GEOLOGY YOUNG STUDIES UNIVERSITY CONTENTS Paleontology and Depositional Environments: Cambrian of Western North America A symposium U. J. Brady University of Kansas D. P. Campbell University of Kansas H. E. Cook U. S. Geological Survey W. H. Fritz Canadian Geological Survey J. C. Kepper University of Nevada, Las Vegas R. B. Koepnidc Williams College V. E. Kurt2 Southwest Missouri State University K. C. Lohmann State University of New Yo&, Stony Brook D. J. McSride University of Kansas J. N. Moore University of California, Los AngeIes A. R. Pher State University of New York, Stony Brook J. K. aigby Brigham Young University R. A. Robison University of Kansas A. J. Bowell University of Kansas James Sprinkle University of Texas, Austin M. E. Taylor u. s. Geological SULV~~ Extended presentations of some papers presented at a Paleontological Society symposium held in Salt Lake City, Utah, on October 20, 1975. Brigham Young University Geology Studies Volume 23, Part 2-July 1976 Contents Trilobites in Utah folklore ................ M. E. Taylor and R. A. Robison Lower Cambrian Stratigraphy, Mackenzie Mountains, Northwestern Canada .................................................... W. H. Fritz Depositional Environments of the Lower Cambrian Poleta Formation and Its Stratigraphic Equivalents, California and Nevada ............................ J. N. Moore Biostratigraphic Implications of Trilobite Biofacies: Albertella Zone, Middle Cambrian, Western United States ............................ A. R. Palmer and D. P. Campbell Some Observations on Occurrences of Cambrian Porifera in Western North America and Their Evolution .......................................................... J. K. Rigby Biostratigraphy and Paleoecology of Cambrian Echinoderms from the Rocky Mountains ................ James Sprinkle Stratigraphic Relationships and Depositional Facies in a Portion of the Middle Cambrian of the Basin and Range Province ................................ J. C. Kepper Middle Cambrian Trilobite Biostratigraphy of the Great Basin ..................................................... R. A. Robison Lower Dresbachian (Upper Cambrian) Platform-to-Basin Transition in Eastern Nevada and Western Utah: An Evaluation through Lithologic Cycle Correlation .... K. C. Lohmann Depositional History of Upper Dresbachian-Lower Franconian Pterocephaliid Biomere from West-Central Utah ........................................... R. B. Koepnick Outer Shelf Communities and Trophic Groups in the Upper Cambrian of the Great Basin ....................... D. J. McBride An Upper Cambrian Subtidal Blanket Carbonate, Eastern Great Basin ........................... M. J. Brady and A. J. Rowell Brachiopods and Biomeres .................... A. J. Rowell and M. J. Brady Continental Shelf and Slope Facies in the Upper Cambrian and Lowest Ordovician of Nevada ........................................ M. E. Taylor and H. E. Cook Biostratigraphy of the Cambrian and Lowest Ordovician, Bighorn Mountains and Associated Uplifts in Wyoming and Montana ............................................... V. E. Kurtz A publication of the Department of Geology Brigham Young University Provo, Utah 84602 Editor W. Kenneth Harnblin Issue Editors R. A. Robison A. J. Rowel1 Brigham Young University Geology Studres is published semiannually by the department. Geology Studies consists of graduate student and staff research in the department and occasional papers from other contributors. Sttddies for Students supplements the regular issues and is intended as a series of short papers of general interest which may serve as guides to the geology of Utah for beginning students and laymen. ISSN 0068-1016 Distributed July 30, 1976 Price $5.00 (Subject to change without notice) 4-77 400 26481 EDITORIAL PREFACE Prior to the last decade, the large majority of Cambrian studies in west- ern North America were concerned with either stratigraphy or systematics of trilobites. A new phase of Cambrian investigations commenced about a decade ago with expanded interest in not only stratigraphy and trilobites, but many other types of organisms, depositional environments, facies rela- tionships, paleoecology, evolution, and other topics. Of particular significance is a marked increase in cooperation between paleontologists and sedimentolo- gists to better present an integrated analysis of Cambrian faunas and their environments. Because favorable cllmate and structure interact to provide ex- cellent outcrops in numerous mountain ranges, much of this new work has been concentrated in the Great Basin of eastern and southern Nevada, western Utah, and parts of adjacent California and Idaho. The idea of a symposium to summarize thls new Cambrian work was first discussed by A. R. Palmer, R. A. Robison, and