J., & Cochemé, J. J. (1983b). El batolito Laramide (90–40 Ma) de Sonora (pp. 63–95). Asociación de Ingenieros de Minas, Metalugistas y Geólogos de México (AIMMGM), Memoria técnica XV.

Davis, G. H., Gardulski, A. F., & Anderson, T. H. (1981). Structural and structural-petrological characteristics of some metamorphic core complex terranes in southern Arizona and northern Sonora. In L., Ortlieb, & J., Roldan-Quintana (Eds.), Geology of Northwestern Mexico and Southern Arizona (pp. 323–363): Geological Society of America, Cordilleran Section Field Trip Guidebook,.

Davis, G.H., Spencer, J.E., & Gehrels, G.E. (2019). Field-trip guide to the Catalina–Rincon metamorphic core complex, Tucson. Arizona. In Pearthree, P.A. (Ed.) Geologic excursions in southwestern North America (1-38). Geological Society of America Field Guide, 55. https://doi.org/10.1130/2019.0055(01)

de la Roche, H. D., Leterrier, J. T., Grandclaude, P., & Marchal, M. (1980). A classification of volcanic and plutonic rocks using R1R2-diagram and major-element analyses - its relationships with current nomenclature. Chemical Geology, 29, 83–210. https://doi.org/10.1016/0009-2541(80)90020-0

Dickinson, W. R. (2004). Evolution of the North American Cordillera. Annual Review of Earth and Planetary Sciences, 32, 13–45. https://doi.org/10.1146/annurev.earth.32.101802.120257

Dickinson, W. R., & Lawton, T. F. (2001). Tectonic setting and sandstone petrofacies of the Bisbee basin (USA–Mexico). Journal of South American Earth Sciences, 14(5), 475–504. https://doi.org/10.1016/S0895-9811(01)00046-3

Ding, H., Zhang, Z., Kohn, M. J., & Gou, Z. (2021). Timescales of partial melting and melt crystallization in the eastern Himalayan orogen: insights from zircon petrochronology. Geochemistry, Geophysics, Geosystems, 22(4), e2020GC009539. https://doi.org/10.1029/2020GC009539

Escamilla Torres, T. R., & Guzmán Espinoza, J. B. (2008). Carta Geológico-Minera El Correo H12-A49. Secretaría de Economía, Servicio Geológico Mexicano.

Farina, F., Dini, A., Davies, J. H., Ovtcharova, M., Greber, N. D., Bouvier, A. S., Baumgartner, L., Ulianov, A., & Schaltegger, U. (2018). Zircon petrochronology reveals the timescale and mechanism of anatectic magma formation. Earth and Planetary Science Letters, 495, 213–223. https://doi.org/10.1016/j.epsl.2018.05.021

Farmer, G. L., & DePaolo, D. J. (1983). Origin of Mesozoic and Tertiary granite in the western United States and implications for Pre‐Mesozoic crustal structure: 1. Nd and Sr isotopic studies in the geocline of the Northern Great Basin. Journal of Geophysical Research: Solid Earth, 88, 3379–3401. https://doi.org/10.1029/JB088iB04p03379

Ferrari, L., Orozco-Esquivel, T., Bryan, S. E., Lopez-Martinez, M., & Silva-Fragoso, A. (2018). Cenozoic magmatism and extension in western Mexico: Linking the Sierra Madre Occidental silicic large igneous province and the Comondú Group with the Gulf of California rift. Earth-Science Reviews, 183, 115–152. https://doi.org/10.1016/j.earscirev.2017.04.006

Finger, F., & Schiller, D. (2012). Lead contents of S-type granites and their petrogenetic significance. Contributions to Mineralogy and Petrology, 164, 747–755. https://doi.org/10.1007/s00410-012-0771-3

Fitz-Díaz, E., Lawton, T. F., Juárez-Arriaga, E., & Chávez-Cabello, G. (2018). The Cretaceous-Paleogene Mexican orogen: Structure, basin development, magmatism and tectonics. Earth-Science Reviews, 183, 56–84. DOI: 10.1016/j.earscirev.2017.03.002

Frost, B. R., Barnes, C.G., Collins, W. J., Arculus, R. J., Ellis, D. J., & Frost, C. D. (2001). A geochemical classification for granitic rocks. Journal of Petrology, 42, 2033–2048.

