General Statement A detailed study of the southwestern part of the Randolph quadrangle was undertaken in view of the fact that Richardson (1941) mapped a large area of undifferentiated Ordovician rock. Therefore, the purposes of this investigation are: (1) to prepare a more detailed geologic map of the south­western part of the Randolph quadrangle (Plate 1), (2) to describe the struc­ture, stratigraphy, and geologic history of the area, and (3) to relate the geology to adjacent areas. The elevation of the area mapped ranges from approximately 8, 910 to 6, 700 feet above sea level with the major part of the area above 8, 000 feet. This area forms part of the eastern ridge of the Bear River Range (Williams, 1948, p. 1, 125-1, 126). The southern boundary of the area extends east from the southwest corner of the Randolph quadrangle for a distance of about 4 miles. The eastern boundary extends northward about 11 miles and is parallel to the mountain front. The northern boundary is less well defined and is taken as the ridge separating Curtis Creek from the next canyon to the north. The western boundary extends south approximately 10 miles to the southwest corner of the Randolph quadrangle. The southwestern part of the Randolph quadrangle (Figure 1) covers approximately 56 square miles and lies approximately 60 per cent in Cache County and 40 per cent in Rich County. The major part of the area lies within the Cache National Forest. The area mapped is generally accessible from mid-June to mid- September. A road is maintained along the length of the area by the U. S. Forest Service and is passable by automobile except during heavy rain- storms in the summer months. Field Work The field work was done during the summer of 1963. Formation con- tacts, attitudes, and faults were mapped in the field on aerial photographs of the approximate scale 1:20, 000. This information, concerning the south- western part of the Randolph quadrangle, was transferred to a base map constructed from the topographic map of the U. S. Geological Survey of the same area (1912 edition). The base map was enlarged to the scale 1:24, 000. Stratigraphic sections were measured with a 50-foot steel tape. A Brunton compass was used to measure attitudes and slope angles. Sample rock types were collected from each unit and compared with the rock-color chart (Goddard, 1951) to obtain standard color names. Fossils were collected and identified in the laboratory by the author. Previous Investigations The earlier geologic reports from the general area of the Randolph quadrangle are found in the Hayden Survey and the survey of the Fortieth Parallel supervised by King. Hayden (1871, p. 150-156), Peale (1877, p. 573-609), Hague (1877, p. 393-442), and Emmons (1877, p. 326-393) all commented upon the general area. Walcott (1908) studied the Cambrian rocks of the Bear River Range and defined eight formations. Veatch (1907) studied the area adjacent to the Randolph quadrangle in Wyoming. In the Randolph quadrangle, Richardson (1913) divided the Ordovician rocks into three formations, identified the Silurian rocks as a formation, defined one Mississippian formation, and later (1941) published a geologic map of the quadrangle. Mansfield's (1927) study of southeastern Idaho provided valu­able information concerning regional structure and stratigraphy. Williams (1948) mapped the Logan quadrangle which is adjacent to the area on the west. Specific studies (Ross, 1949, 1951; Maxey, 1941, 1958) have given more detailed information concerning Cambrian and Ordovician rocks of the area. A recent publication by Armstrong and Cressman (1963) is important in dating the uplift and thrust faulting in the ancestral Bear River Range. The Geologic Map of Utah (Stokes, 1961) followed the interpretaion of Richardson (1941), for the southwestern part of the Randolph quadrangle, except in the designation of the Wasatch formation which is shown as Knight conglomerate.

In 1948 Williams subdivided the Jefferson Formation of northeastern Utah into two formations. The upper formation was referred to as the Late Devonian Jefferson Formation and the lower formation the Early Devonian Water Canyon Formation (Williams, 1948, p. 1138). Since that ti.me detailed study of the Water Canyon Formation has not been made . It is the purpose of this investigation to describe in detail the lithology and paleontology of the formation and their implication as to the environment of deposition of Early Devonian time in northeastern Utah.

This dissertation examines how turbidity currents interact with submarine channels. Turbidity currents display exaggerated super-elevation at the outer banks of channel bends, because they have low excess densities relative to the ambient sea-water. Low-velocity zones form where flows separate from the inner banks. In a high-resolution seismic volume, I mapped 226 inclined surfaces associated with bank-attached bars in 16 channel bends of 2 buried sinuous channels. Position and geometries of bars indicate construction from suspended sediment in flow separation zones. Concave-bank benches, first identified in rivers where they are built from fully-suspended sediment deposited within flow separation zones in channel bends, comprise approximately 19% of this dataset. Bars have high median slopes (10°-11°) and occupy less than 30% of channel width. Associated channels migrated a median distance of less than 70% of the channel width and incised 20-30% of the channel depth. These bars are therefore interpreted to have formed during sediment bypass or weak erosion. I have analyzed the sedimentology and stratigraphy of a well-exposed channel complex, in the Permian Brushy Canyon Formation, west Texas. A steeply-inclined set of fine-grained sandstone beds (median dip=10°) at the margin of the channel complex is interpreted as deposits of a bank-attached bar. Beds are characterized by sub- to super-critically climbing ripple-lamination, planar stratification and trough cross-stratification. Paleo-transport directions are at high angles, 20-120°, to the dip azimuths of interpreted bar surfaces. Geometries of bounding surfaces, sedimentation styles and grain-size data were used to construct a facies model for suspension-dominated, bank-attached bars, built within flow-separation zones in submarine channels. I designed physical experiments to examine how erosional turbidity currents evolve channel- bend topography. Time-lapse bathymetry maps capture the evolution of raised benches tied to sedimentation within flow separation zones and erosion outside of separation zones. Erosional currents showed sensitivity to local conditions. The pattern of erosion was connected to roughness elements such as bend curvature and scours on the bed. Turbidity current run-up at the outside of bends produced a greater aerial extent of side-wall erosion than is commonly seen in incisional rivers.

