Regional correlation of deposition sequences in the southern Mesozoic marine province, northwestern Nevada
- Rice Univ., Houston, TX (United States). Dept. of Geology and Geophysics
Strata of the Mesozoic marine province of a northwestern Nevada, deposited in subaerial to deep marine environment in a backarc basin, underwent severe deformation during the late Mesozoic. Restoration of stratigraphic relations among constituent volcanic, volcanogenic, carbonate, and continentally-derived siliciclastic rocks has been hampered by sparse biostratigraphic age control. Regional correlation of coeval facies is made possible by coupling depositional sequences with biostratigraphic control in the southwestern Gabbs Valley Range, the southern Shoshone Mountains, and the southern Clan Alpine Mountains, which serve as reference sections for Late Triassic and Early Jurassic ammonite zonation of western North America. Differentiation between regionally significant sequence boundaries and those of limited areal extent is possible only by linking the biostratigraphy and physical stratigraphic relations, such as abrupt vertical transitions in lithology corresponding to large facies changes. Physical stratigraphic relations alone are not adequate for correlation ad indicated by the diachronous initiation of Early to Middle( ) Jurassic deposition in half-graben basins (Dunlap Formation) which locally cloaks eustatically( ) controlled depositional sequences. Within these limitations, three regionally extensive sequences are recognized in the reference sections and have lower boundaries at the base of Upper Triassic shallow marine to deltaic carbonate-clastic rocks (Luning Formation) and at the base and within subtidal to offshore-marine carbonate and clastic rocks (Triassic and Jurassic Volcano Peak Group).
- OSTI ID:
- 5128545
- Report Number(s):
- CONF-9305259-; CODEN: GAAPBC
- Journal Information:
- Geological Society of America, Abstracts with Programs; (United States), Vol. 25:5; Conference: 89. annual meeting of the Cordilleran Section and the 46th annual meeting of the Rocky Mountain Section of the Geological Society of America (GSA), Reno, NV (United States), 19-21 May 1993; ISSN 0016-7592
- Country of Publication:
- United States
- Language:
- English
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