Gehrels, G., Rusmore, M., Woodsworth, G., Crawford, M., Andronicos, C., Hollister, L., Patchett, J., Ducea, M., Butler, R., Klepeis, K., & Davidson, C. (2009). U-Th-Pb geochronology of the Coast Mountains batholith in north-coastal British Columbia: Constraints on age and tectonic evolution. Geological Society of America Bulletin, 121, 1341–1361.

Geisler, T., Schaltegger, U., & Tomaschek, F. (2007). Re-equilibration of zircon in aqueous fluids and melts. Elements, 3(1), 43–50, https://doi.org/10.2113/gselements.3.1.43

Gómez-Valencia, A. M., Barrón-Díaz, A. J., Espinoza-Encinas, I. R., Lozano-Santa Cruz, R., Iriondo, A., Paz-Moreno, F. A., & Vidal-Solano, J. R. (2022). Petrogenesis and geodynamic implications of the Late Cretaceous granitoids in Puerto Libertad, Sonora, México: Insights into geochemical signatures of adakites, adakitic affinity and calc-alkaline rocks in NW Mexico. Journal of South American Earth Sciences, 119, 103996. https://doi.org/10.1016/j.jsames.2022.103996

González-Becuar, E., Pérez-Segura, E., Vega-Granillo, R., Solari, L., González-León, C.M., Solé, J., & López Martínez, M. (2017). Laramide to Miocene syn-extensional plutonism in the Puerta del Sol area, central Sonora, Mexico. Revista Mexicana de Ciencias Geológicas, 34, 45–61. https://doi.org/10.22201/cgeo.20072902e.2017.1.401

González-León, C. M., & Moreno-Hurtado, G. S. (2021). Mapa geológico y base de datos geocronológicos de Sonora, México. Terra Digitalis, 5(1), 1–7. DOI: 10.22201/igg.25940694e.2021.1.76

González-León, C. M., McIntosh, W. C., Lozano-Santacruz, R., Valencia-Moreno, M., Amaya-Martínez, M., & Rodríguez-Castañeda, J. L. (2000). Cretaceous and Tertiary sedimentary, magmatic, and tectonic evolution of north-central Sonora (Arizpe and Bacanuchi quadrangles), northwest Mexico. Geological Society of America Bulletin, 112, 600–610. https://doi.org/10.1130/0016-7606(2000)112<600:CATSMA>2.0.CO;2

González-León, C.M., Solari, L., Solé, J., Ducea, M.N., Lawton, T. F., Bernal, J. P., González Becuar, E., Gray, F., López Martínez, M., & Lozano Santacruz, R. L. (2011). Stratigraphy, geochronology, and geochemistry of the Laramide magmatic arc in north-central Sonora, Mexico. Geosphere, 7, 1392–1418. https://doi.org/10.1130/GES00679.1

González-León, C.M., Solari, L., Valencia-Moreno, M., Heimpel, M.A.R., Solé, J., González Becuar, E.g., Lozano Santacruz, R.L., & Pérez Arvizu, O. (2017). Late Cretaceous to early Eocene magmatic evolution of the Laramide arc in the Nacozari quadrangle, northeastern Sonora, Mexico and its regional implications. Ore Geology Reviews, 81, 1137–1157. https://doi.org/10.1016/j.oregeorev.2016.07.020

González-León, C. M., Madhavaraju, J., Montoya, E. R., Solari, L. A., Villanueva-Amadoz, U., Monreal, R. & Medrano, P. S. (2020). Stratigraphy, detrital zircón geochronology and provenance of the Morita formation (Bisbee Group) in northeastern Sonora, Mexico. Journal of South American Earth Sciences, 103, 102761. https://doi.org/10.1016/j.jsames.2020.102761

González-León, C.M., Vázquez-Salazar, M., Sánchez-Navarro, T., Solari, L.A., Nourse, J.A., Del Rio-Salas, R., Lozano-Santacruz, R., Pérez Arvizu, O., & Valenzuela Chacon, J.C.V. (2021). Geology and geochronology of the Jurassic magmatic arc in the Magdalena quadrangle, north-central Sonora, Mexico. Journal of South American Earth Sciences, 108, 103055. https://doi.org/10.1016/j.jsames.2020.103055

Grijalva Espinoza, E. G. (2023). Geocronología y geoquímica del granito Tubutama, área de Tubutama, norte de Sonora [Bachelor thesis]. Universidad Estatal de Sonora, Unidad Académica Magdalena.

