Publication date: 15 March 2018
Source:Geoderma, Volume 314
Author(s): Rebecca A. Lybrand, Craig Rasmussen
Mineral weathering transforms rock into soils that supply nutrients to ecosystems, store terrestrial carbon, and provide habitat for organisms. As a result, the mineralogy and geochemistry of soils from contrasting environments are well-studied. The primary objective of this research was to examine how climate, topography, and dust interactively control the mineral and geochemical composition of granitic soils that span an environmental gradient in southern Arizona. Two field sites were selected within the Catalina Critical Zone Observatory that exhibit significant range in precipitation (25 to 85catena end member pairs were selected to represent variation in local topography which included divergent, water-shedding summits and convergent, water-gathering footslopes. Soils and parent rock were studied using x-ray diffraction and x-ray fluorescence. Dust samples were collected from ridgetop dust traps at the desert scrub site and examined using x-ray fluorescence. The desert scrub soils showed enrichment in biotite, total feldspar, and Fe
Source:Geoderma, Volume 314
Author(s): Rebecca A. Lybrand, Craig Rasmussen