Kreyenhagen shale

The primary source of the selenium is believed to have been pyrite in shales, particularly the Upper Cretaceous-Paleocene Moreno Shale and the Eocene-Oligocene Kreyenhagen Shale. Concentrations of selenium in these formations range up to 45 mg kg median concentrations being 6.5 mg kg and 8.7 mg kg respectively (Presser, 1994). The concentration of selenium in the surface sediments (0-0.3 m depth) of the old playas is in the range l-20mgkg reflecting the historical accumulation of selenium from the selenium-rich drain water. Deeper sediments... 

At North Coles Levee, carbon isotope values fluctuate between zero and -12%o in cements estimated to have formed at intermediate burial depths between 4 and 5 Ma (Wood Boles, 1991). These fluctuations are interpreted as being the result of pulses of fluid from deep basin levels mixing with local fluids (Wood Boles, 1991). Burial history reconstruction for the basin indicates that shale source rocks, such as the Eocene Kreyenhagen, would have been at an appropriate depth to be a CO2 source (Fig. 3). 

Fig. 5. Weight percent of original organic matter converted to aqueous C2-C5 mono-carboxylic acids after hydrous pyrolysis of aliquots of Kreyenhagen, Monterey, and Phosphoria Retort shales isothermally heated at temperatures from 240 to 365 for 72-h durations. Experiments were conducted in carburized stainless steel-316 reactors in the authors laboratory...

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