Mapping Soil Geochemical Anomalies in the Mesa Quadrangle, Arizona, Using NURE Data

Abstract

Maps showing anomalously high concentrations of 13 different elements in soils within the Mesa Quadrangle of southern Arizona were constructed using information contained in the National Uranium Resource Evaluation (NURE) database. Existing geochemical databases such as NURE provide an inexpensive and accessible resource that can be used to characterize an area geochemically. Anomalies in soils were determined after applying descriptive statistics, logarithmic transformations, elimination of outliers, and manipulation of below‐limit detection values. Among the elements with the most number of anomalies, Cu clustered in the southcentral part of the quadrangle where porphyry copper deposits are located, while As, Be, Co, Cr, Zn, Th, and U anomalies were located over exposed Precambrian and Tertiary igneous rocks. In general, anomalies could be related to the rocks cropping out, type of soils, and several mines present in the area.

Geochemical processes contributing to the contamination of soil and surface waters in the Rio Conchos basin, Mexico

“…National geochemical databases consisting of chemical composition of a grid of samples became available to the U.S. in 1994 (Hoffman et al, 1994) and in Chihuahua, Mexico, in 2001(SGM, 2001. Although these databases were originally intended for geochemical exploration purposes, they were later found to provide an inexpensive and accessible information source for conducting geochemical characterization (Borrego and Gutiérrez, 2000;Xuejing and Hangxin, 2001). Within the Rio Conchos basin, sediment geochemistry and geospatial (GIS, remote sensing) studies are just as scarce as those of water quality.…”

Selected Heavy Metals as Indices of Atmospheric Pollution in African Locust Bean (<i>Parkia biglobosa</i>) Tree Barks

“…This is because industrial operations involving the separation of metals from gangues such as iron from iron ore, through heating and smelting produces very large amount of particulate metals and other air pollutants (OECD, 1990). Ferrous and nonferrous smelters for instance, emit large quantity of arsenic, lead, cadmium and other heavy metals into the environment, except where highly efficient pollution control equipment are used (Borrego, 1998;Pacyna and Pacyna, 2001;Vaisman and Lacerda, 2003). Nriagu (1989) reported that, the smelting of copper and other nonferrous metals, release an estimated six million tons of sulphur dioxide (SO 2 ) into the atmosphere each year, which sums up to about 8% of total worldwide emissions.…”