ABSTRACT: Ameasured section of the Upper Pennsylvanian-Lower Permian Riepe Spring Limestone at Spruce Mountain Ridge, Elko County, Nevada, presents a stratigraphic record of the coastal evolution and the shoreline-to-openmarine depositional history of a portion of the post-Antler foreland. The 420 m thick â€œNorth Spruce Mountain Ridgeâ€ (NSMR) section consists of highly variable lower Missourian (Upper Pennsylvanian)-uppermost Wolfcampian (Lower Permian) strata. The NSMR section, which follows Section 1 of Hope (1972), was remeasured and sampled by the authors for stratigraphic revision of the Hopeâ€™s Section 1 with an accompanying biostratigraphic study of the fusulinid and conodont assemblages. As a result, a new lithostratigraphic interpretation of the Riepe Spring Limestone at Spruce Mountain Ridge, consisting of three lithologically distinguishable informal members, is presented herein. The so-called lower, middle, and upper informalmembers of the Riepe Spring Limestone are primarily composed of thick, alternating units of limestone, calcareous sandstone, and quartzose conglomerate. The mixed carbonate-siliciclastic strata of the NSMR section are biostratigraphically constrained by a fusulinid succession comprising eight assemblage zones (lowest to highest stratigraphically): Eowaeringella assemblage zone; Triticites preoryziformis n. sp. assemblage zone; Triticites cf. jacksboroensis assemblage zone; Triticites cullomensis-Dunbarinella kauffmani assemblage zone; Triticites creekensis-Triticites pinguis assemblage zone; Schwagerina wellsensis assemblage zone; Eoparafusulina linearis assemblage zone; Schwagerina franklinensis-Schwagerina nowitzkii n. sp. assemblage zone. Fusulinid collections include specimens from new field samples and loaned material from the Smithsonian National Museum of Natural Historyâ€™s Douglass-Henbest collection. Descriptions of 39 species are provided, including two species of Eowaeringella, 14 species of Triticites, three species of Pseudofusulinella, one species of Dunbarinella, one species of Douglassites, one species of Schubertella, one species of Pseudofusulina, two species of Cuniculinella, seven species of Schwagerina, three species of Alaskanella, two species of Pseudoschwagerina, one species of Eoparafusulina, and one species of Leptotriticites. New early Missourian-lateWolfcampian taxa described herein include Eowaeringella nevadaensis n. sp., Eowaeringella riepensis n. sp., Triticites contrariatheca n. sp., Triticites postspringvillensis n. sp., Triticites preoryziformis n. sp., Pseudofusulinella wahlmani n. sp., Cuniculinella hiatus n. sp., Schwagerina celeris n. sp., Schwagerina margerumi n. sp., Schwagerina nowitzkii n. sp., Alaskanella hopei n. sp., Alaskanella lata n. sp., and Leptotriticites nevadaensis n. sp.
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