Early Jurassic hydrothermal vent community from the Franciscan complex, San Rafael Mountains, California

Article Abstract:

The Franciscan Complex serves as a tectonic record of the eastward-directed subduction of the Farallon plate along the western margin of the North American craton. In it lies the Figueroa deposit, a large mass of sulfide which preserves the only known Jurassic hydrothermal vent fossils. Most of the specimens found here are low in diversity and are mainly composed of vestimentiferan worm tubes. Tectonic movement in this area is estimated to have occurred sometime between the Jurassic and the Cenozoic era.

Author: Little, Crispin T.S., Herrington, Richard J., Haymon, Rachel M., Danelian, Taniel
California, Fossils, Geology, Stratigraphic, Stratigraphy, Hydrothermal vents

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Synsedimentary deformation in the Jurassic of southeastern Utah-a case of impact shaking: comment and reply

Article Abstract:

Deformation of the Upheaval Dome in Utah has drawn the interest of geologic experts, who expressed contradicting claims over the cause of the phenomenon. Some researchers strongly believe that the deformation was caused by excessive salt solution beneath the structure, which caused irregular uplift of adjacent land areas. Still, others assert that the collapse was probably triggered by impact shaking brought about by the Moab fault.

Author: Chan, Marjorie A., Bridges, L.W. Dan, Alvarez, Walter, Staley, Erick, O'Connor, Diane
Natural history, Plate tectonics, Utah, Sedimentary structures

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Long-term faunal stasis with evolutionary coordination: Jurassic benthic marine paleocommunities, Western Interior, United States: comment and reply

Article Abstract:

Tang et al. do not have any evidence for a 'coordinated pattern in the origin and extinction of species.' The fossils they studied were taken from the Middle and Upper Jurassic period during which there was no known significant events of extinction. They could not show any evidence of short periods of ecological and biological upheavals which determine species extinction as noted by Brett and Baird in 1995.

Author: Ivany, Linda C., Boucot, Arthur J., Schopf, Kenneth M.
Mass extinction, Animals, Fossil, Fossil animals, Paleontology, Mass extinction theory

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Subjects list: Research, Jurassic period, Analysis
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