Transgressive reef sequences of the Devonian Devils Gate Limestone, Red Hill, Nevada
- Univ. of California, Santa Barbara, CA (United States). Dept. of Geological Sciences
- Northern Arizona Univ., Flagstaff, AZ (United States). Dept. of Geology
- Humboldt State Univ., Arcata, CA (United States). Dept. of Geology
The Devils Gate Limestone at Red Hill, Simpson Park Range, Eureka Co., Nevada is composed of several conformable transgressive sequences cropping out in a series of step-like cliffs 1--5 m high. The general sequence is as follows: (1) a 1--4 m thick in situ boundstone dominated by large, period rugosans, domical and stratiform stromatoporids and rare, 1--3 cm diameter oncolites. Most of the boundstone is composed of small, cylindrical fossils. Petrographic observation revealed them to be mostly Amphipora and Cladopora. The upper portions of these units are packstones composed of Amphipora/Cladopora and, to a lesser degree, small favositids, round stromatoporoids (3--4 cm diameter), and rip-up clasts. (2) These beds grade upward into a thinly laminated and/or cross-bedded unfossiliferous mudstone. (3) Stratigraphically above the mudstone or in contact with the packstone, is a cross-bedded and/or bioturbated wackestone containing fossils no greater than 2 mm. In thin section, the mottled reddish-grey wackestone is pelletal, with rare lenses of small crinoid columnals. Disarticulated brachiopod shells of low diversity are found near the tops of some of these layers. Community dominance in the reefal units alternates between Amphipora/Cladopora, colonial rugose, and stromatoporoids. Oncolite mounds are common in the uppermost unit. The typical reef succession consists of domical and digitate stromatoporoids growing on the upper surfaces of in place or disturbed, large rugosans, though the reverse has been noted. Tabulate corals encrusted by stromatoporoids are often found in the packstone. It is important to note that often these successions' can be attributed to juxtaposition along styolites.
- OSTI ID:
- 5021946
- 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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