No description available.

Thesis (M. S.)--Stanford University, 1998. / Maps and cross-section on 2 folded leaves in pocket. Submitted to the Department of Geological and Environmental Sciences. Copyright by the author.

General Statement The Summer Ranch and North Promontory Mountains have not been studied in detail geologically, although the surrounding mountains have been extensively investigated. Within the limits of this area, sedimentary rocks of Mississippian through Permian crop out. Sedimentary and volcanic rocks of Tertiary age are also exposed. Extensive Lake Bonneville deposits underlie the valleys and overlap the foothills. The purposes of this study are: (1) to describe the structure, stratigraphy, and geologic history of the area, (2) to prepare a geologic map of the area, and (3) to relate the stratigraphic features of this area to those of the surrounding region. Location of Area The area studied is bordered on the north by the Utah-Idaho state line and on the east by Blue Creek Valley. Utah State Highway 83 and Great Salt Lake form the southern boundary and Curlew Valley, south-southwest from Snowville, Utah, defines the western limit (Figure 1). The mapped area lies completely .within Box Elder County and covers a total of about 529 square miles. The Utah division of the Thiokol Chemical Corporation is located near the southeast corner of the mapped area. Field Work Initial field work was begun in August of 1960. Investigation of the 3 mapped area plus near-by areas was carried on continuously through September of that year and intermittently until June, 1961. Access roads are mainly unimproved but are passable by passenger car. Water is available at most of the ranches in the adjoining valleys and at several springs in the North Promontory and Summer Ranch Mountains. Structural and stratigraphic details were plotted on vertical aerial photographs in the field. Information was subsequently transferred to a topographic map at a scale of 1:62, 500, which was enlarged from a U. S. Geological Survey map, then traced on a transparent overlay. Stratigraphic sections were measured with a Brunton compass or with a steel tape. Previous Investigations No previous complete geologic investigation has been made of the area covered by this report. Various local features within the mapped area have been studied. Walter (1934, p. 178-195) describes the structural relations of the Hansel Valley earthquake of 1934. Additional investigation concerning the structure of Hansel Valley was conducted by Adams (1938). Tertiary stratigraphy of Cache Valley was studied by Adamson (1955). Adamson reported the occurrence of tuffaceous rocks, similar to those in Cache Valley, in association with basalt flows near Snowville, Utah. Smith (1953, p. 74) diagrams the southern limit of the Snake River basalt flows and showed that they covered the northern part of the area concerned in the present investigation.

Rocks of Paleozoic, Tertiary, and Quaternary age are represented in the northern part of the Malad Range. The Paleozoic rocks are represented by thirteen formations that are characterized lithologically by quartzites, shales, and carbonates. The oldest formation in the mapped area of Paleozoic age is the Brigham Formation, and the youngest formation is the Jefferson Formation of late Devonian age. The rocks of Tertiary age are conglomerates, shales, and limestones and are represented by the Wasatch Formation, the Salt Lake Formation, and boulders. Quaternary rocks include sediments of the Lake Bonneville Group and alluvium. The faults in the mapped area were formed during two periods of movement. The east-west-trending faults, northeast-trending faults, and northwest-trending faults are a consequence of compressional forces during Laramide orogenic activity. The north-south-trending faults were the result of Basin and Range block faulting during middle and late Tertiary times.

Nearly 550 samples of fine grained carbonates, collected every 0.5 to 1.0 m from the Bloom Member of the Snaky Canyon Formation at Gallagher Peak, Idaho, were analyzed to determine the high-resolution carbon isotope stratigraphy. To constrain for diagenesis, thin sections were petrographically analyzed and viewed using cathodoluminescence microscopy. Chemical analyses were performed using an electron microprobe. Average delta18O and delta13C values from the Bloom Member are -4.5% +/- 1.6% (1 sigma) and 2.1% +/- 1.1%, respectively. Maximum delta13C values are about 1% higher for the Desmoinesian and Missourian than the Morrowan and Atokan, similar to results from the Yukon Territory. delta18O and delta13C values are lowest for crystalline mosaic limestones and siltstones, moderate for packstones, wackestones, and mudstones, and highest for boundstones and grainstones. The delta13C profile from Gallagher Peak consists of high frequency 1% oscillations with several larger excursions. No large delta13C increase at the base of the section suggests the Mid-Carboniferous boundary is in the underlying Bluebird Mountain formation. delta13C of Gallagher Peak and Arrow Canyon, NV, correlate well from 318 to 310 Ma, but correlation becomes more difficult around 310 Ma. This may result from increased restriction of the Snaky Canyon platform beginning in the Desmoinesian. Most of the short term (<1 Ma) isotopic excursions are the result of diagenesis. Two of the largest negative excursions at Gallagher Peak correlate with two large negative excursions at Big Hatchet Peak, NM, possibly due to sea level lowstands of the Desmoinesian. Phylloid algal mounds at Gallagher Peak are associated with positive excursions because of original aragonite composition and increased open marine influence. Positive excursions related to other facies characteristics also result from increased marine influence. The delta13C curve for the upper half of Gallagher Peak contains three repeated cycles of increasing delta13C over 1-1.5 Ma, which are possibly related to long-term sea level fluctuations. Given the complexity of each local environment, without detailed biostratigraphy, detailed rock descriptions, and analysis of the various rock components, delta13C stratigraphy of whole rocks can be misinterpreted.

No description available.

Thesis (Ph. D.)--California Institute of Technology, 1943. / No collective t.p.; titles transcribed from individual title pages. Includes bibliographical references.