1000 resultados para 76-534A
Resumo:
Fil: Dip, Nicolás. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.
Resumo:
Fil: Dip, Nicolás. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.
Resumo:
Four dominant depositions of carbonaceous claystones are recognized to have occurred during the early Aptian to middle Albian at Site 534. There are correlations of stable isotope ratios with organic carbon content and of clay content with clay mineralogy of the samples. Almost all organic carbon in these sequences has very negative terrestrial isotope ratios, and the clay of that age indicates predominance of aluminous montmorillonite, which is thought to be of terrigenous origin. It is suggested that development of coastal vegetation belts and deltaic outbuilding with consequent outpouring of land-plant detritus and terrigenous elastics into the deep basins probably led to formation of the "black shale" facies.