We used cosmogenic nuclide and geochemical mass balance methods to measure long-term rates of chemical weathering and total denudation in granitic landscapes in diverse climatic regimes. Our 42 study sites encompass widely varying climatic and erosional regimes, with mean annual temperatures ranging from 2 to 25 jC, average precipitation ranging from 22 to 420 cm year , and denudation rates ran...

It has been hypothesized that predecessors of today's bryophytes significantly increased global chemical weathering in the Late Ordovician, thus reducing atmospheric CO2 concentration and contributing to climate cooling and an interval of glaciations. Studies that try to quantify the enhancement of weathering by non-vascular vegetation, however, are usually limited to small areas and low number...

Much of the literature that analyzes the effect of various factors on basaltic weathering rates does not assess the synergistic effects of several factors at once. Those studies that do address such synergies generally report their results in formats that are difficult to integrate into geographic analysis. The research outlined in this paper employs multivariate statistics to assess the effect...

The severity of oil spills depends on the quantity material released and its physical chemical properties. total amount petroleum spilled during Deepwater Horizon incident relative fractions compound classes Macondo were obtained by measurements, observations, model calculations, with a significant uncertainty. Because is an extremely complex mixture many thousands or more gaseous, liquid, soli...

The effects of mineralogy and geological setting on trace metal concentration and distribution within six weathered profiles developed sandstone and mudstone was assessed. Primary minerals occurring in the weathered profiles are quartz, plagioclase, and K-feldspar. Kaolinite is the most dominant secondary mineral followed by mixed layers of smectite-illite, illite, hematite, siderite, and occas...

[1] We developed a process-oriented hillslope soil mass balance model that integrates chemical and physical processes within hillslope soils. The model explicitly factors that soil chemical weathering at any hillslope position is related to the flux of soil eroded from upslope as well as soil production from underlying bedrock. The model was merged with measurements of soil elemental chemistry ...

In unglaciated terrain, the imprint of past glacial periods is difficult to discern. The topographic signature periglacial processes, such as solifluction lobes, may be erased or hidden by time and vegetation, thus their import diminished. Belowground, weathering, particularly frost cracking, have imparted a profound influence on weathering erosion rates during climate regimes. By combining mec...

Evaluating conflicting theories about the influence of mountains on carbon dioxide cycling and climate requires understanding weathering fluxes from tectonically uplifting landscapes. The lack of soil production and weathering rate measurements in Earth's most rapidly uplifting mountains has made it difficult to determine whether weathering rates increase or decline in response to rapid erosion...