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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 46 (1962)

Issue: 2. (February)

First Page: 261

Last Page: 261

Title: Permian Fusulinids in Eastern Nevada--Paleoecologic Implications: ABSTRACT

Author(s): Previous HitHaroldTop J. Bissell

Article Type: Meeting abstract


Field and laboratory studies of fusulinids from exposed Permian strata in no fewer than 15 mountain ranges in eastern Nevada, and six similar sections in western Utah have progressed to the point that the following conclusions can be drawn concerning paleoecology of these Foraminifera: (1) they were most abundant in the infraneritic to epineritic benthos; (2) areas of optima were below wave-base for many schwagerinids, although some of these along with numerous parafusulinids seemingly thrived in areas of high energy; (3) most species of all fusulinids occur in areas where clean calcarenitic limestones and clean carbonate muds accumulated; (4) pseudoschwagerinids and paraschwagerinids lived in environments of agitation as well as under circumstances of slightly foul botto s; (5) triticitids and pseudofusulinids occurred where silty, sandy, and calcarenitic materials were accumulating under moderate- to high-energy conditions; (6) most species of fusulinids can be found in the reef-tract; some in fact contributed notably to this biotope.

Throughout most places in eastern Nevada (and western Utah) strata of Wolfcampian age are limestones of criquinitic, calcarenitic, and high-energy patch-reef types. These contain pseudofusulinellids, schwagerinids, and pseudoschwagerinids in abundance. Strata of Leonardian age consist of silty, sandy, calcarenitic and reef materials, all more or less rich in robust to elongated schwagerinids and parafusulinids; pseudoschwagerinids occur abundantly in reef-rocks. Strata of late Leonardian, and Wordian to early Capitanian age locally are gritty, sandy, conglomeratic, and coarsely bioclastic; diagnostic species of parafusulinids and schwagerinids preferred the environment typifying these sedimentary realms.

It should be emphasized that possibly all these Foraminifera at times and under optimum environmental conditions formed veritable slimes and oozes of protoplasm. Some of this material may have contributed to oil source beds for strong hydrocarbon odors now characterize most fusulinid-bearing strata of the Permian of eastern Nevada and western Utah.

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