Geochemical characterization of mineral dust sources in the Chihuahuan Desert and southern High Plains regions
The Chihuahuan Desert (northern Chihuahua, southern New Mexico, and far west Texas) and the southern High Plains (west Texas and eastern New Mexico) regions have been identified as one of the most persistent dust producing regions of North America. Regional-scale dust storms have been observed by satellite imagery to identify sources of dust, resulting in collection and examination of physical soil samples to better understand the source signatures (geochemical characteristics) of dust origins in these two regions. The soil characteristics were examined through several techniques: Particle Size Distribution, X-Ray Diffraction (XRD), Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), and Total Organic Carbon. Numerous ordination analysis techniques were applied to the data. These results were used to interpret associations between elemental, mineral, and geological content on the dust-producing soil samples and the associated dust emission "hotspots" in the Chihuahuan Desert and Southern High Plains regions, and develop a database of the geochemical and physical attributes of dust producing soils in these adjacent regions. Granulometric data emphasized that dust source soils from the Chihuahuan Desert were less sandy textured when compared to those soil samples from the Southern High Plains region. Potassium, iron, aluminum, and titanium concentrations showed strong connectivity to anthropogenic activity (land use for farming). A cluster of samples with enhanced concentrations of heavy metals (arsenic, lead, copper, and chromium) appeared in rangeland sites, where land development and oil field activities were observed. The clay soil fraction emitted from dust storm sites was significantly associated with alkali earth metals (calcium, magnesium, and strontium) prone to traveling across the region in this fine particle fraction. Calcite, dolomite and gypsum were characteristic of dust storm sites in the Chihuahuan Desert, gypsum in the USA and the carbonates in the Mexican region of the Chihuahuan Desert. Southern High Plains region samples were dominated by quartz. Contoured mapping confirmed concentration affinities on the components mentioned above. Overall, this study shows an intricate linkage between the Southern High Plains and the Chihuahuan Desert regions as one regional-scale geoenvironmental system with combined effects on populations as a mineral aerosol source. These results can be used as a source apportionment tool to better understand and trace the environmental impacts of mineral dust storms locally, regionally, and continentally.
Environmental science|Environmental engineering|Geochemistry
Peinado, Porfirio, "Geochemical characterization of mineral dust sources in the Chihuahuan Desert and southern High Plains regions" (2013). ETD Collection for University of Texas, El Paso. AAI3565928.