The Role of Mixing and Migration of Basinal Waters in Carbonate Mineral Mass Transport
Published:January 01, 1997
John W. Morse, Jeffrey S. Hanor, Shiliang He, 1997. "The Role of Mixing and Migration of Basinal Waters in Carbonate Mineral Mass Transport", Basin-Wide Diagenetic Patterns: Integrated Petrologic, Geochemical, and Hydrologic Considerations, Isabel P. Montanez, Jay M. Gregg, Kevin L. Shelton
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Most sedimentary basins contain close to 20% by volume pore water; much of which is of high ionic strength and is classified as brine. Although considerable variation occurs in the composition of basinal waters, some correlation exists between major ion concentrations and total dissolved solids. It is consequently possible to construct geochemical models for basinal waters that have general utility for investigating a variety of subsurface processes.
In this paper, we examine the potential role of brine composition and movement on carbonate mineral mass transport in sedimentary basins up to pressure and temperature conditions of 300 bars and 100°C. Primary emphasis is placed on the impact of vertical and lateral migration of brines and the dispersive mixing of brines with waters containing widely varying concentrations of total dissolved solids. Model results indicate that mixing of subsurface waters may produce fluids which are highly supersaturated and at times slightly undersaturated with respect to calcite. This process may represent a major mechanism for production and destruction of carbonate cements in sediments. It may also offer an explanation as to how basinal scale mass transfer of carbonates can occur in waters that are close to equilibrium with respect to major sedimentary carbonate minerals.
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Basin-Wide Diagenetic Patterns: Integrated Petrologic, Geochemical, and Hydrologic Considerations
This volume contains papers, many of which were presented at the SEPM Research Conference entitled Basin-Wide Diagenetic Patterns: Integrated Petrologic, Geochemical, and Hydrologic Considerations which was convened May 21 to 25, 1994 at Lake Ozark, Missouri, U.S.A. Some of the issues addressed at this conference and in this volume include: factors governing the temporal evolution of hydrodynamic systems, the origin and evolution, and spatial distribution of paleoflow conduits and their diagenetic products in sedimentary basins, the nature of subsurface fluid-rock interactions, temporal and spatial distribution of the geochemistry of basinal fluids, and factors controlling heat flow in sedimentary basins.