[1] Successful geologic sequestration of carbon in deep saline aquifers requires accurate predictive models of rock-brine-CO2 interaction. Often overlooked in siliciclastichosted saline reservoirs is the carbonate buffering of the groundwater. Carbonate minerals are ubiquitous, even in siliciclastic host rocks, resulting in some carbonate buffering. Geochemical modeling of rock-brine-CO2 system...

Studies of dunefields in central and western North America show that mineralogical maturity can provide new insights into the origin and evolution of aeolian sand bodies. Many of the world’s great sand seas in Africa, Asia and Australia are quartzdominated and thus can be considered to be mineralogically mature. The Algodones (California) and Parker (Arizona) dunes in the southwestern United St...

Climate is an important environmental parameter of the early Earth, likely to have affected the origin and evolution of life, the composition and mineralogy of sedimentary rocks, and stable isotope ratios in sedimentary minerals. There is little observational evidence constraining Precambrian climates. Most of our knowledge is at present theoretical. Factors that must have affected the clima...

New occurrences of xenolithic alkaline rocks from three East African volcanoes are described. Micro-ijolites and alkali pyroxenites occur in the carbonate-rich tufts and lavas of Mount Elgon; kaersutite-rich pyroxenites and a suite of fenitized basement rocks in the caldera flows of Mount Meru, and apparently unique melanocratic hortonolite nepheline syenites in the central foyaite plug of Moun...

Two-dimensional (2D) NMR techniques have been proposed as efficient methods to infer a variety of petrophysical parameters, including mixed fluid saturation, in-situ oil viscosity, wettability, and pore structure. However, no study has been presented to quantify the petrophysical limitations of such methods. We address this problem by introducing a pore-scale framework to accurately simulate su...

Rupture fronts can cause fault displacement, reaching speeds up to several ms(-1) within a few milliseconds, at any distance away from the earthquake nucleation area. In the case of silicate-bearing rocks the abrupt slip acceleration results in melting at asperity contacts causing a large reduction in fault frictional strength (i.e., flash weakening). Flash weakening is also observed in experim...

Cave collapses emerge during the process of oil reservoir development, seriously affecting oil production. To reveal the collapse and failure mechanism of the carbonate cavern with a buried depth of 5600 m in Tahe Oil Field, using a self-developed ultra-high pressure model test system with the intelligent numerical control function, the model simulation material of carbonate rocks developed to ...

[1] Galileo spacecraft data obtained from Jupiter’s ice-covered satellite Europa suggest the existence of a subsurface water ocean. The formation of this ocean is a direct consequence of early igneous and hydrothermal processes that may have facilitated oxidation through H2 and CH4 escape. These processes could have led to a moderately alkaline sulfate-carbonate ocean and a moderately oxidized ...

The study of the O and C isotope composition calcite from nepheline syenites, ijolites carbonatites Chik intrusion intrusions Erzin–Tarbagatay group Sangilen (Eastern Siberia, Russia) showed derivation alkaline melts enriched with a carbonate component host marbleized sedimentary rocks. calculations that about 40% initial mass carbonates involved in interaction silicate have remained after deca...

The purpose of this study was to elucidate the processes controlling the distribution and behavior of the longerlived Ra isotopes in continuous Paleozoic carbonate aquifers of parts of Missouri, Kansas, and Oklahoma. Activities of (Ra) and (Ra) were analyzed in fresh and saline ground waters, brines, and rocks. The ̄uids have a wide salinity range (200±250,000 mg lÿ1 total dissolved solids). Th...