Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition. The absence of predicted geochemical variations indicate...

[1] The Earth’s surface is shaped by the interaction of tectonics, water, sediment, solutes, and biota over a wide range of spatial and temporal scales and across diverse environments. Development of a predictive science of Earth surface dynamics integrates many disciplines and approaches, including hydrology, geomorphology, ocean and atmospheric science, sedimentary and structural geology, geo...

IN CHROMITE VERSUS SEDIMENTARY PGE SIGNATURES B. Schmitz , P. R. Heck, C. Alwmark, N. T. Kita, B. Peucker-Ehrenbrink, T. Ushikubo, and J. W. Valley, Department of Geology, Sölvegatan 12, Lund University, SE-22362 Lund, Sweden, [email protected], Department of Geology and Geophysics, University of Wisconsin, 1215 W. Dayton St., Madison, WI 53706, USA, Department of Marine Chemistry and G...

We examined the use of dC, TOC and C/N geochemistry of sedimentary organic matter to reconstruct former sea levels and paleoenvironments in the absence of suitable microfossil data. The modern distribution of dC, TOC and C/N of 33 vegetation and 74 surface sediment samples collected from four coastal wetlands in the Thames Estuary and Norfolk, UK are described. The dC, TOC and C/N geochemistry ...

miocene silisiclastic sediments in binalood zone consist of three lithofacies group including gravelly (gmm, gcm, gci, gh, gt, gp), sandy (st, sm, sh, sp, ss, sl) and muddy (fm, fl). gravelly lithofacies are generally massive and mainly consist of volcanic and sedimentary lithic in different size. sandy lithofacies are composed of litharenite and feldespathic volcanicarenite and rock fragments ...

New mapping, geochronology, and geochemistry of the supracrustal enclave and associated orthogneisses at Akilia, West Greenland, support a >3825 6 Ma age for the sequence and a chemical sedimentary origin for the controversial Fe-rich quartz-pyroxene gneisses. Lithologies of the enclave comprise laterally continuous, mappable units of mafic amphibolite, ultramafic rocks, and two Fe-rich quartzp...

A novel hydrodynamic-driven stability analysis is presented for surface patterns on speleothems, i.e., secondary sedimentary cave deposits, by coupling fluid dynamics to the geochemistry of calcite precipitation or dissolution. Falling film theory provides the solution for the flow-field and depth perturbations, the latter being crucial to triggering patterns known as crenulations. In a wide ra...

The geochemistry of river sediments is routinely used to obtain information about geologic and environmental processes occurring upstream. For example, downstream samples are constrain chemical weathering physical erosion rates upstream, as well the locations mineral deposits or contaminant sources. Previous work has shown that, by assuming conservative mixing, can be reliably predicted given a...