Harris, N. B. W., & Inger, S. (1992). Trace element modelling of pelite-derived granites. Contributions to Mineralogy and Petrology, 110, 46–56. https://doi.org/10.1007/BF00310881

Hasalová, P., Stipská, P., Powell, R., Schulmann, K., Janousek, V., & Lexa, O. (2008). Transforming mylonitic metagranite by open-system interactions during melt flow. Journal of Metamorphic Geology, 26, 55–80. DOI: 10.1111/j.1525-1314.2007.00744.x

Hasalová, P., Weinberg, R. F., & MacRae, C. (2011). Microstructural evidence for magma confluence and reusage of magma pathways: implications for magma hybridization, Karakoram Shear Zone in NW India. Journal of Metamorphic Geology, 29, 875–900. https://doi.org/10.1111/j.1525-1314.2011.00945.x

Haxel, G. B., Tosdal, R. M., May, D. J., & Wright, J. E. (1984). Latest Cretaceous and early Tertiary orogenesis in south-central Arizona: Thrust faulting, regional metamorphism, and granitic plutonism. Geological Society of America Bulletin, 95, 631–653. https://doi.org/10.1130/0016-7606(1984)95<631:LCAETO>2.0.CO;2

Haxel, G. B., May, D. J., Anderson, T. H., Tosdal, R. M., & Wright, J. E. (2008). Geology and geochemistry of Jurassic plutonic rocks, Baboquivari Mountains, south-central Arizona. In J. E., Spencer, S. R., Titley (Eds.), Ores and Orogenesis: Circum-Pacific Tectonics, Geologic Evolution and Ore Deposits. Arizona Geological Society Digest, 22, 497–515.

Haxel, G. B., Johnson, D. A., Briskey, J. A., Tosdal, R. M., & Wright, J. E. (2022). Ore and other metals in Laramide metaluminous and peraluminous granitoids, and in the upper crust, south-central Arizona and north-central Sonora. Arizona Geological Survey Contributed Report CR-22-D, 45 pp.

Herrera Urbina, S., Valencia, V., Paz Moreno, F. A., Gehrels, G., & García Salido, R. (2006). Plutonismo hiperaluminoso asociado al “metamorphic core complex” de Magdalena, Sonora norte-central, Mexico. Boletín Informativo de la Unión Geofísica Mexicana, GEOS, 26, 98-99.

Hoskin, P. W., 2005. Trace-element composition of hydrothermal zircon and the alteration of Hadean zircon from the Jack Hills, Australia. Geochimica et cosmochimica acta, 69(3), 637–648. https://doi.org/10.1016/j.gca.2004.07.006

Hoskin, P. W. O., & Schaltegger, U. (2003). The composition of zircon and igneous and metamorphic petrogenesis. In Hanchar, J. M., & Hoskin, P. W. O. (Eds.), Zircon. Reviews in Mineralogy and Geochemistry, 53, 27–62. https://doi.org/10.2113/0530027

Inger, S., & Harris, N. (1993). Geochemical constraints on leucogranite magmatism in the Langtang Valley, Nepal Himalaya. Journal of Petrology, 34(2), 345–368. https://doi.org/10.1093/petrology/34.2.345

Iriondo, A., Arvizu, H. E., Paz-Moreno, F. A., Izaguirre, A., Velázquez-Santalíz, A. F., Velasco-Tapia, F., Martínez-Torres, L. M., Pérez-Arvizu, O., & Lozano-Santa Cruz, R. (2022). Major and trace element geochemistry of Permo-Triassic granitoids from NW Sonora, Mexico: Constraints on the origin of the Late Paleozoic-early Mesozoic Cordilleran magmatic arc along SW Laurentia. Applied Geochemistry, 143, 105359. https://doi.org/10.1016/j.apgeochem.2022.105359

Ji, M., Gao, X. Y., & Zheng, Y. F. (2022). Geochemical evidence for partial melting of progressively varied crustal sources for leucogranites during the Oligocene–Miocene in the Himalayan orogen. Chemical Geology, 589, 120674. https://doi.org/10.1016/j.chemgeo.2021.120674

