Calcium is a key element of the Earth system and closely coupled to carbon cycle. Weathering silicate releases Ca, which exported sequestered in oceans. However, pedogenic calcium carbonate constitutes second Ca-trapping pathway that has received less attention. Large accumulations nodules, associated with palaeo-Vertisols, are widespread North Cameroon, despite carbonate-free watershed. A prev...

The geochemical characteristics of a near shore inland aquifer system have been investigated in the Coastal Aquifer Test Field (CAT-Field) between Bremerhaven and Cuxhaven in the Northern Part of Germany which is described by Kessels et al.(this issue). Groundwater and sediment samples from the aquifer were taken at different locations on the flank of a glacial channel at depths between 5 and 1...

Microbial community structures in deep-sea hydrothermal vents fields are constrained by available energy yields provided by inorganic redox reactions, which are in turn controlled by chemical composition of hydrothermal fluids. In the past two decades, geochemical and microbiological studies have been conducted in deep-sea hydrothermal vents at three geographically different areas of the Southe...

We have constructed a conceptual model of biogeochemical cycles and metabolic and microbial community shifts within a hot spring ecosystem via coordinated analysis of the "Bison Pool" (BP) Environmental Genome and a complementary contextual geochemical dataset of ~75 geochemical parameters. 2,321 16S rRNA clones and 470 megabases of environmental sequence data were produced from biofilms at fiv...

A detailed geochemical study and a sequence stratigraphic interpretation have been conducted on a sedimentary sequence of the Upper Cretaceous La Luna Formation, in a section outcropping in the eastern ̄ank of the Middle Magdalena Basin (MMB), Colombia. The goals were to evaluate geochemical variability related to lithofacies and organic facies changes, characterize depositional environment and...

Soils are an important site of carbon storage1. Climate is generally regarded as one of the primary controls over soil organic carbon1,2, but there is still uncertainty about the direction and magnitude of carbon responses to climate change. Here we show that geochemistry, too, is an important controlling factor for soil carbon storage.Wemeasured a range of soil and climate variables at 24 site...

A two-dimensional model for virus transport in physically and geochemically heterogeneous subsurface porous media is presented. The model involves solution of the advection-dispersion equation, which additionally considers virus inactivation in the solution, as well as virus removal at the solid matrix surface due to attachment (deposition), release, and inactivation. Two surface inactivation m...

[1] We integrate groundwater geochemistry, mineralogy, and numerical modeling techniques to study the reactive transport of heavy metals and isotopes in the Eutaw coastal plain aquifer, Alabama. Geochemical data show that the elevated concentrations of Fe, Mn, and Sr can be correlated with high pH and alkalinity. These geochemical correlations suggest that that elevated metal concentrations may...

Predicting and controlling the concentrations of redox-sensitive elements are primary concerns for environmental remediation of contaminated sites. These predictions are complicated by dynamic flow processes as hydrologic variability is a governing control on conservative and reactive chemical concentrations. Subsurface heterogeneity in the form of layers and lenses further complicates the flow...