[1] We evaluate the accuracy of 1 m, LiDAR-derived DEMs of an exposed bedrock channel, and use these highresolution terrain models to calculate erosional fluxes between four levels of strath terraces dated previously with Be. Recent investigations into the timing, rates, and processes by which rivers incise their bedrock channels have greatly enhanced our understanding of landscape evolution. H...

A quartz-pyroxene rock interpreted as a banded iron formation (BIF) from the island of Akilia, southwest Greenland, contains (13)C-depleted graphite that has been claimed as evidence for the oldest (>3850 million years ago) life on Earth. Field relationships on Akilia document multiple intense deformation events that have resulted in parallel transposition of Early Archean rocks and significant...

A 20-m-wide trench was excavated to bedrock on a hillslope at the Panola Mountain Research Watershed in the Piedmont region of Georgia to determine the effect of upslope drainage area from the soil and bedrock surfaces on the geochemical evolution of base cation concentrations in subsurface flow. Samples were collected from ten 2-m sections and five natural soil pipes during three winter rainst...

[1] Recent theoretical models suggest that topographic characteristics of bedrock channels are products of interactions among tectonics, substrate resistance, and the climatically modulated erosive ability of the river. The degree to which these factors influence the form of channel profiles is poorly quantified at present. Here we investigate bedrock channels developed across the southern flan...

Population statistics for As concentrations in rocks, sediments and ground water differ by geology and land use features in the New England region, USA. Significant sources of As in the surficial environment include both natural weathering of rocks and anthropogenic sources such as arsenical pesticides that were commonly applied to apple, blueberry and potato crops during the first half of the ...

Introduction: The Mars Global Surveyor Thermal Emission Spectrometer (TES) has a spatial resolution of ~ 3 x 6 km/pixel, with 143 spectral bands between 50-6 µm (~200-1600 cm-1). Previous compositional studies using TES data have been conducted at the multi-pixel (tens to thousands) level [1-6]. At these spatial scales (>30 km), outcrops of bedrock cannot be resolved, therefore surface composit...

[1] Numerical models of bedrock valley development generally do not include weathering explicitly. Nevertheless, weathering is an essential process that acts in concert with the transport of loose debris by seepage and runoff to form many bedrock valleys. Here we propose a numerical model for bedrock valley development that explicitly distinguishes weathering and the transport of loose debris a...

Ultramafic-mafic rocks from Makrirrakhi, Central Greece exhibit features of an original ophiolite sequence which contains depleted mantle material, ultramafic containing partial melt textures and possibly the marie "pluton" which resulted from the coalescing of these partial melt segregations. Considerable mineralogical variation exists: unzoned olivine crystals range in composition from FoTs_s...