Kelsey, D. E., & Powell, R. (2011). Progress in linking accessory mineral growth and breakdown to major mineral evolution in metamorphic rocks: A thermodynamic approach in the Na2O‐CaO‐K2O‐FeO‐MgO‐Al2O3‐SiO2‐H2O‐TiO2‐ZrO2 system. Journal of Metamorphic Geology, 29, 151–166. https://doi.org/10.1111/j.1525-1314.2010.00910.x

Kimbrough, D. L., Grove, M., & Morton, D. M. (2015). Timing and significance of gabbro emplacement within two distinct plutonic domains of the Peninsular Ranges batholith, southern and Baja California. Geological Society of America Bulletin, 127(1-2), 19–37. https://doi.org/10.1130/B30914.1

Kirkland, C. L., Smithies, R. H., Taylor, R. J. M., Evans, N., & McDonald, B. (2015). Zircon Th/U ratios in magmatic environs. Lithos, 212, 397–414. https://doi.org/10.1016/j.lithos.2014.11.021

Kohn, M. J., Corrie, S. L., & Markley, C., 2015, The fall and rise of metamorphic zircon. American Mineralogist, 100, 897–908. https://doi.org/10.2138/am-2015-5064

Kylander-Clark, A. R. C., Hacker, B. R., & Cottle, J. M. (2013). Laser-ablation split-stream ICP petrochronology. Chemical Geology, 345, 99–112. https://doi.org/10.1016/j.chemgeo.2013.02.019

Lawton, T. F., Amato, J. M., Machin, S. E., Gilbert, J. C., & Lucas, S. G. (2020). Transition from Late Jurassic rifting to middle Cretaceous dynamic foreland, southwestern U.S. and northwestern Mexico. Geological Society of America Bulletin, 132(11-12), 2489–2516. https://doi.org/10.1130/B35433.1

Lederer, G. W., Cottle, J. M., Jessup, M. J., Langille, J. M., & Ahmad, T. (2013). Timescales of partial melting in the Himalayan middle crust: insight from the Leo Pargil dome, northwest India. Contributions to Mineralogy and Petrology, 166(5), 1415–1441. https://doi.org/10.1007/s00410-013-0935-9

Lee, D. E., Kistler, R. W., Friedman, I., & Van Loenen, R. E. (1981). Two‐mica granites of northeastern Nevada. Journal of Geophysical Research: Solid Earth, 86(B11), 10607–10616. https://doi.org/10.1029/JB086iB11p10607

Lee, S. Y., Barnes, C. G., Snoke, A. W., Howard, K. A. & Frost, C. D. (2003). Petrogenesis of Mesozoic, peraluminous granites in the Lamoille Canyon area, Ruby Mountains, Nevada, USA. Journal of Petrology, 44(4), 713–732. https://doi.org/10.1093/petrology/44.4.713

Liu, L., Gurnis, M., Seton, M., Saleeby, J., Müller, R. D. & Jackson, J. M. (2010). The role of oceanic plateau subduction in the Laramide orogeny. Nature Geoscience, 3, 353–357. https://doi.org/10.1038/ngeo829

Liu, Z. C., Wu, F. Y., Liu, X. C., Wang, J. G., Yin, R., Qiu, Z. L., Ji, W. Q., & Yang, L. (2019). Mineralogical evidence for fractionation processes in the Himalayan leucogranites of the Ramba Dome, southern Tibet. Lithos, 340, 71–86. https://doi.org/10.1016/j.lithos.2019.05.004

Macías-Valdez, G. (1992). Geoquímica (elementos mayores, trazas y tierras raras) del Granito de Huépac (Sonora), implicaciones petrogenéticas y tectónicas [Bachelor tesis]. Universidad de Sonora, Departamento de Geología.

