An understanding of rates and mechanisms of incision and knickpoint retreat in bedrock rivers is fundamental to perceptions of landscape response to external drivers, yet only sparse field data are available. Here we present eye witness accounts and quantitative surveys of rapid, amphitheatre-headed gorge formation in unweathered granite from the overtopping of a rock-cut dam spillway by small-...

A global compilation of erosion rates and modeled dust fluxes shows that dust inputs can be a large fraction of total soil inputs, particularly when erosion is slow and soil residence time is therefore long. These observations suggest that dust-derived nutrients can be vital to montane ecosystems, even when nutrient supply from bedrock is substantial. We tested this hypothesis using neodymium i...

Abstract Dual medium geometric model is widely used in soil and rock mass environment, which can only reflect the material exchange between cracks matrix. The dual ignores hydraulic relationship pores cracks. paper develops a new method to construct three-dimensional geometry model. This completely written by Matlab scripting language, describe real spatial distribution state of fracture bedroc...

Base metal smelting activities can produce acidic rain that promotes vegetation loss and the development of black coatings on bedrock. Such coatings can form over large areas and are among the most prominent long-term vestiges of past smelting activities. In this study, multispectral images derived from Hyperion reflectance data were evaluated with regard to their utility in the discrimination ...

Stochastic groundwater models enable the characterization of geological uncertainty. Often the major source of uncertainty is not related to aquifer heterogeneity, but to the general shape of the aquifer. This is especially the case in paleovalley-type alluvial aquifers where the bedrock surface limits the extent of easily extractable groundwater. Determining the shape of a bedrock surface is n...

Biotite is a common constituent of silicate bedrock. Its weathering releases plant nutrients and consumes atmospheric CO2. Because of its stoichiometric relationship with its transformational weathering product and sensitivity to botanical activity, calculating biotite weathering rates using watershed mass-balance methods has proven challenging. At Coweeta Hydrologic Laboratory the coupling of ...

The transition from 41to 100-kyr glacial cycles and concomitant increase in global ice volume ~1 Ma remain an enigmatic feature of late Cenozoic climate. Here, we examine the petrology, mineralogy, and geochemistry of the silicate fraction of tills spanning the past 2 Ma from the north-central United States to evaluate the hypothesis that this so-called middle Pleistocene transition (MPT) occur...