Characteristics of Cretaceous Organic Matter in the Atlantic
Published:January 01, 1982
Drilling in the Atlantic Ocean basin has revealed large quantities of organic matter throughout Cretaceous strata. The organic-rich deposits in the North Atlantic do not appear to be genetically related to those in the South Atlantic. There are clear differences in the character of the organic matter and its possible origins. The contrast in type of organic matter preserved in Cretaceous strata from the North and South Atlantic can be explained by continental drainage patterns and evolutionary stages of ocean basin development. During the Early Cretaceous, a less evolved, much more restricted South Atlantic exhibited conditions favorable to production and preservation of marine organic matter. This is in contrast to the more evolved, more open North Atlantic throughout the Cretaceous, and the Late Cretaceous South Atlantic. This evolutionary development of Atlantic passive margins aids in explaining the observed distribution of oil and gas discoveries.
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Studies in Continental Margin Geology
"Studies in Continental Margin Geology" contains papers from a research conference co-sponsored by AAPG and the University of Texas Institute for Geophysics held in Galveston, Texas in 1981. Rapid advances in the understanding of continental margin geology were taking place during the time period, based on major improvements in the quality and availability of regional seismic surveys plus other fields such as organic geochemistry. For the first time it was becoming common to have a visual characterization of tectonic processes at significant depths below the surface. Twenty-seven papers are presented that deal with field investigations of continental margin structure and stratigraphy. The geographic areas of study are global in nature and many of the descriptive results are derived from modern seismic investigations in areas where that type of data had not previously been available in commercial publications. Fifteen of the papers focus on rifted margins and the other twelve concern convergent margins. Twelve papers are model investigations of a variety of margin environmental processes, related to subjects such as depositional environments, biostratigraphy, organic matter deposition, and oil and gas occurrences as a function of the plate tectonic setting. An additional nine papers model the thermal and mechanical tectonic processes involved in the structural development along continental margins.