Holocene colluvial and alluvial stratigraphy and a radiocarbon chronology are presented for the valley of the lower three kilometers of Raven Fork, a mountain stream draining 194 km2 of high relief (1.3 km) terrain of the Southern Blue Ridge Mountains in western North Carolina, USA, which is in a region that lacks good chronological data. Lower hillslopes, alluvial/ colluvial fans, alluvial bot...

Using data from a water-balance instrument cluster with spatially distributed sensors we determined the magnitude and within-catchment variability of components of the catchmentscale water balance, focusing on the relationship of seasonal evapotranspiration to changes in snowpack and soil moisture storage. Co-located, continuous snow depth and soil moisture measurements were deployed in a rain–...

Continental weathering is a fundamental process in releasing magnesium (Mg) from crystalline rocks to the hydrosphere and biosphere. Mg isotopes can be substantially mobilized, re-distributed, fractionated during weathering, therefore used as powerful tool trace biogeochemical cycle of Mg. Causes significant isotopic fractionation behaviors silicate are still not well understood, hindering furt...

Soil vapor extraction (SVE) systems are intended to cause substantial volumes of air to flow through the subsurface with the purpose of removing volatile contaminants. The effectiveness of SVE can be influenced by any effect that changes the specific gas capacity (discharge as a function of vacuum) of a well. Skins of low permeability material enveloping a well bore are widely recognized to aff...

-The proposed method is a modification of one by Alexiades and Jackson (1965). Calcium exchange capacity (CaEC) and potassium exchange capacity (KEC) are determined, after removal of organic matter and free iron oxides, by saturating the exchange complex with centrifuge washings of pH 7 acetate solutions of Ca or K, respectively. Excess salt in solutions remaining in contact with the soil after...

Abstract The Santa Fé Ni-Co deposit is a major undeveloped lateritic located in the Goiás State of Central Brazil. comprises two properties that together have indicated resources 35.7 million tonnes (Mt), grading 1.14% Ni and 0.083% Co, inferred 104.3 Mt at 1.03% 0.054% Co. laterite was derived from Late Cretaceous alkaline ultramafic lithologies experienced an initial silicification Eocene to ...

Silicon (Si) is an important nutrient for many plant and algae species, the ultimate source of Si silicate mineral weathering reactions. These topics have inspired application isotope geochemistry to quantifying cycling in Critical Zone, though interpretations are often equivocal. Because germanium (Ge) similar that Si, Ge/Si ratio considered a tracer provides additional constraints on cycling....

The semi-arid sagebrush steppe in the western United States faces pressures from agriculture industry, recreation use, invasive grasses, and a changing climate. A key to facilitating healthy management of this ecosystem is understanding distribution behavior soil moisture vadose zone both natural agricultural settings. Within unsaturated environments, spatially temporally heterogeneous, changes...

Passive margin escarpments are extensively studied around the world, and understanding their evolution continues to present one of the more compelling interdisciplinary challenges tackled by earth scientists today. Escarpments reflect the morphotectonic development of passive margins and can separate regions with different climatic histories, but the inferred rapid rates of escarpment retreat h...

Estimation of the temperature dependence of natural feldspar weathering in two catchments at different elevations yields an apparent Arrhenius activation energy of 18.4 kcal/mol (77.0 kj/mol), much higher than most laboratory values. This finding supports recent suggestions that hydrolytic weathering of silicate minerals may consume carbonic acid and thereby remove atmospheric carbon dioxide mo...