Physical Sciences and Mathematics Commons^™

Geology And Petrology Of The Devils Tower, Missouri Buttes, And Barlow Canyon Area, Crook County, Wyoming, Don L. Halvorson

Theses and Dissertations

Field and laboratory investigations were employed to detmine the mode of emplacement and a petrogenetic model for three igneous localities in Crook County, Wyoming: the Devils Tower, the Missouri Buttes, and the Barlow Canyon area.

X-ray fluorescence, microprobe data, and optimal analyses iden tify the Missouri Buttes rock as foid-bearing alkali trachyte and anal cime phonolite and the Devils Tower and Barlow Canyon rocks as analcime phonolite.

Associated alloclastic breccia with a crystal-charged volcanic glass matrix, surrounding depressions representing collapse of igneous material back into the vent, striking similarity to known volcante necks, and the occurrence of other extrusive volcan1S11\ …

Kaolinitic Weathering Zone On Precambrian Basement Rocks, Red River Valley, Eastern North Dakota And Northwestern Minnesota, Lynne Irvine Kelley

Theses and Dissertations

A suite of 26 drill cores recovered from the Red River Valley Drilling Project has provided new information on the Precambrian basement of eastern North Dakota and northwestern Minnesota. Basement rocks in this area consist of intermediate to felsic coarse-grained massive or gneissic rocks, and intermediate to mafic metavolcanic and metasedimentary schists. The Precambrian rocks of the region are interpreted to be a buried extension of the Superior Province of the Canadian Shield, and are divided into terranes of granitic rock and mafic schist, on the basis of drill-hole samples, patterns seen in Superior Province rocks which crop out to …

Surface Geology For Land Use Planning, Minot, North Dakota Area, Garth S. Anderson

Theses and Dissertations

The Minot area includes about 330 square kilometres along both sides of the Souris River in north-central North Dakota. The area can be divided into the flat Souris River floodplain, the steeply sloping sides of the Souris and Des Lacs meltwater channels and larger tributaries, and the gently undulating uplands dissected by small streams. Surficial geologic units include Early Tertiary sand, silt, clay, and sandstone of the Bullion Creek Formation, Pleistocene glacial till, ice contact fluvial deposits, and other fluvial deposits of the Coleharbor Group, and Holocene fluvial and eolian deposits of the Oahe Formation.

Expansion of the Minot metropolitan …

Periglacial Landforms And Processes In The Southern Kenai Mountains, Alaska, Palmer K. Bailey

Theses and Dissertations

The distribution and characteristics of periglacial landforms in the southern Kenai Mountains, Alaska, were investigated during the summer of 1979. The principal area of study was a 1300-metre high mountain mass which stood as a nunatak during the last general glaciation. Periglacial features in the area include gelifluction lobes, nivation hollows, cryoplanation terraces, tors, a string bog, and various for111S of patterned ground such as sorted circles, sorted polygons, earth hummocks, sorted steps, sorted stripes, and small ice-wedge polygons.

Ground temperature measurements indicate that permafrost recently existed in the area but is no longer present. The sorted polygons, cryoplsnation terraces, …

Petrology Of The Cenozoic Igneous Rocks Of The Lytle Creek Area, Bear Lodge Mountains, Wyoming, Stanely F. White

Theses and Dissertations

The purpose of this study was to map and study the petrology of the Cenozoic igneous rocks that crop out in the Lytle Creek area located in the southwestern Bear Lodge Mountains of northeastern Wyoming. Petro graphic and chemical data is used to interpret the Cenozoic phonolite trachyte rock association.

Cenozoic igneous activity in the Lytle Creek area appears to have been a response to the Laramide orogeny 80-40 m.y. B.P. The majority of the rocks were emplaced as laccoliths and sills at the Pahasapa Formation-Minnelusa Formation contact or at the Spearfish Formation Sundance Formation contact. Porphyritic volcanic textures are …

Paleoenvironmental Analysis Of A Late Holocene Deposit : Stanton Site, West-Central North Dakota, David W. Fischer

Theses and Dissertations

The Stanton Site (W1/2NE1/4 sec. 16, T. 144 N., R. 85W.), eastern Mercer County, North Dakota, contains a late Holocene organic deposit in the cutbank of an ephemeral stream on the Missouri Plateau. Strati graphic units of the 104-cm section are, in ascending order: (l) gravel; (2) silty, organic, sandy clay; (3) organic silt; (4) silty, sandy, organic clay; (5) organic silt; (6) sandy, silt, organic clay; and (7) sand. A radiocarbon date of wood from the base of unit 2 indicates initiation of deposition at 325±_115 radiocarbon years B.P.

