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Mineralogy, Dexter Perkins Oct 2020

Mineralogy, Dexter Perkins

Open Educational Resources

This is a beta version of an open access textbook on Mineralogy, current as of October 2020. For the most recently updated live version please see: https://opengeology.org/Mineralogy/


Llithostratigraphic Investigation And Components Of A Complete Petroleum System Within An Upper Devonian Carbonate-Evaporite Sequence : The Birdbear Formation, Williston Basin, North Dakota, Benjamin L. Engleman Jan 2015

Llithostratigraphic Investigation And Components Of A Complete Petroleum System Within An Upper Devonian Carbonate-Evaporite Sequence : The Birdbear Formation, Williston Basin, North Dakota, Benjamin L. Engleman

Theses and Dissertations

The Birdbear Formation of the Williston Basin of southwestern North Dakota represents one carbonate-evaporite sequence of the Late Devonian. The formation was deposited during regression on a broad, shallow epeiric shelf and is composed principally of dolomite, limestone and anhydrite. The Birdbear Formation is conformable with the Duperow Formation below and the Three Forks Formation above. The designations of 17 lithofacies form the context for describing hydrocarbon generation, migration and accumulation. Rock-Eval 6 and total organic carbon of 42 samples were used to identify the quality of source rocks present in the formation. Good and excellent source rocks were identified …


Lithostratigraphic Investigation Of A Late Devonian Carbonate-Evaporite Sequence; The Duperow Formation, Williston Basin, North Dakota, Zachary P. Alcorn Jan 2014

Lithostratigraphic Investigation Of A Late Devonian Carbonate-Evaporite Sequence; The Duperow Formation, Williston Basin, North Dakota, Zachary P. Alcorn

Theses and Dissertations

The Duperow Formation of northwestern North Dakota is a cyclical carbonate evaporite unit deposited on a shallow marine shelf during the early part of the Late Devonian (Frasnian). The formation forms the lower part of the Jefferson Group and lithostratigraphic review permits three informal members to be recognized: lower, middle, and upper. Petrographic, lithologic, and well log examination of drill cores and thin sections allows the identification of seven lithofacies within the three members. Lithofacies include; bioclastic wackestone/packstone (LF1), stromatoporoid boundstone/floatstone (LF2), Amphipora boundstone/floatstone (LF3), peloidal wackestone (LF4), dolomitic mudstone (LF5), microbially laminated dolowackestone (LF6), and anhydrite (Lf7). Lithofacies are …


Regional Stratigraphy Of The Newcastle Formation (Lower Cretaceous) In Eastern Montana And Western North Dakota, Adam J. Ulishney Jan 2005

Regional Stratigraphy Of The Newcastle Formation (Lower Cretaceous) In Eastern Montana And Western North Dakota, Adam J. Ulishney

Theses and Dissertations

The Newcastle Formation (Lower Cretaceous) consists of sandstone with interbedded shale, siltstone, and mudstone facies. This work shows that the regional stratigraphy of the unit is detailed enough for the interpretation of its depositional history and environments in eastern Montana. This work also illustrates the possible lowstand position of the Western Interior Seaway along with probable source areas providing sediments into the study area.

A total of 3446 geophysical wireline logs were used to determine formation tops of the Greenhorn, Mowry, Newcastle, Skull Creek, and Inyan Kara Formations. The log character of the Newcastle Formation was also described for all …


Discontinuities In The Icebox Formation (Ordovician), Williston Basin, North Dakota And Montana, Aaron J. Ulishney Jan 2004

Discontinuities In The Icebox Formation (Ordovician), Williston Basin, North Dakota And Montana, Aaron J. Ulishney

Theses and Dissertations

The Ordovician Winnipeg Group is composed of three formations; in ascending order, the Black Island Formation, the Icebox Formation, and the Roughlock Formation. The Icebox Formation is largely composed of shale. This work shows that discontinuities and coarser facies exist within the Icebox Formation and that they are traceable throughout the subsurface of North Dakota and eastern Montana. This work also illustrates possible sea-level changes during the deposition of the Icebox Formation along with probable source areas providing detrital sediments into the study area.

Gamma-ray wireline logs were used to distinguish the formations of the Winnipeg Group from each other, …


Fracture-Enhanced Porosity And Permeability Trends In The Bakken Formation, Williston Basin, Western North Dakota, Wayne B. Freisatz Jan 1991

Fracture-Enhanced Porosity And Permeability Trends In The Bakken Formation, Williston Basin, Western North Dakota, Wayne B. Freisatz

Theses and Dissertations

Fractures play a critical role in oil production from the Bakken Formation (Devonian and Mississippian) in the North Dakota portion of the Williston Basin. The Bakken Formation in the study area is known for its low matrix porosity and permeability, high organic content, thermal maturity, and relative lateral homogeneity. Core analysis has shown the effective porosity and permeability development within the Bakken Formation to be primarily related to fracturing.

