A multi-elemental study to establish the natural background and geochemical anomalies in rocks from the Sonora river upper basin, NW Mexico

  • Thierry Calmus Estación Regional del Noroeste, Instituto de Geología, Universidad Nacional Autónoma de Mexico, L.D. Colosio y Madrid S/N, Col. Los Arcos, Hermosillo, Sonora, 83240, Mexico.
  • Martín Valencia-Moreno Estación Regional del Noroeste, Instituto de Geología, Universidad Nacional Autónoma de Mexico, L.D. Colosio y Madrid S/N, Col. Los Arcos, Hermosillo, Sonora, 83240, Mexico.
  • Rafael Del Río-Salas Estación Regional del Noroeste, Instituto de Geología, Universidad Nacional Autónoma de Mexico, L.D. Colosio y Madrid S/N, Col. Los Arcos, Hermosillo, Sonora, 83240, Mexico.
  • Lucas Ochoa-Landín Departamento de Geología, Universidad de Sonora, Blvd. Luis Encinas y Rosales S/N, Col. Centro, Hermosillo, Sonora, 83000, Mexico.
  • Héctor Mendivil-Quijada GEO Digital Imaging de México, S.A. de C.V., Avenida Dr. Paliza 94, Col. Centenario, Hermosillo, Sonora, 83260, Mexico.
Keywords: geochemical background, conservative reference elements, Sonora river upper basin, mining district, Mexico

Abstract

Growing industrialization, including mining activity, dramatically increases environmental pollution. Exploitation of natural resources triggers landscape alteration, inputs of potentially toxic chemical elements to the environment and health diseases. In the case of mining activity, the measure of any associated environmental disturbance requires a geochemical background as a reference frame. Since in Mexico, there is a lack of this type of references in mining districts, the present study took a recent mining spill as an opportunity to establish the geochemical background of the upper Sonora river basin, which includes active and historical mining areas. The weighted average of elemental values was calculated using GIS tools. The data show that rocks have a similar geochemical behavior, which is characterized by pristine enrichment of Mn, Ca, P, Ba, Zn, As, Ag, Sb, W, Pb and Bi relative to the upper continental crust. Coefficients of variation values reveal that Sc, Y, Zr, Ce, Yb, Fe, Ti and Al display a conservative behavior and, therefore, they are recommended to be used as reference elements in environmental studies in the basin. The findings of this work highlight the need of determining the geochemical background in mining regions to reach more realistic environmental assessments.

Author Biography

Rafael Del Río-Salas, Estación Regional del Noroeste, Instituto de Geología, Universidad Nacional Autónoma de Mexico, L.D. Colosio y Madrid S/N, Col. Los Arcos, Hermosillo, Sonora, 83240, Mexico.

Estación Regional del Noroeste,
Instituto de Geología

Published
2018-07-25
Section
Articles