Structural Geology of Eastern Part of Richmond and Western Part of Naomi Park Quadrangles, Utah-Idaho
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Utah State University DigitalCommons@USU All Graduate Theses and Dissertations Graduate Studies 5-1975 Structural Geology of Eastern Part of Richmond and Western Part of Naomi Park Quadrangles, Utah-Idaho Arthur J. Mendenhall Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/etd Part of the Geology Commons Recommended Citation Mendenhall, Arthur J., "Structural Geology of Eastern Part of Richmond and Western Part of Naomi Park Quadrangles, Utah-Idaho" (1975). All Graduate Theses and Dissertations. 1917. https://digitalcommons.usu.edu/etd/1917 This Thesis is brought to you for free and open access by the Graduate Studies at DigitalCommons@USU. It has been accepted for inclusion in All Graduate Theses and Dissertations by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. STRUCTURAL GEOLOGY OF EASTERN PART OF RICHMOND AND WESTERN PART OF NAO:MI PEAK QUADRANGLES, UT.A.H-IDAHO by Arthur J. Mendenhall _A thesis submitted in partial fulfillmenf of the requirements for the degree of MASTER OF SCIENCE in Geology Approved: Major Professor Committee Member Committee Member Dean of Graduate Studies UTAH STATE UNIVERSITY Logan, Utah 1975 /," }., 1/ ii ACKNOWLEDGMENTS The writer wishes to acknowledge the assistance of Dr. Clyde T. Hardy who aided in reconnaissance and also in resolving particular problems en- countered during mapping. Hardy, along with Dr. Robert Q. Oaks, Jr., and Dr. Donald R. Olsen, reviewed the manuscript and presented suggestions for its improvement. i The writer also wishes to thank his parents. They provided financial support and encouragement during both the field work and the preparation of the report. Arthur J. Mendenhall iii TABLE OF CONTENTS Page ACKNOWLEDGMENTS ii LIST OF TABLES vi LIST OF FIGURES vii LIST OF PLATES ix ABSTRACT • • • • • • • • • • • • • <I. • • • • • • x INTRODUCTION 1 Purpose and Scope .. 1 Location and Accessibility . 1 Field Work . 3 Previous Investigations 3 STRATIGRAPHIC UNITS ....... 4 Precambrian Rocks 4 Mutual Formation 4 Paleozoic Rocks 5 Brigham Formation •.................... 5 Langston Formation •.................... 7 C a mbrian-De vonian units 9 Tertiary System 9 Salt Lake Formation 9 Quaternary System 15 Boulder deposits 15 Lake Bonneville Group 15 Colluvial deposits 16 Alluvial deposits 16 iv TABLE OF CONTENTS (Continued) Page STRUCTURAL FEA TURES 17 Regional Setting ......................... 17 Folds ..........• • . 19 Logan Peak syncline 19 Minor anticline 20 Bedding-plane Thrust Faults 20 Upper- thrust fault zone ••••••••••• I • ••••••. 20 Lower thrust faults 22 Normal Faults 22 Western normal fault 22 Eastern normal fault 26 Minor normal faults 26 Landslides . .. 31 Major landslide 31 Minor landslides 35 EARTHQUAKE ACTIVITY 37 General Statement 37 Seismic Events 37 STRUCTURAL SYNTHESIS 39 General Statement 39 Sevier Events 39 Major folding . • . • . 39 Bedding-plane thrust faulting ....•........... 40 Basin and Range Events 40 Normal faulting . • . • . 40 Landsliding .........•................. 41 Earthquake activity •..................... 42 v TABLE OF CONTENTS (Continued) Page LITERATURE CITED . 43 vi LIST OF TABLES Table Page 1. Stratigraphic units of Camhrian-Devonian age of the eastern part of the mapped area ............ .. 12 2. Earthquakes of Richmond and Naomi Peak quadrangles, Utah-Idaho, 1850 through June, 1965 (Cook and Smith, 1967) ................................ 38 vii LIST OF FIGURES Figure Page 1. Index map of part of Utah and Idaho showing location of the eastern part of Richmond and western part of Naomi Peak quadrangles, Utah-Idaho .•.............. 2 2. Mutual Formation, in smooth slope on left, underlies Brigham Formation, in cliffs on right, on northern side of the canyon of Cherry Creek; view north ......... 6 3. Brigham Formation, Langston Formation, and overl,ving Camprian formations on northern side of the canyon of Cherry Creek; view north-northeast .......... 10 4. Brigham Formation and overlying Langston Formation between North Fork and South Fork of High Creek; view southeast ............................... 11 5. Bedding-plane thrust fault separates Brigham Formation (€b), on left, from overlying Langston Formation (€1), in central peak, on northern sitle of North Fork of High Creek; view north 21 6. Mutual Formation (p6m), on left, underlies Brigham Formation (€b), on right, on northern side of the canyon of High Creek; view north .................. 23 7. Mutual Formation, on right, underlies Brigham Formation, in cliffs on left, on southern side of South Canyon; view south ............................ .... 24 8. Eastern normal fault, along mountain front, north of High Creek; view northeast ...................... 27 9. Eastern normal fault, along mountain front, south of High Creek; view east ......................... 28 10. Eastern normal fault, at mountain front, on southern side of High Creek; view south .................. 