(Table T1) Fluid inclusions in siltstone and sandstone grains from ODP Hole 210-1276A

Twenty samples of siltstones and sandstones were taken from Ocean Drilling Program Site 1276 during Leg 210 for fluid inclusion studies. With the exception of one sample of vein calcite, all inclusions were in quartz grains. The results of fluid-inclusion petrology and microthermometry indicate the presence of three fluid inclusion types (Types 1, 2, and 3). Type 1 fluid inclusions are two-phase (liquid + vapor) aqueous inclusions, and Type 2 inclusions are monophase fluid inclusions (liquid or vapor). These are common in all samples and are formed either as primary isolated inclusions or as secondary inclusions as trails along annealed fractures in the grain. Type 3 fluid inclusions are three-phase (liquid + vapor + solid) inclusions. Type 3 inclusions are rare and are observed as isolated inclusions or in a cluster with other types (i.e., Types 1 and 2). The predominant population throughout the different units sampled is two-phase (liquid + vapor) aqueous fluid inclusions (i.e., Type 1). The temperature of homogenization (TH) bivariate plots for Type 1 inclusions shows dominance throughout the hole of low- to medium-salinity fluids with minimum trapping temperatures between 150° and 400°C.

Lithology, stratigraphy, organic carbon content, extract and liquid chromatography yields, and Rock-Eval pyrolysis at DSDP Holes 75-530A and 75-532

Seventeen sediment samples of Albian-Cenomanian to early Pliocene age from DSDP Hole 530A in the Angola Basin and six sediment samples of early Pliocene to late Pleistocene age from the Walvis Ridge were investigated by organic geochemical methods, including organic carbon determination, Rock-Eval pyrolysis, gas chromatography and combined gas chromatography/mass spectrometry of extractable hydrocarbons, and kerogen microscopy. The organic matter in all samples is strongly influenced by a terrigenous component from the nearby continent. The amount of marine organic matter present usually increases with the total organic carbon content, which reaches an extreme value of more than 10% in a Cenomanian black shale from Hole 530A. At Site 530 the extent of preservation of organic matter in the deep sea sediments is related to mass transport down the continental slope, whereas the high organic carbon contents in the sediments from Site 532 reflect both high bioproductivity in the Benguela upwelling regime and considerable supply of terrigenous organic matter. The maturation level of the organic matter is low in all samples.