McDowell, F. W., Roldán-Quintana, J., & Amaya-Martínez, R. (1997). Interrelationship of sedimentary and volcanic deposits associated with Tertiary extension in Sonora, Mexico. Geological Society of America Bulletin, 109, 1349–1360. https://doi.org/10.1130/0016-7606(1997)109<1349:IOSAVD>2.3.CO;2

McDowell, F. W., Roldán-Quintana, J., & Connelly, J. N. (2001). Duration of Late Cretaceous– early Tertiary magmatism in east-central Sonora, Mexico. Geological Society of America Bulletin, 113, 521–531. https://doi.org/10.1130/0016-7606(2001)113<0521:DOLCET>2.0.CO;2

Miller, C. F., & Barton, M. D. (1990). Phanerozoic plutonism in the Cordilleran interior, USA. In S. M., Kay, & C. W., Rapela (Eds.), Plutonism from Antarctica to Alaska. Geological Society of America Special Paper, 241, 213–231.

Miller, C. F., & Bradfish, L. J. (1980). An inner Cordilleran belt of muscovite-bearing plutons. Geology, 8, 412–416. https://doi.org/10.1130/0091-7613(1980)8<C412:AICBOM>2.0.CO;2

Moreno Ibarra, V. M., & Martínez Cuevas, F. (2019). Carta Geológico-Minera El Carrizo H12-A59, escala 1:50,000. Secretaría de Economía, Servicio Geológico Mexicano.

Mori, L., Gómez-Tuena, A., Cai, Y., & Goldstein, S. L. (2007). Effects of prolonged flat subduction on the Miocene magmatic record of the central Trans-Mexican Volcanic Belt. Chemical Geology, 244, 452–473. https://doi.org/10.1016/j.chemgeo.2007.07.002

Nourse, J. A. (1989). Geological evolution of two crustal scale shear zones: Part I. The Rand thrust complex, northwestern Mojave Desert, California. Part II. The Magdalena metamorphic core complex, north central Sonora, Mexico [Ph.D. dissertation]. California Institute of Technology, 394 pp.

Nourse, J. A. (1990). Tectonostratigraphic Development and Strain History of the Magdalena Metamorphic Core Complex, Northern Sonora, Mexico. In G. E. Gehrels, & J. E. Spencer (Eds.), Geologic excursions through the Sonoran Desert region, Arizona and Sonora. Arizona Geological Survey Special Paper, 7, 155–164.

Nourse, J. A., Anderson, T. H., & Silver, L. T. (1994). Tertiary metamorphic core complexes in Sonora, northwestern Mexico. Tectonics, 13, 1161–1182. https://doi.org/10.1029/93TC03324

Nourse, J. A., Jacques-Ayala, C., González-León, C. M., & Roldan-Quintana, J. (1995). Jurassic-Cretaceous paleogeography of the Magdalena region, northern Sonora, and its influence on the positioning of Tertiary metamorphic core complexes. In C., Jacques-Ayala, C. M.,Gonzalez-Leon, & J., Roldan-Quintana (Eds.) Studies on the Mesozoic of Sonora and adjacent areas: Geological Society of America Special Paper, 301, 59–78.

Nourse, J. A., González-León, C. M., Solari, L., Zapata-Martínez, J. A., & Premo, W. R. (2018). New U-Pb zircon analyses record Paleocene and mid Eocene-early Oligocene melting of Late Cretaceous, Jurassic, and Proterozoic crust in lower plate of the Magdalena-Madera metamorphic core complex, Sonora, Mexico. Geological Society of America Abstracts with Programs, 50. DOI 10.1130/abs/2018RM-313963.

Patiño-Douce, A. E. (1999). What do experiments tell us about the relative contributions of crust and mantle to the origin of granitic magmas?. Geological Society, London, Special Publication, 168, 55–75.

Patiño-Douce, A. E., Humphreys, E. D., & Johnston, A. D. (1990). Anatexis and metamorphism in tectonically thickened continental crust exemplified by the Sevier hinterland, western North America. Earth and Planetary Science Letters, 97, 290–315. https://doi.org/10.1016/0012-821X(90)90048-3

Paton, C., Hellstrom, J., Paul, B., Woodhead, J., & Hergt, J. (2011). Iolite: Freeware for the visualisation and processing of mass spectrometric data: Journal of Analytical Atomic Spectrometry, 26, 2508–2518. https://doi.org/10.1039/C1JA10172B

Pérez-Segura, E., González-Partida, E., & Valencia, V. (2009). Late Cretaceous adakitic magmatism in east-central Sonora, Mexico, and its relation to Cu-Zn-Ni-Co skarns. Revista Mexicana de Ciencias Geológicas, 26, 411–427.

