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Composition, Alteration, And Texture Of Fault-Related Rocks From Safod Core And Surface Outcrop Analogs: Evidence For Deformation Processes And Fluid-Rock Interactions, Kelly Keighley Bradbury, Colter R. Davis, John W. Shervais, Susanne U. Janecke, James P. Evans
Composition, Alteration, And Texture Of Fault-Related Rocks From Safod Core And Surface Outcrop Analogs: Evidence For Deformation Processes And Fluid-Rock Interactions, Kelly Keighley Bradbury, Colter R. Davis, John W. Shervais, Susanne U. Janecke, James P. Evans
Geosciences Faculty Publications
We examine the fine-scale variations in mineralogical composition, geochemical alteration, and texture of the fault-related rocks from the Phase 3 whole-rock core sampled between 3,187.4 and 3,301.4 m measured depth within the San Andreas Fault Observatory at Depth (SAFOD) borehole near Parkfield, California. This work provides insight into the physical and chemical properties, structural architecture, and fluid-rock interactions associated with the actively deforming traces of the San Andreas Fault zone at depth. Exhumed outcrops within the SAF system comprised of serpentinite-bearing protolith are examined for comparison at San Simeon, Goat Rock State Park, and Nelson Creek, California. In the Phase …
Influences Of Lithology On Water Quality: A Study Of The Ngam And Mou Watersheds In West Cameroon (Central Africa), E. Kemayou Tchamako, Rv Tsinkou Fotsing, Jp Tchouankoue, Jr Ndam Ngoupayou, B Ngounou Ngatcha, Nancy W. Hinman
Influences Of Lithology On Water Quality: A Study Of The Ngam And Mou Watersheds In West Cameroon (Central Africa), E. Kemayou Tchamako, Rv Tsinkou Fotsing, Jp Tchouankoue, Jr Ndam Ngoupayou, B Ngounou Ngatcha, Nancy W. Hinman
Geosciences Faculty Publications
The Ngam and Mou Rivers belong to the river system of the central part of the Cameroon Volcanic Line. The Ngam River watershed comprises 51 Ma old basalts, while the Mou River watershed comprises younger, < 5 Ma pyroclastic basalts. The physico-chemical characteristics of water samples from both watersheds indicated pH between 4.2 and 8.2, and 4.2 to 7.5, and very low mineralization between 11 and 246 μS/cm and 45 to 165 μS/cm, respectively, for the Ngam River and the Mou River. Chemical data showed that waters from old, highly weathered plateau basalts (Ngam River watershed) were dominated by calcium and sodium (signatures of feldpars from syenites and orthogneisses), while waters in the Mou River watershed were dominated by magnesium (signature of olivines and pyroxenes from basalts). Mineralizations in the two watersheds are thus primarily controlled by lithology rather than anthropic activities. These results are promising for identifying potential potable water resources in these areas.
Water-Rock Interaction And Life, Nancy W. Hinman
Water-Rock Interaction And Life, Nancy W. Hinman
Geosciences Faculty Publications
Water-rock interactions play a critical role in the origin, existence, and prospects of life. Minerals are sources of energy and nutrients. Life uses aqueous chemical gradients to access and use minerals. Chemical disequilibrium, therefore, represents one type of biotic signature. Life also controls other types of disequilibrium, including isotopic disequilibrium and morphology. Water is a fundamental contributor to all of these biosignatures, acting as a medium for mass transfer and a reservoir for components. Distinguishing biosignatures from abiotic signatures challenges instrumental capabilities. Finally, the ubiquity and heterogenous distribution of life on Earth challenges the ability to interpret different types of …