Separation of geochemical anomalies from background has always been a major concern of exploration geochemistry. The search for methods that can make this analysis quantitative and objective aims not only at the reduction of subjectiveness but also at providing an automatic routine in exploration, assisting the interpretation and production of geochemical maps. This report discusses two methodo...

Reactive transport modelling of dissolved CO 2 in porous media iii Dedicated to my parents (late) and eldest sister. iv Reactive transport modelling of dissolved CO 2 in porous media v ABSTRACT The geological sequestration of carbon dioxide (CO 2) is seen as one of the options of mitigating the imbalance of greenhouse gas emissions and to avoid global warming. However, leakage of CO 2 from the ...

In an attempt to quantify the extent of geochemical heterogeneity within a restricted and well dated portion of the upper mantle, 27 chromite separates from the 90 My old chromite deposits in the Mayarı́–Baracoa ophiolite belt in eastern Cuba have been investigated for platinum group element (PGE) concentrations and Re–Os isotopic systematics. The samples are characterized by systematically subc...

Historical sediment nutrient concentrations and heavy-metal distributions were studied in fi ve embayments in the Gulf of Finland and an adjacent lake. Th e main objective of the study was to examine the response of these water bodies to temporal changes in human activities. Sediment cores were collected from the sites and dated using 210Pb and 137Cs. Th e cores were analyzed for total carbon (...

Large Igneous Provinces (LIPs) are unusual volcanic events in which massive amounts of melt (∼106 km3) erupt relatively short time periods (<106 years). Most LIP magmas have undergone extensive fractional crystallization and crustal contamination, but the magmatic plumbing systems processes triggering eruptions poorly understood. We present new major trace element radiogenic isotope data for 43...

Authigenic carbonate was recently invoked as a third major global carbon sink in addition to primary marine carbonate and organic carbon. Distinguishing the two carbonate sinks is fundamental to our understanding of Earth's carbon cycle and its role in regulating the evolution of atmospheric oxygen. Here, using microscale geochemical measurements of carbonates in Early Triassic strata, we show ...

A chemical kinetics algorithm is presented for geochemical applications. The algorithm is capable of handling both equilibriumand kinetically-controlled reactions in multiphase systems. The ordinary differential equations (ODEs) are solved using an implicit multistep backward differentiation formula (BDF) algorithm to ensure efficiency and stability when integrating stiff ODEs. An adaptive cont...

A synthetic Topopah Spring Tuff water representative of one type of pore water at Yucca Mountain, NV was evaporated at 95 °C in a series of experiments to determine the geochemical controls for brines that may form on, and possibly impact upon the long-term integrity of waste containers and drip shields at the designated high-level, nuclear-waste repository. Solution chemistry, condensed vapor ...

Reactive fluid flow and geochemical transport in unsaturated fractured rocks have received increasing attention for studies of contaminant transport, groundwater quality, waste disposal, acid mine drainage remediation, mineral deposits, sedimentary diagenesis, and fluid-rock interactions in hydrothermal systems. This paper presents methods for modeling geochemical systems that emphasize: (1) in...