29 11. Minor normal faults in north fork of Cherry Creek; view northeast 30 viii LIST OF FIGURES (Continued) Figure Page 12. Major landslide of St. Charles and Garden City Formations on southern side of Nebo Creek; view southwest ........ 32 13. Major landslide of St. Charles (€sc) and Garden City (Ogc) Formations on northern side of Nebo Creek; view northwest 33 ix LIST OF PLATES Plate Page 1. Geologic map of eastern part of Richmond and western part of Naomi Peak quadrangles, Utah-Idaho . ... In pocket 2. Structure sections of eastern part of Richmond and western part of Naomi Peak quadrangles, Utah-Idaho ..... In pocket x ABSTRACT Structural Geology of Eastern Part of Richmond And Western Part of Naomi Peak Quadrangles, Utah-Idaho by Arthur J. Mendenhall, Master of Science Utah State University, 1975 Major Profes sor: Dr. Clyde T. Hardy Department: Geology The mapped area, which includes the eastern part of the Richmond and the western part of the Naomi peak quadrangles, Utah-Idaho, is located in the central part of northern Utah and southeastern Idaho. It is located along the eastern side of Cache Valley and western side of the Bear River Range. Cache Valley is in the Basin and Range province and the Bear River Range is in the Middle Rocky Mountain province. The mapped area is about 8.6 miles long, in the north-south direction, and 7.8 miles long, in the east-west direction. The Mutual Formation of Precambrian age is the oldest stratigraphic unit exposed in the mapped area. It consists of purple and brown quartzite. The Brigham Formation of Early Cambrian age and the Langston Forma tion of Mid- dIe Cambrian age overlie the Mutual in stratigraphic succession. The Salt Lake Formation of Tertiary age unconformably overlies older rocks; it is also faulted against the Mutual Formation. A major landslide of Precambrian, Cambrian, xi and Ordovician formations is present in the southern part of the mapped area. It is unconformably overlapped by the Salt Lake Formation. The Lake Bonne- ville Group of late Pleistocene age is present in Cache Valley and overlaps older rocks along the western side of the Bear River Range. The Precambrian and Cambrian stratigraphic units, except for those of the landslide, dip eastward and form the western flank of the Logan Peak syn- cline. A small disharmonic asymmetrical anticline, in the Langston and Ute Formations of Cambrian age, indicates eastward movement. Two bedding- plane faults locally eliminate the basal Naomi Peak Limestone Member of the Langston Formation. A major normal fault, which is nearly vertical, extends along the base of the Bear River Range. Another normal fault, which is probably nearly vertical, parallels the western edge of the foothills. The folding and bedding-p[ane thrust faulting involve eastward move- ment and occurred during the Sevier orogeny. This orogeny began during late Jurassic time and extended into the early part of the Tertiary Period. Basin and Range normal faulting began early in the Tertiary Period. The normal faults produced great relief between Cache Valley and the Bear River Range. The landslide surface is thought to have formed as a west-dipping thrust fault. Reversed movement on this fault, due to removal of support on the valley side, produced the major landslide. (58 pages) INTRODUCTION Purpose and Scope The object of this investigation is to improve understanding of the struc- tural features of a limited area in the central part of northern Utah and south- eastern Idaho. The geologic map and structure sections are in greater detail than previous ones (Plate 1 and 2). Location and Accessibility The mapped area is located in the central part of northern Utah and southeastern Idaho (Figure 1). It consists of the eastern two-thirds of the Richmond quadrangle, Utah-Idaho: and the adjoining western half of the Naomi Peak quadrangle, Utah-Idaho. These quadrangles are 7. 5-minute topographic maps published by the U. S. Geological Survey. The northern boundary of the mapped area is less than 0.1 mile north of the Utah-Idaho state line and the southern boundary is about 8.6 miles south of the same state line. The area is about 8.6 miles long, in the north-south direction, and 7.8 miles wide, in the east-west direction. Features of importance are easily accessible. Major canyons have roads or trails that can be reached from U. S. Highway 91. 2 IDAHO UTAH • NAOMI PEAK en 9980 (I) en ;z; o 5 10 __ :3EL~~======~i t.Il.ES Figure 1. Index map of part of Utah and Idaho showing location of the eastern part of Richmond and western part of Naomi Peak quadrangle s, Utah-Idaho. 3 Field Work The field work was conducted during the summer and fall of 1973. The geologic features were mapped on aerial photographs and this information was later transferred to a topographic base at a scale of 1:12,000. Previous Investigations The first detailed investigation of the Richmond and Naomi Peak quad- i rangles, Utah-Idaho, was made by Bailey (1927a, 1927b). The next study was a thesis by Maxey (1941) that summarized Cambrian stratigraphy of the region. Peterson (1946) investigated the ground water of Cache Valley. A general geologic map, prepared by Williams (1948, Plate 1), including the Richmond and Naomi Peak cpadrangles, Utah-Idaho.