Peryam, T. C., Lawton, T. F., Amato, J. M., González-León, C. M., & Mauel, D. J. (2012). Lower Cretaceous strata of the Sonora Bisbee Basin: A record of the tectonomagmatic evolution of northwestern Mexico. Geological Society of American Bulletin, 124, 532–548. https://doi.org/10.1130/B30456.1

Pineda, C., Schmitt, A. K., & Morata, D. (2022). Monazite as a control on Th/U in magmatic zircon. Chemical Geology, 603, 120911. https://doi.org/10.1016/j.chemgeo.2022.120911

Prince, C., Harris, N., & Vance, D. (2001). Fluid-enhanced melting during prograde metamorphism. Journal of the Geological Society, 158(2), 233–241. https://doi.org/10.1144/jgs.158.2.233

Ramírez López, J. A., Maldonado Cancio, A. J., & Castro Escárrega, J. J. (2018). Carta Geológico-Minera Imuris H12-B51, escala 1:50, 000. Secretaría de Economía, Servicio Geológico Mexicano.

Reichardt, H., Weinberg, R. F., Andersson, U. B., & Fanning, M. C. (2010). Hybridization of granitic magmas in the source: the origin of the Karakoram Batholith, Ladakh, NW India. Lithos, 116, 249–272. DOI 10.1016/j.lithos.2009.11.013

Roldán-Quintana, J. (1991). Geology and chemical composition of the Jaralito and Aconchi batholiths in east-central Sonora, Mexico. In E. Pérez-Segura, C., Jaques-Ayala (Eds.), Studies of Sonoran Geology. Geological Society of America, Special Paper, 254, 69–80. https://doi.org/10.1130/SPE254-p69

Roldán-Quintana, J., McDowell, F. W., Delgado-Granados, H., & Valencia-Moreno, M. (2009). East-west variations in age, chemical and isotopic composition of the Laramide batholith in southern Sonora, Mexico. Revista Mexicana de Ciencias Geológicas, 26, 543–563.

Rubatto, D. (2017). Zircon: The metamorphic mineral. Reviews in Mineralogy and Geochemistry, 83(1), 261–295, https://doi.org/10.2138/rmg.2017.83.9

Rudnick, R. L. (1992). Restites, Eu anomalies and the lower continental crust. Geochimica et Cosmochimica Acta, 56(3), 963–970. https://doi.org/10.1016/0016-7037(92)90040-P

Salas, G. A. (1968). Areal geology and petrology of the igneous rocks of the Santa Ana region, Northwest Sonora. Boletín de la Sociedad Geológica Mexicana, 31, 11–63.

Sánchez-Navarro, T. (2018). Geología y Geocronología de las sierras El Álamo Viejo y Los Chinos, región de Tubutama, norte de Sonora [Tesis de licenciatura]. Universidad de Sonora, Departamento de Geología, 66 pp.

Sánchez Navarro, T., Vázquez Salazar, M., González-León, C. M., Solari, L. A., Egger, A. E., Orozco-Esquivel, T., López-Martínez, M., Nourse, J. A. Pérez Arvizu, O., & Lozano-Santacruz, R. (2025). Geology and geochronology of the Magdalena-Madera metamorphic core complex lower plate in the sierras Las Jarillas-El Potrero, northern Sonora. Revista Mexicana de Ciencias Geológicas, 42(2), 93–112. https://dx.doi.org/10.22201/igc.20072902e.2025.2.1838

Santillana Villa, C., Valencia-Moreno, M., Ochoa-Landín, L., & Del Río-Salas, R. (2022). Firmas de REE en intrusivos asociados a pórfidos de cobre en Sonora. Epistemus, 15. DOI 10.36790/epistemus.v15i31.188.

