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...

The southwestern tropical Pacific, part of a major pathway for waters feeding the Equatorial Undercurrent, is a region of important geochemical enrichment through land-ocean boundary exchange. Here we develop an original method based on the coupling between dynamical modeling and geochemical tracer data to identify regions of enrichment along the water pathways from the subtropics to the equato...

Within reactive geochemical transport, several conceptual models exist for simulating sorption processes in the subsurface. Historically, the KD approach has been the method of choice due to ease of implementation within a reactive transport model and straightforward comparison with experimental data. However, for modeling complex sorption phenomenon (e.g. sorption of radionuclides onto mineral...

Abstract An approach, combining several geochemical methods, was used to determine the groundwater properties and components of a hypogene karst system, where sampling is restricted only spring sites, with limited number available locations. Radiogenic isotopes ( 3 H, 14 C) were constrain mean residence time separate different components. Noble gases, stable water (δ 18 O, δ 2 H), dissolved ino...

The geochemical history of an upper deltaic plain pending tidal wetland restoration was reconstructed to assess remobilization of redox-sensitive constituents in sediment, identify depositional processes promoting geochemical retention, and determine the extent of contamination with Hg, As, Pb, Cu, and Zn. Three 12-14-m sediment cores were analyzed for bulk sediment geochemistry using ICP-AES. ...

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...

A variety of regional geoscience datasets from Nova Scotia have been co-registered and analyzed using a geographic information system (GIS). The datasets include bedrock and surficial geological maps, airborne geophysical survey data, geochemistry of lake-sediment samples, and mineral occurrence data. A number of line features, including structural lineaments, fold axes and formation contacts, ...

This report presents some strategies to predict metal mobility at mining sites. These strategies are based on chemical, physical, and geochemical information about metals and their interactions with the environment. An overview of conceptual models, metal sources, and relative mobility of metals under different geochemical conditions is presented, followed by a discussion of some important phys...

Regional geochemical survey (RGS) results for the lskut River (1048). Telegraph Creek (104G) and Tulsequah (104K) areas were released in July 1988. The release consists of chemical and physical data for sediment and water samples collected from more than 2700 streams over an area of 35 000 square kilometres underlain by 50 different rock units. For each sample over 40 variables were recorded in...