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Paleocene Coal-Bearing Sediments Of The Williston Basin, North Dakota : An Interaction Between Fluvial Systems And An Intracratonic Basin, Laramie M. Winczewski

Theses and Dissertations

Outcrop and test hole data for 225 sites in a 33,700-km² area of southwestern North Dakota were examined. Seven sedimentation intervals were identified for the Paleocene Bullion Creek and Sentinel Butte Formations. The intervals extend from the top of the Harmon coal (lower Bullion Creek) to the top of the Twin Buttes coal (upper Sentinel Butte). Each interval consists of medium and fine elastics underlying a persistent lignite coal, or some other lithology at the stratigraphic position of the coal. Clastics are finer-grained upwards within intervals and within both formations to the upper Sentinel Butte.

Sand-rich zones align northwest-southeast, …

Petrology, Geochemistry And Economic Geology Of Selected Gold Claims In Rocks Of The Wasekwan Lake Area, Lynn Lake District, Manitoba, Canada, Douglas Scott Kenaley

Theses and Dissertations

The purpose of this investigation was to map and study, both at regional and detailed scales, the units encountered within seven gold claims that were staked by Sherritt-Gordon Mines Limited of Lynn Lake, Manitoba. The claims are located in the wasekwan Lake area, approximately 12. 8 km southeast of Lynn Lake. Regional mapping was conducted at a scale of 1:12000 over a 6.4 km2 area and detailed mapping of potentially economic areas was conducted at a scale of 1:240. Whole-rock geochemistry, microprobe, optical and X-ray diffraction procedures were employed to describe and characterize the rocks. The Aphebian rock units of …

Carbonate Bodies Within The Basal Swift Formation (Jurassic) Of Northwestern North Dakota, Tina M. Langtry

Theses and Dissertations

The carbonate bodies of the basal Swift Formation (Upper Jurassic) occur as anomalous deflections on a relatively uniform mechanical well log section. The areal distribution, stratigraphic relationships, and genesis of the carbonate bodies were determined by using the gamma ray log, the spontaneous-potential log, the resistivity log suite, and megascopic and microscopic core analysis.

The carbonate bodies of the basal Swift Formation are coarsening upward sequences composed of predominantly sand-sized, recrystallized mollusk grains. These grains were transported by strong bottom cur rents across the irregular sea floor of the shallow epicontinental Jurassic sea, and were deposited under agitated water conditions …

Glacial Geology And Stratigraphy Of Southeastern Pierce And Southwestern Benson Counties, North Dakota, Arthur W. Schnacke Jr.

Theses and Dissertations

The study area includes 220 square miles in southeastern Pierce and southwestern Benson Counties, North Dakota (T. 152 N. through T. 154 N., R. 70 W. through R. 73 W.).

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Field mapping and subsequent analyses were attempted to differentiate the drifts of the Leeds and Souris lobes, to determine the sequence and duration of events during and subsequent to glaciation, and to aid in correlating the drifts. Landforms of the area include: ice marginal ridges, ground moraine, proglacial plains, abandoned river channels, and sand dunes.

In the laboratory, very coarse sand lithology percentages, till fabric, texture, and gross lithology …

Depositional Environments And Diagenesis Of The Ratcliffe Interval, Madison Group (Mississippian), Williston Basin, North Dakota, Diane M. Catt

Theses and Dissertations

The Ratcliffe interval in North Dakota is a log marker-defined unit in the Williston Basin. It is Mississippian in age and crosscuts the lower Charles and upper Mission Canyon Formations of the Madison Group. Study of cross-sections, well core, and thinsections show that the Ratcliffe is comprised of six major facies: 1) brachiopod-bryozoan-echinoderm wackestone/packstone, 2) peloid packstone/wackestone, 3) oolite-peloid packstone, 4) laminated mudstone, 5) quartz siltstone packstone, and 6) anhydrite-dolomite mudstone. These facies were deposited in a regressive setting.

The initial deposition consisted mainly of marine limestones. The environment gradually became more restricted and deposition of large amounts of anhydrite …

Analysis Of Petroleum Source Rocks Of The Bakken Formation (Devonian And Mississippian) In North Dakota, Rick L. Webster

Theses and Dissertations

The Bakken Formation of North Dakota consists of upper and lower, black, organic-rich shales separated by a calcareous siltstone middle member. The formation is a relatively thin unit (maximum thickness of 145 feet) with the lower shale .attaining a maximum thickness of 50 feet and the upper shale a maximum thickness of 23 feet. The shales are hard, siliceous, pyritic, fissile, and noncalcareous. They contain abundant conodonts and tasmanites and have planar laminations accented by pyrite. The upper and lower shales were apparently deposited in an offshore, marine, anoxic environment where anoxic conditions may have been caused by silling of …

Petrology And Alteration In The Core Of The Bear Lodge Tertiary Intrusive Complex, Bear Lodge Mountains, Crook County, Wyoming, Michael Wilkinson

Theses and Dissertations

The Bear Lodge complex is an elongate, dome-shape uplift about 8.5 km long by 4 km wide, 10 km northwest of Sundance, Wyoming. The study area is centered about Warren Peaks and includes approximately 23 km2. The igneous intrusive core of the complex is mostly alkali trachyte but latite is abundant in the southern portion of the complex. Phonolite, pseudoleucite trachyte porphyry, and carbonatite dikes cut across the core. Precambrian granitic rocks and lower Paleozoic sedi mentary rocks flank the intrusion and occur as xenoliths.

The latite is relatively unaltered and consists mostly of oligo clase, andesine, alkali feldspar, salite, …

Depositional Environments And Sandstone Diagenesis In The Tyler Formation (Pennsylvanian), Southwestern North Dakota, Stephen D. Sturm

Theses and Dissertations

The Tyler Formation, of Early Pennsylvanian age, in southwestern North Dakota may be divided into upper and lower units, reflecting both a change in lithology and depositional environments. The lower unit is dominated by varicolored, noncalcareous shales and mudstones, siltstones, thin coal beds, and medium-grained sandstones. The upper unit in the areas of the Square Butte to Fryburg fields may be divided into a lower subunit, dominated by dark gray to grayish-black, argillaceous limestones and calcareous shales, and an upper subunit dominated by grayish-red, anhydritic limestones, varicolored to reddish-brown, calcareous shales, and locally, thin anhydrite. In the area of the …

Depositional Environment And Diagenesis, Birdbear Formation (Upper Devonian) Williston Basin, North Dakota, Peter T. Loeffler

Theses and Dissertations

The Birdbear Formation is a subsurface unit that is present throughout North Dakota except where truncated by post-depositional erosion. An angular unconformity is present between the Birdbear and younger strata in areas where the Three Forks Formation does not overlie the Birdbear. An isopach map of the Birdbear, constructed from drill-hole log data, indicates that the formation generally thickens gradually from the erosional limit to a maximum of 119 feet north of the center of the Basin. A structure map o~ the top of the Birdbear shows a basin that reaches 9000 feet below sea level.

The Birdbear is predominantly …