The Rb/Sr ratios of lake sediments have been suggested as indicators of weathering intensity by increasing work. However, the geochemistry of Rb/Sr ratios of lake sediments is variable between different lakes. In this study, we investigated the spatial and temporal patterns of Rb/Sr ratios, as well as those of other major elements in surface sediments of Lake Qinghai. We find that the spatial p...

White women experience their lowest rate of low birth weight (LBW) in their late 20s; the nadir LBW for AfricanAmerican women is under 20 years with rates rising monotonically thereafter, hypothesized as due to ‘‘weathering’’ or deteriorating health with cumulative disadvantage. Current residential environment affects birth outcomes for all women, but little is known about the impact of early l...

Title of Document: TRACING CONTINENTALWEATHERING USING LITHIUM AND MAGNESIUM ISOTOPES: INSIGHTS FROM THE CHEMICAL WEATHERING OF COLUMBIA RIVER BASALTS AND MASS BALANCE MODELING Xiao-Ming Liu, Ph.D., 2013 Directed By: Professors Roberta L. Rudnick & William F. McDonough, Department of Geology Chemical weathering is an important mechanism that changes the mass and composition of the continental c...

Tectonic uplift is one of the key factors controlling the supply of material to weathering environments. At present however, there is debate about whether tectonics or climate plays a larger role in controlling chemical weathering rates on a global scale over geologic time. We measured riverine weathering fluxes from twelve catchments along the Skykomish River in the Washington Cascades, where ...

Landscapes evolve in response to external forces, such as tectonics and climate, that influence surface processes of erosion and weathering. Internal feedbacks between erosion and weathering also play an integral role in regulating the landscapes response. Our understanding of these internal and external feedbacks is limited to a handful of field-based studies, only a few of which have explicit...

Weathering of silicate minerals impacts many geological and ecological processes. For example, the weathering of basalt contributes significantly to consumption of atmospheric carbon dioxide (CO2) and must be included in global calculations of such consumption over geological timeframes. Here we compare weathering advance rates for basalt (wD β ), where D and β indicate the scale at which the r...

Connections between glaciation, chemical weathering, and the global carbon cycle could steer the evolution of global climate over geologic time, but even the directionality of feedbacks in this system remain to be resolved. Here, we assemble a compilation of hydrochemical data from glacierized catchments, use this data to evaluate the dominant chemical reactions associated with glacial weatheri...

The relationships among climate, physical erosion, and chemical weathering have remained uncertain, because long-term chemical weathering rates have been difficult to measure. Here we show that long-term chemical weathering rates can be measured by combining physical erosion rates, inferred from cosmogenic nuclides, with dissolution losses, inferred from the rock-to-soil enrichment of insoluble...