M. E. Taylor during 1972 and resulted in a Paleontological Society symposium that was convened in Salt Lake City, Utah, on October 20, 1975. Limits of a one-day session allowed for presentations by probably less than half of those qualified to participate. However, the program is judged to be representative of the problems being investigated and the results being obtained. This volume contains 14 of the 22 papers read at the symposium. Some of the papers that were read are being published elsewhere. For a variety of other reasons, some of the symposium partrcipants were unable to contribute to this volume. The reader is referred to volume 7, number 7, of the 1975 Geological Society of America Abstracts with Programs for a complete list of symposium topics (p. 922-923) and abstracts. One short paper, "Trilobites in Utah Folklore," although not read at the syrnposlum, has been added here be- cause it concerns Elrathza kingii, which is probably the most widely known of all Cambrian fossils. The diversity of subject matter covered in the total of 15 papers is obvious, and it is hoped that from the seemingly autonomous approaches, the reader will gain a general feeling of the new era of Cambrian investigation. Several of the papers in this volume are concerned with areas in western Utah that are covered by a series of excellent geologic maps and stratigraphic columns that have been prepared by L. F. Hintze. Readers may well benefit by reference to these 15-minute quadrangle maps, which were published in 1974 as U. S. Geological Survey Miscellaneous Field Stud~esMaps MI;-633 to 637. Professor Hintze has additional maps in preparation. We acknowledge with gratitude the aid of J. K. Rigby and W. K. Hamb- lin in arranging for publication of these syn~posiumpapers. Funds for much of the miscellaneous cost of organizing thrs volume were provided by the Department of Geology, University of Kansas. Flnally, we appreciate the cordial and prompt cooperation we received, without exception, from each of the contributors. Lawrence, Kansas R. A. Robison March 1976 A J. Rowell Trilobites in Utah Folklore MICHAELE. TAYLOR~AND RICHARDA. ROBISONZ 'U.S. Geological Survey, Wa.shing;on, D.C. 20244 'University oof Kansas, Lawrence 66045 INTRODUCTION Well-preserved specimens of Elrathia kijzgii (Meek) are found in the Wheeler Formation of Middle Cambrian age east of Antelope Spring in the Wheeler Amphitheater, House Range, Millard County, Utah (Text-fig. 1 ) . The species is common in western Utah (Robison, 1964), but the locality at Antelope Spring is unique in yielding articulated, dark-colored dorsal exo- skeletons having thick deposits of fibrous calcite on the under surfaces (Bright, 1959). The secondary calcite strengthens the fossil so that specimens weather free or are easily extricated from the rock matrix. Great abundance, fine degree of preservation, and ease of removing speci- mens from the matrix have resulted in Elrathia kingii becoming popular among both professional and amateur fossil collectors. Photographs of Elrathia kingii from the Wheeler Amphitheater have been widely published in textbooks, and commercial demands are currently sufficient to support a small private quarry- ing operation. The trilobite is popular among rockhounds, a situation un- doubtedly stimulated by several popular articles on fossil collecting at the Wheeler Amphitheater (for example, Beckwith, 1931; Robison, 1970; Dicker- son and Dickerson, 1972). Some historical records suggest that Elrathia kilzgii was collected at the Wheeler Amphitheater and fabricated Into amulets by the Pahvant Ute Indians from Sevier Valley, Utah. The story provides an Interesting sidelight to studies of Cambrian trilobites from the Great Basin. BECKWITH'S NECKLACE Frank Asahel Beckwith lived in Delta, Utah, from 1913 until his death in 1951. Mr. Beckwith, a banker, later the editor of the Millard County Chronicle, spent much of his free time roaming the desert regions of western Utah study- ing the geology and history of the local Indians-the Pahvant Utes. Despite a lack of college training, he *was an accon~plishednatural historian. Beckwith was familiar with the more common local fossils, having served as guide for Charles E. Resser, Teiichi Kobayashi, Riuji Endo, and other geologists who occasionally visited western Utah on collecting trips. Out of respect for Beckwith's prowess as a fossil collector, Charles E. Resser, Smith- sonian Institution, named the Middle Cambrian merostome Beckzuithia typa after him in 1931. Upon his death, Beckwith left a substantial personal library, a large col- lection of fossils, Indian artifacts, photographs, and voluminous notes on ob- servations made during his travels. The narrative that follows is based largely upon information from an