Abundant well-preserved fossils are present in the organic sediments of …

Postglacial Ostracod Distribution And Paleoecology, Devils Lake Basin, Northeastern North Dakota, James B. Van Alstine

Theses and Dissertations

Sediment cores were taken from Main Bay and Creel Bay of Devils Lake (in 1975 and 1976) and East Devils Lake (in 1978), within the Devils Lake basin, and from Red Willow Lake (in 1979), a control lake outside of the Devils Lake basin, northeastern North Dakota. The cores were sampled, for the recovery of the ostracods, at 10-cm intervals. Fifteen species of ostracods were present in the studied cores: 8 candonids, 1 cyclocyprid, 3 cyprids, and 3 limnocytherids. Two distinct faunas are recognized. The Devils Lake-East Devils Lake fauna consists of Candona lactea, C. rawsoni, Cyprinotus glaucus, Potamocypris smaragdina, …

Stratigraphy, Sedimentology, And Depositional Environments Of The Hell Creek Formation (Late Cretaceous) And Adjacent Strata, Glendive Area, Montana, Raymond D. Butler

Theses and Dissertations

The Colgate Member (Fox Hills Formation), Little Beaver Creek, Marmarth, Bacon Creek, Huff, and Pretty Butte Members (Hell Creek Formation), and lower Ludlow Formation in the Glendive area, Montana consist of sandstone, sandy siltstone, shale, and lignite. The Colgate is 24 m thick and consists of mostly sandstone, The Hell Creek Formation (Late Cretaceous) is 120 m thick, The basal member, the Little Beaver Creek, is up to 12 m thick and consists of about half sandstone and half shale. The Marmarth is 24 to 30 m thick and consists of mostly sandstone. The Bacon Creek is 36 m thick …

Distribution And Origin Of Elongate Sandstone Concretions, Bullion Creek And Slope Formations (Paleocene), Adams County, North Dakota, Michael W. Parsons

Theses and Dissertations

Rectilinear patterns in sandstone are visible on aerial photo graphs of Adams County, North Dakota. These patterns result from the differential erosion of elongate, calcareous, sandstone concretions that have formed in fluvial channel sand units.

The distribution and orientation of the elongate concretions were mapped from aerial photographs. The concretions have a strongly east-west orientation. Averages of paleocurrent measurements of the associated sand and sandstone are also easterly.

The elongate concretions occur slightly above and below the Rhame bed (a white marker zone at the top of the Slope Formation), in sand units at the base of the Bullion Creek …

Authigenic Kaolinite In The Bear Den Member (Paleocene) Of The Golden Valley Formation, In Southwestern North Dakota, Gordon H. Prichard

Theses and Dissertations

The Golden Valley Formation of North Dakota crops out in isolated remnants over a large area of southwestern North Dakota. The formation has two members, the lower Bear Den Member, which is characterized by kaolin and bright colors and the upper Camels Butte Member, which is characterized by micaceous sand and clay.

Two different theories, either in place weathering or detrital deposition, have developed as to the origin of the kaolinite in the lower member. Early workers suggest that the kaolinite of the member is detrital in origin for the following reasons:

1. No unconformity is present at the top …

Molluscan Paleontology Of The Pliocene Peace Valley "Beds" And Ridge Route "Formation" (Ridge Basin Group), Ridge Basin, Southern California, Daniel R. Young

Theses and Dissertations

The Ridge Basin, 90 km northwest of Los Angeles, California, lies within the San Gabriel, San Andreas, Liebre, and Clearwater fault zones. The basin is an elongated, wedge-shaped, intermontane, Miocene-Pliocene basin filled with about 12 000 m of marine, lacustrine, fluvial, and alluvial sediment. More than half of the thickness of the Ridge Route "formation" and about one fifth of the Peace Valley "beds" was examined for molluscs along the northeastern side of the basin and more than 600 m of section were measured.

The nonmarine molluscs of the Ridge Route "formation" and Peace Valley "beds" consist of ten species: …