Crude oils and source rocks from the Northern and offshore depobelts of the Niger Delta basin, Nigeria have been characterized based on the distribution of pyrene and its derivatives by gas chromatography-mass spectrometry. Moreover, the crude oils have been characterized by the dominance of pyrene over fluoranthene while fluoranthene generally predominated over pyrene in the rock samples. Also...

The composition of sediment organic matter (OM) exerts a strong control on biogeochemical processes in lakes, such as those involved in the fate of carbon, nutrients and trace metals. While between-lake spatial variability of OM quality is increasingly investigated, we explored in this study how the molecular composition of sediment OM varies spatially within a single lake and related this vari...

Proposed radioactive waste repositories require long residence times within deep geological settings for which we have little knowledge of local or regional subsurface dynamics that could affect the transport of hazardous species over the period of radioactive decay. Given the role of microbial processes on element speciation and transport, knowledge and understanding of local microbial ecology...

The development of three Tertiary deltaic complexes has resulted in the deposition of up to 10 km of sandstones and shales comprising the sources and reservoirs for crude oils that occur onshore, near-o€shore and, with future exploration e€orts, those likely to be encountered in deepwater reservoirs north of the Brunei coastline. We examined a series of o€shore oils and onshore rock samples in ...

Al Introduction A2 Acknowledgments A2 Gold as a store of wealth the uses of gold A2 How much gold? A2 Factors influencing the price and production of gold A3 The role of gold in world monetary systems A6 Where gold comes from A6 Scope of this series, and conventions used A7 References cited A8 Geochemistry of gold in hydrothermal deposits Abstract A9 Introduction A9 Nature and source of solutio...

1 Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, DC, USA, 2 Department of Earth Sciences, ETH-Zurich, Institute for Geochemistry and Petrology, Zurich, Switzerland, 3 Formerly affiliated with the Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA, 4 Department of Earth Sciences, University of...

In the USSR and in Russia, women predominated among soil scientists despite problems related to field research tundra, taiga, mountains other severe environments. One such woman was Maria Glazovskaya, who worked highlands semi-deserts studying little known soils, both recent relict, primary pedogenesis, geochemical features of hard rock weathering. Her scientific interests were diverse, corresp...

The origin of red or reddish-brown, clay-rich, ‘‘terra rossa’’ soils on limestone has been debated for decades. A traditional qualitative explanation for their formation has been the accumulation of insoluble residues as the limestone is progressively dissolved over time. However, this mode of formation often requires unrealistic or impossible amounts of carbonate dissolution. Therefore, where ...

1575. Hunt, J.M., Philp, R.P. and Kvenvolden, K.A. (2002) Early developments in petroleumgeochemistry. Organic Geochemistry, 33 (9),

Prior research has suggeste d that the source of respirable silica dust in underground coal mines is typically the immediate top or bottom lithology adjacent to the mined seam, not mineral matter bound within the mined coal bed. Geochemical analyses were applied in an effort to identify the specific source rock of respirable quartz dust in coal mines. The analyses also demonstrate the compositi...