BRIGHAM YOUNG UNIVERSITY GEOLOGY STUDIES Volume 27, Part 3 CONTENTS Studies for Students #lo, Geologic Guide to Provo Canyon and Weber Canyon, Central Wasatch Mountains, Utah ..................................................................................................................................... ames L. Baer and J. Keith Rigby The Rate of Sedimentation in Utah Lake and the Use of Pollen as an Indicator of Time in the Sediments ...................................................................................................................................................................... ess R. Bushman Structure and Stratigraphy of the Rex Peak Quadrangle, Rich County, Utah ............................................................................................................................. Randy L. Chamberlain The Geology of the Drum Mountains, Millard and Juab Counties, Utah ...................................................................................................................................................... Martin L. Dommer Geology of the Fairview Lakes Quadrangle, Sanpete County, Utah ................................................................................................................................................ Gary G. Oberhansley Geology of the Virgin River Gorge, Northwest Arizona ........................................................................................................................................................... Douglas A. Steed Geology of the Blue Mountain Quadrangle, Beaver and Iron Counties, Utah .................................................................................................................................................... Clark L. Weaver Publications and Maps of the Department of Geology Cover: Aenal photo of Utah Valley and surroundtng area. A publication of the Department of Geology Brigham Young University Provo, Utah 84602 Editors W. Kenneth Hamblin Cynthia M. Gardner Brigham Young University Geology Studies is published by the Department of Geology. This publication consists of g-raduate student and faculty research within the depart- ment as well as papers submitted by outside contributors. Each article submitted by BYU faculty and outside contributors is externally reviewed by at least two qualified persons. ISSN 0068-1016 Distributed December 1980 12-80 525 49696 Geology of the Fairview Lakes Quadrangle: Sanpete County, Utah* GARYG. OBERHANSLEY Texaro 1570 Grant Sfreef P.O.Box 2100 Denver, Colorado 80201 A8smm.-The Faitvim Lakes Quadnngle is located in the northern Wasatch Location and Accessibility Plateau. The astern third of the quadrangle is included in the northern Wasatch Plateau coalfield, which has considerable reserves in the Blackhawk The Fairview Lakes Quadrangle lies entirely within the Formation. Wasatch Plateau in Sanpete County, central Utah. The central Approximately 1,050 m of Late Cretaceous and Early Tertiary rocks are ex- part of the quadrangle is approximately 22 km east of Fairview, pod. The oldest exposed unit is the Blackhawk Formation, which accumu- which is in the northern Sanpete Valley, about 86 km south- lated in floodplain and coastal plain environmenrs rhar once bordered the Man- east of Provo, Utah, on U.S. 89 (fig. 1). cos Sea. Thcsc diments were derived from Cretaceous Sevier orogenic uplands to the wet. Thick sandstone and conglomerate of the Castlegate Sandstone and An extensive network of maintained and unimproved roads thick sandstone and minor interbcdded shale and conglomerate of the overlying branching from Utah 31, which cuts across the southwestern Price River Formation accumulated in the subsiding forcdeep basin. Variegated part of the quadrangle, covers the mapped area. However, be- mudstone and fluvial sandstone of the North Horn Formation were deposited cause the area is at high elevations, road access into remote on asrward extending CretaceousTertiary floodplains. Nonmarine limestone and thin layen of coal occur in the lacustrine middle pan of the formation. areas off the main highway is possible only during summer and More extensive lacustrine development is recorded in the Flagstaff Limestone. early fall months after the heavy snowfall has melted and roads Regional uplift in middle to late Tertiary time elevated the area of the have dried out. Permission to cross private land must be ob- Wasatch Plateau and formed the Wasatch Monocline. High-angle normal faults tained from local owners. and grabens developed with nearly north-south trends, possibly a result of salt removal from Jurassic beds at depth and collapx of the overlying units or of ba- Field Methods sin-and-range faulting. The largest of these fault systems is the Gooseberry Gra- bcn, which has approximate displacement of 350 m on the downdropped cen- Fieldwork began in June and was completed by September tral block. 