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Erosion And Sedimentation In Lake Ashtabula, Southeastern North Dakota, Darryll T. Pederson

Theses and Dissertations

Erosion along the shore of Lake Ashtabula and nearshore and offshore sedimentation were studied from May 1969 to December 1970. The lake, located in the southeastern part of North Dakota, was formed when the Baldhill Dam stopped the flow of the Sheyenne River in 1950. Maximum depth of the lake is 45 feet in the inundated river channel immediately above the dam. The lake is 27 miles long and ranges in width from 1/3 to 1/2 mile.

Shoreline erosion, measured at stations located at 100-foot intervals around the margins of the lake, was found to be a major source of …

Geology Of Mclean County, North Dakota, John P. Bluemle

Theses and Dissertations

McLean County, in west-central North Dakota on the east side of the Williston Basin, is covered by 8,500 to 13,000 feet of Paleozoic, Mesozoic, and Cenozoic rocks, which dip to the west at low angles. The Tertiary Tongue River and Sentinel Butte Formations are widely exposed in McLean County, and the Tertiary Cannonball Formation is exposed in a few places. Glacial drift, assigned to a new formation, the Coleharbor Formation, occurs throughout the county and reaches a maximum thickness of at least 400 feet in certain preglacial valleys.

The eastern part of McLean County, part of the Missouri Coteau, is …

Quantitative Geomorphology And Hydrology Of The Cass River Basin, New Zealand, Frank J. Schulte

Theses and Dissertations

The Cass River drainage basin is in the Southern Alps in the central part of the South Island of New Zealand. The Alps are composed of complexly folded greywacke which is still actively rising. The basin has been modified by several glacial advances during Pleistocene time.

The Cass basin has a temperate climate characterized by a steep precipitation gradient. Its vegetation includes plants of the forest grassland, shrubland, swamp, rock, and river-bed associations.

The Cass basin may be divided into four geomorphic areas: bedrock areas, high-angle fans, moderate-angle fans, and a low-angle fan. The bedrock areas consist of fractured greywacke; …

Gastropoda Of The Fox Hills Formation (Maestrichtian) Of North Dakota, J. Mark Erickson

Theses and Dissertations

The Fox Hills Formation (Maestrichtian, Upper Cretaceous) in North Dakota contains a gastropod fauna of thirty-seven species. Five species, loganensis n. sp., Piestochilus feldmanni n. sp., Hercorhyncus (Hercorhyncus) hollandi n. sp., cvancarai n. sp., and Cancellaria siouxensis n. sp. , and genus, Dakotia, are newly described. Twenty-four genera in eighteen families representing four orders and two subclasses of Gastropoda are present. Eleven species in a like number of genera are newly reported from the Fox Hills For mation. Goniocylichna bisculnturata and rectilabrum occur in common with the gastropod fauna of the Ripley Formation of the Mississippi Embayment, which has the …

Concretions And Nodules In The Hell Creek Formation, Southwestern North Dakota, Gerald H. Groenwold

Theses and Dissertations

The Hell Creek Formation (Upper Cretaceous) in southwestern North Dakota consists of lagoonal and floodplain deposits and contains abundant concretions and nodules. Representative specimens of the concretions and nodules and their corresponding enclosing sediments were analyzed by thin section and by quantitative and qualitative x-ray diffraction methods.

Fourteen types of concretions and three types of nodules, classified according to shape and composition, have thus been defined. Concretionary types include calcareous sandstone lenses, “logs”, and irregular masses; sideritic sandstone lenses and irregular masses; calcareous and sideritic lignitic sandstone lenses; bone-cored rounded masses; coprolite-cored masses; jarosite bodies; pyrite spheres; baritic sandstone lenses; …

Groundwater Flow, Hydrochemistry, And Uranium Deposition In The Powder River Basin, Wyoming, J. Ladd Hagmaier

Theses and Dissertations

The relation between regional groundwater flow, hydrochemistry, and uranium distribution in the Powder River Basin indicates that uranium was deposited during the Tertiary Period in groundwater recharge areas where the groundwater changed from a sulfate-bicarbonate water to a bicarbonate-rich water.

The regional recharge and discharge areas of present-day groundwater-flow systems have about the same location as the recharge and discharge areas of the Tertiary groundwater-flow systems. The present-day groundwater is recharged in the eastern, western, and especially in the southern margins of the basin and is discharged in the valley of the Powder River, especially in the north. Flow nets …

The Petroleum Geology Of The Midale Subinterval In North Central North Dakota, Kent A. Johnson

Theses and Dissertations

The Mississippian Midale subinterval is the basal unit of the Ratcliffe interval of the Madison Group. The Midale subinterval, an important petroleum producing unit in North Dakota, is a dolomitized limestone which is approximately 40 feet thick. A detailed study of 17 oil fields in north central North Dakota was conducted to determine the petroleum geology of the Midale subinterval. The study was done with the use of 563 mechanical well logs and core samples from 10 wells.

The anhydrite and dolomite units of the Rival subinterval, which underlie the Midale, and the Ratcliffe interval, which over lies the Midale, …

Origin And Distribution Of Selenium In The Upper Cretaceous Niobrara And Pierre Formations, Northeastern North Dakota, Robert M. Novak

Theses and Dissertations

High concentrations of selenium, often as much as 28 ppm, have been found in the bentonitic zones near the contact of the Niobrara and Pierre Formations of Cretaceous age in northeastern North Dakota. A 64-foot section in the Pembina Hills area reveals that the highest selenium content occurs in shale and marlstone beds adjacent to the bentonite beds which, themselves, contain comparatively little selenium. Higher concentrations of selenium were found in the brown shale than in the black, with a small variation in color making a big difference in selenium content.

The selenium content of the shale and marlstone drops …