Clay Mineralogy, Spore Coloration and Diagenesis in Middle Miocene Sediments of the Niger Delta
Francisca E. Oboh, 1992. "Clay Mineralogy, Spore Coloration and Diagenesis in Middle Miocene Sediments of the Niger Delta", Origin, Diagenesis, and Petrophysics of Clay Minerals in Sandstones, David W. Houseknecht, Edward D. Pittman
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The clay-mineral assemblage of Middle Miocene sediments from the E2.0 Reservoir (3,590–3,655 m) in the Kolo Creek field is correlated with the color of palynomorphs in order to understand the level of diagenesis experienced by the sediments. The clay minerals in the mudstones are predominantly detrital kaolinite with significant amounts of illite/smectite, whereas in the sandstones, clays occur in minor amounts as mainly authigenic kaolinite. Quantitative measurements of the color of palynomorphs show that the sediments are immature to marginally mature and this level of maturity can be related to early diagenetic conditions before the emplacement of oil in the reservoir. A plot of palynomorph carbonization (luminance) versus percent illite in illite/smectite shows a fairly good correlation (statistically significant at a 95% level of confidence) between the two diagenetic parameters. The low level of maturity is not obvious from Kubler's illite crystallinity index for the mudrocks, which show a considerable variation over a short depth range.
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Origin, Diagenesis, and Petrophysics of Clay Minerals in Sandstone–This volume grew out of a symposium held at the 27th Annual Meeting of the Clay Minerals Society in Columbia, Missouri on October, 1990. The symposium was designed to present a current synthesis of research devoted to the origin, diagenesis and petrophysics of clay minerals in sandstones. International authors demonstrate a multidisciplinary approach to interpreting the origin and diagenesis of clay minerals in sandstones and to evaluating their influence on reservoir quality. This volume bridges a gap between petrographic and geochemical researchers and reservoir geologists and engineers.