『Abstract
Climate controls erosion and weathering on soil-mantled landscapes
through diverse processes that have remained difficult to disentangle
due to their complex interactions. We quantify denudation, soil
and saprolite weathering, and soil transport near the base and
crest of the western slope of the Sierra Nevada to examine how
large differences in climate affect these processes. Depth profiles
of fallout radionuclides and field observations show relative
differences in erosion and weathering processes at these two climatically
diverse sites, and our data suggest fundamentally different patterns
of soil production and transport mechanisms: biotically driven
soil transport at low elevation, and surface erosion driven by
overland flow at high elevation. Soil production rates from cosmogenic
10Be decrease from 31.3 to 13.6 m/Ma with increasing
soil depth at low elevation, but show uncertain depth dependence
at the high elevation site. Our data also show a positive correlation
between physical erosion and saprolite weathering at both sites.
Highly weathered saprolites are overlain by weakly weathered and
rapidly eroding soils, while chemically less depleted saprolites
are overlain by slowly eroding, more weathered soils. Our data
are among the first to quantify the critical role of saprolite
weathering in the evolution of actively eroding upland landscapes,
and our results provide quantitative constraints on how different
climates can shape hillslopes by driving processes of erosion
and weathering.』
Introduction
Study sites and approach
Patterns of erosion and chemical weathering
Sediment transport processes
Mechanistic controls on weathering and erosion
Conclusion
Acknowledgments
References cited