1979. Faults, stratigraphic contacts, and other features were Faulting in the astern part of the quadrangle has resulted in drainage diver- plotted on aerial photographs at a scale of 1:15,000. Stratigra- son in Flat Canyon and Brooks Canyon. Beheaded canyons and barbed tributary phic sections were measured with a 15-m tape. A Brunton com- drainage are well shown. pass and Abney level were used for determination of bedding Late Pleistocene (Pinedale) valley glaciers eroded well-dweloped cirques attitudes and slope angles. The Wentworth scale was used for and produced glacial moraines in a few northeastward-draining canyons and in grain and clast size, and the rock-color chart, published by the the high southem valley of the Gooseberry Graben. Geological Society of America, was used as a standard color hnd surface instability is primarily confined to slopes underlain by the North Hom Formation. The stceDness of slo~csand the material uDon which guide. roads, rcxrvoirs, and homes are built need to bc taken more into consideration in future land management. INTRODUCnON The eastern third of the Fairview Lakes Quadrangle is in- cluded in the northern Wasatch Plateau coalfield and contains 39045' important coal reserves in the Blackhawk Formation. This part of the coalfield is expected to gain more importance as the de- mand for coal increases and as the easy-to-mine reserves in other areas are depleted. Interest in possible petroleum accumulations in the Wasatch Plateau increased after discovery of natural gas in Car- bon and Emery Counties. It resulted in drilling on two struc- tures within the quadrangle, neither of which was productive in the Cretaceous section tested. However, lower formations that produce east of the plateau remain untested and may be of significant value. Although the southwest part of the quadrangle had been mapped previously by Pashley (1956), as part of his study of ge- ology of the western monoclinal flexure of the Wasatch Plateau, no recent detailed mapping of the Fairview Lakes Quadrangle had been done. An interest in coal and in possible petroleum and natural gas in this area prompted this more de- 39'30' tailed investigation of the geology in the quadrangle. FIGURE].-Index map of Fairview Lakes Quadrangle. *A thesis pranud to the Dcp~mncntof Ccolosl. Brigham Yarng Univcdcy, in partial fulfillmrnr of rhc rquirrmrnrr for rhc dcgra Mvvr of Science, April 1980. Their chirmm: J. K. Rigby. 7 3 74 G. G. OBERHANSLEY Fossils were collected to help in determining age relation- stone, shale, and coal and occurs between the underlying Star ships and environments of deposition from each formation, but Point Sandstone and the overlying Castlegate Sandstone. they came principally from the Flagstaff Limestone and the The Blackhawk Formation is extensively exposed along the North Horn Formations. Samples of the Flagstaff Limestone east side of the Wasatch Plateau, and eastward into the Book were collected from several sites in the area. These sites were Cliffs region (Doelling 1972, p. 4). The formation is also ex- evaluated as possible sources of limestone for construction ag- posed on the western flank of the Wasatch Plateau, for ex- gregate, road metal, and raw material for manufacture of rock ample, in the canyon between Spring City and Mt. Pleasant dust. Samples were submitted to the Utah Geological and Min- and farther south in Twelve Mile Canyon and Salina Canyon eralogical Survey for analysis. (Pashley 1956, p. 13). The area of outcrop in the Fairview Previous Work Lakes Quadrangle is in canyons cut into the flat upland east of the Gooseberry Graben in the eastern part of the quadrangle The southwest part of the Fairview Lakes Quadrangle w-as (fig. 19). mapped in reconnaissance fashion by Pashley (1956). The re- In the Fairview Lakes Quadrangle, the Blackhawk Forma- gion to the east of the quadrangle was mapped by Spieker tion is commonly covered with soil and slope wash, with only (1931). Stratigraphic nomenclature of the area is based upon occasional thick, resistant sandstone beds exposed. The forma- early studies by Spieker and Reeside (1925). Some revisions tion is almost entirely concealed by soil and alluvium near the were made by Spieker (1946) and Fisher, Erdmann, and Reeside bottom of the prominent eastern wall of the Gooseberry Gra- (196"). ben. The best exposure of the formation within the quadrangle Walton (1955) published a regional study on the Wasatch is in the canyon of Gooseberry Creek in section 29, T. 12 S, R. Plateau gas fields and outlined the major faults and folds of the 6 E, but even this outcrop is restricted to scattered sandstone Wasatch Plateau.