Scaillet, B., Pichavant, M., & Roux, J. (1995). Experimental crystallization of leucogranite magmas. Journal of Petrology, 36, 663–705. https://doi.org/10.1093/petrology/36.3.663

Schaltegger, U. (2007). Hydrothermal zircon. Elements, 3(1), 51–79. https://doi.org/10.2113/gselements.3.1.51

Schmidt, M. W., & Poli, S. (2004). Magmatic epidote. Reviews in Mineralogy and Geochemistry, 56(1), 399–430. DOI: 10.2138/gsrmg.56.1.399

Schwartz, J. J., Lackey, J. S., Miranda, E. A., Klepeis, K. A., Mora-Klepeis, G., Robles, F., & Bixler, J. D. (2023). Magmatic surge requires two-stage model for the Laramide orogeny. Nature Communications, 14, 3841. https://doi.org/10.1038/s41467-023-39473-7

Silver, L. T., & Chappell, B. W. (1988). The Peninsular Ranges Batholith: an insight into the evolution of the Cordilleran batholiths of southwestern North America. Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 79(2-3), 105–121. doi:10.1017/S0263593300014152

Sláma, J., Košler, J., Condon, D. J., Crowley, J. L., Gerdes, A., Hanchar, J. M., Horstwood, M. S., Morris, G. A., Nasdala, L., Norberg, N., & Schaltegger, U. (2008). Plešovice zircon – a new natural reference material for U–Pb and Hf isotopic microanalysis. Chemical Geology, 249, 1–35. https://doi.org/10.1016/j.chemgeo.2007.11.005

Solari, L. A., González-León, C. M., Ortega-Obregón, C., Valencia-Moreno, M., & Rascón-Heimpel, M. A. (2018). The Proterozoic of NW Mexico revisited: U–Pb geochronology and Hf isotopes of Sonoran rocks and their tectonic implications. International Journal of Earth Sciences, 107, 845–861. https://doi.org/10.1007/s00531-017-1517-2

Sun, S. S., & McDonough, W. F. (1989). Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. Geological Society, London, Special Publications, 42, 313–345. 10.1144/gsl.sp.1989.042.01.19

Tomaschek, F., Kennedy, A.K., Villa, I.M., Lagos, M., & Ballhaus, C. (2003). Zircons from Syros, Cyclades, Greece—recrystallization and mobilization of zircon during high-pressure metamorphism. Journal of Petrology, 44(11), 1977–2002. https://doi.org/10.1093/petrology/egg067

Valencia-Moreno, M., Ruiz, J., Barton, M. D., Patchett, P. J., Zürcher, L., Hodkinson, D. G., & Roldán-Quintana, J. (2001). A chemical and isotopic study of the Laramide granitic belt of northwestern Mexico: Identification of the southern edge of the North American Precambrian basement. Geological Society of America Bulletin, 113, 1409–1422. https://doi.org/10.1130/0016-7606(2001)113<1409:ACAISO>2.0.CO;2

Valencia-Moreno, M., Ruiz, J., Ochoa-Landm, L., Martínez-Serrano, R., & Vargas-Navarro, P. (2003). Geochemistry of the coastal Sonora batholith, northwestern Mexico. Canadian Journal of Earth Sciences, 40(6), 819–831. https://doi.org/10.1139/e03-020

Valencia-Moreno, M., López-Martínez, M., Orozco-Esquivel, T., Ferrari, L., Calmus, T., Noury, M., & Mendívil-Quijada, H. (2021). The Cretaceous-Eocene Mexican Magmatic Arc: Conceptual framework from geochemical and geochronological data of plutonic rocks. Earth-Science Reviews, 220, 103721. https://doi.org/10.1016/j.earscirev.2021.103721

Vázquez Salazar, M. (2018). Geología de las sierras Las Jarillas y El Potrero, región de Santa Ana, norte de Sonora [Bachelor thesis]. Universidad Estatal de Sonora, Ingeniería en Geociencias.

Vermeesch, P. (2018). IsoplotR: A free and open toolbox for geochronology. Geoscience Frontiers, 9(5), 1479–1493. https://doi.org/10.1016/j.gsf.2018.04.001

Vidal Marian, M.A. (2023). Estudio cartográfico, petrográfico y geoquímico del sector centro-oeste del Batolito Laramide Hermosillo, norte de la ciudad de Hermosillo, Sonora, México [B.Sc. Thesis]. Universidad de Sonora, Departamento de Geología.

Weil, A.B., & Yonkee, A. (2023). The Laramide orogeny: Current understanding of the structural style, timing, and spatial distribution of the classic foreland thick-skinned tectonic system. In S.J., Whitmeyer, M.L., Williams, D.A., Kellett, & B., Tikoff, (Eds.), Laurentia: Turning Points in the Evolution of a Continent. Geological Society of America Memoir, 220, 707–771.

