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Linking Lithology And Land Use To Sources Of Dissolved And Particulate Organic Matter In Headwaters Of A Temperate, Passive-Margin River System, Steven T. Petsch, B. E. Longwortha, P. A. Raymond, J. E. Bauerc
Linking Lithology And Land Use To Sources Of Dissolved And Particulate Organic Matter In Headwaters Of A Temperate, Passive-Margin River System, Steven T. Petsch, B. E. Longwortha, P. A. Raymond, J. E. Bauerc
Steven T. Petsch
A number of rivers have been found to transport highly aged organic matter [OM]; however, the sources of this aged material remain a matter of debate. One potential source may be erosion and weathering of headwater lithologies rich in ancient sedimentary OM. In this study, waters, suspended particulates, streambed sediments, rocks and soils from fourteen small headwater watersheds of a mid-size, temperate, passive margin river were sampled and characterized by Δ14C, δ13C, and POC/TPN ratios to identify sources of particulate and dissolved OM delivered to the river mainstem. These headwater sites encompass a range in lithology (OM-rich shales, OM-lean carbonate/mudstone …
Salinity Constraints On Subsurface Archaeal Diversity And Methanogenesis In Sedimentary Rock Rich In Organic Matter, Steven T. Petsch, P. Waldron, A. M. Martini, K. Nüsslein
Salinity Constraints On Subsurface Archaeal Diversity And Methanogenesis In Sedimentary Rock Rich In Organic Matter, Steven T. Petsch, P. Waldron, A. M. Martini, K. Nüsslein
Steven T. Petsch
The diversity of microorganisms active within sedimentary rocks provides important controls on the geochemistry of many subsurface environments. In particular, biodegradation of organic matter in sedimentary rocks contributes to the biogeochemical cycling of carbon and other elements and strongly impacts the recovery and quality of fossil fuel resources. In this study, archaeal diversity was investigated along a salinity gradient spanning 8 to 3,490 mM Cl− in a subsurface shale rich in CH4 derived from biodegradation of sedimentary hydrocarbons. Shale pore waters collected from wells in the main CH4-producing zone lacked electron acceptors such as O2, NO3−, Fe3+, or SO42−. Acetate …