Weinberg, R. F. (2016). Himalayan leucogranites and migmatites: nature, timing and duration of anatexis. Journal of Metamorphic Geology, 34(8), 821–843. https://doi.org/10.1111/jmg.12204

Weinberg, R. F. & Hasalová, P. (2015). Water-fluxed melting of the continental crust: A review. Lithos, 212–215, 158–188. https://doi.org/10.1016/j.lithos.2014.08.021

Weinberg, R.F., Vernon, R.H.. & Schmeling, H. (2021). Processes in mushes and their role in the differentiation of granitic rocks. Earth-Science Reviews, 220, 103665, https://doi.org/10.1016/j.earscirev.2021.103665

Whitmeyer, S. J., & Karlstrom, K. E. (2007). Tectonic model for the Proterozoic growth of North America. Geosphere, 3, 220–259. https://doi.org/10.1130/GES00055.1

Wiedenbeck, M. A. P. C., Alle, P., Corfu, F. Y., Griffin, W. L., Meier, M., Oberli, F. V., Quadt, A. V., Roddick, J. C., & Spiegel, W. (1995). Three natural zircon standards for U‐Th‐Pb, Lu‐Hf, trace element and REE analyses. Geostandards newsletter, 19, 1–23. https://doi.org/10.1111/j.1751-908X.1995.tb00147.x

Wodzicki, W. A. (1995). The evolution of Laramide igneous rocks and porphyry copper mineralization in the Cananea district, Sonora, Mexico [PhD dissertation]. University of Arizona.

Wong, M. S., Gans, P. B., & Scheier, J. (2010). The 40Ar/39Ar thermochronology of core complexes and other basement rocks in Sonora, Mexico: Implications for Cenozoic tectonic evolution of northwestern Mexico. Journal of Geophysical Research: Solid Earth, 115(B7), B07414. https://doi.org/10.1029/2009JB007032

Wright, J. E., & Wooden, J. L. (1991). New Sr, Nd, and Pb isotopic data from plutons in the northern Great Basin: Implications for crustal structure and granite petrogenesis in the hinterland of the Sevier thrust belt. Geology, 19(5), 457–460. https://doi.org/10.1130/0091-7613(1991)019<C0457:NSNAPI>2.3.CO;2

Wu, F. Y., Liu, X. C., Liu, Z. C., Wang, R. C., Xie, L., Wang, J. M., Ji, W. Q., Yang, L., Liu, C., Khanal, G. P., & He, S. X. (2020). Highly fractionated Himalayan leucogranites and associated rare-metal mineralization. Lithos, 352, 105319. https://doi.org/10.1016/j.lithos.2019.105319

Yakymchuk, C. (2023). Prograde zircon growth in migmatites. Journal of Metamorphic Geology, 41(5), 719–743, https://doi.org/10.1111/jmg.12715

Yakymchuk, C., Clark, C., & White, R.W. (2017). Phase relations, reaction sequences and petrochronology. Reviews in Mineralogy and Geochemistry, 83, 13–53. https://doi.org/10.2138/rmg.2017.83.2

Yakymchuk, C., Kirkland, C. L., & Clark, C. (2018). Th/U ratios in metamorphic zircon. Journal of Metamorphic Geology, 36, 715–737. https://doi.org/10.1111/jmg.12307

Yang, L., Miller, C. F., Wang, J. M., Liu, X. C. & Wu, F. Y. (2025). Identification of fractionation processes in the Himalayan leucogranites-Case study from the Nyalam region. Lithos, 492, 107876. https://doi.org/10.1016/j.lithos.2024.107876

Zen, E. A., & Hammarstrom, J. M. (1984). Magmatic epidote and its petrologic significance. Geology, 12(9), 515–518. https://doi.org/10.1130/0091-7613(1984)12<515:MEAIPS>2.0.CO;2

Zeng, L., Gao, L. E., Tang, S., Hou, K., Guo, C., & Hu, G. (2015). Eocene magmatism in the Tethyan Himalaya, southern Tibet. Geological Society, London, Special Publications, 412, 287–316. https://doi.org/10.1144/SP412.8