In theory, lineaments mapped on the surface reflect the geometry of basement blocks and the zones of fracturing propagated upward from them. Fracturing in the Williston Basin is thought to have …


Tectonic History Of Billings And Southern Mckenzie Counties, Southwestern North Dakota, John J. Crashell Jan 1991

Tectonic History Of Billings And Southern Mckenzie Counties, Southwestern North Dakota, John J. Crashell

Theses and Dissertations

Billings and southern McKenzie Counties contain about 40 active oil and gas fields. In the same area, two major structural highs and several minor ones can be recognized. The first of these, the Billings anticline, extends approximately 60 km (18 mi.) along a north-south line in central Billings County, and is composed of two parallel folds. A second major structure, here termed the Rough Rider anticline, lies west of the Billings anticline, and also extends about 60 km (18 mi.) along a north-south line from north-central Billings County into southern McKenzie County. Both of these structures are fault-bounded on their …


Depositional Environments And Diagenesis Of The Lower Duperow Formation (Devonian), Billings Anticline, North Dakota, Randolph B. Burke Jan 1989

Depositional Environments And Diagenesis Of The Lower Duperow Formation (Devonian), Billings Anticline, North Dakota, Randolph B. Burke

Theses and Dissertations

The Duperow Formation is an Upper Devonian (Frasnian) subsurface unit in the Williston Basin in the north-central United States and south-central Canada. Despite its economic importance for hydrocarbons, no detailed accounts have been published on the Duperow Formation that integrate depositional environments, lithology, diagenesis, and pore studies on either a regional or local scale. It was the purpose of this study to construct a model of the depositional environments and diagenesis of the lower Duperow Formation in the Billings Anticline of west-central North Dakota, based on detailed analysis of 17 cores (225 m, 739 ft) and associated wireline logs and …


Sedimentary Depositional Cyclicity, Mission Canyon And Charles Formations (Mississippian), Williston Basin, North Dakota, Jean L. Hoff Jan 1989

Sedimentary Depositional Cyclicity, Mission Canyon And Charles Formations (Mississippian), Williston Basin, North Dakota, Jean L. Hoff

Theses and Dissertations

Workers within the Williston Basin have repeatedly reported the presence of sedimentary cyclicity within the carbonate and evaporite succession of the Mississippian Madison Group. Descriptions of cyclicity are diverse and commonly conflict. Previous work has been exclusively qualitative. This study used a group of statistical techniques in a method designed specifically for the objective identification and evaluation of cyclicity in the lithofacies sequence of the Mission Canyon and lower Charles Formations in North Dakota.

Twelve cores were sampled at every visually distinguishable lithologic unit. Forty-six lithologic components were counted in each sample on a presence-absence basis. The phi association coefficient …


Stratigraphy And Depositional History Of The Deadwood Formation (Upper Cambrian And Lower Ordovician), Williston Basin, North Dakota, Douglas B. Anderson Jan 1988

Stratigraphy And Depositional History Of The Deadwood Formation (Upper Cambrian And Lower Ordovician), Williston Basin, North Dakota, Douglas B. Anderson

Theses and Dissertations

Based on gamma-ray characteristics, the Deadwood Formation is divided into six informal, attribute-defined units, members A through F. Members A and Bare Late Cambrian in age; members C through Fare Early Ordovician in age. The type section of the Deadwood, in the northern Black Hills, is dominated by Upper Cambrian strata. Much thicker Lower Ordovician rocks occur in the deeper portion of the Williston Basin.

The Deadwood comprises the Sauk sequence and represents the initial Paleozoic transgression or the seas on the North American craton. Eight smaller-scale transgressive-regressive events occurred on the craton during the Late Cambrian and the Early …


Macropaleontology Of The Gunn Member, Stony Mountain Formation (Upper Ordovician), Manitoba And North Dakota, Frederick K. Lobdell Jan 1988

Macropaleontology Of The Gunn Member, Stony Mountain Formation (Upper Ordovician), Manitoba And North Dakota, Frederick K. Lobdell

Theses and Dissertations

The Gunn Member of the Stony Mountain Formation has long been known to contain an abundant and diverse fauna. This study was undertaken to identify and describe the macrofauna of the Gunn Member in the subsurface of North Dakota, previously neglected.

As a necessary first step, collections of fossils from outcrop were examined and identified. With the outcrop fauna serving as a reference collection, twenty cores from the North Dakota subsurface were examined, described, and their fossils sampled. Fossil and sediment samples were washed and sieved and the residues were picked for microscopic representatives of phyla usually considered to be …


Sedimentology And Stratigraphy Of Glacial Lake Souris, North Dakota: Effects Of A Glacial-Lake Outburst, Mark L. Lord Jan 1988

Sedimentology And Stratigraphy Of Glacial Lake Souris, North Dakota: Effects Of A Glacial-Lake Outburst, Mark L. Lord

Theses and Dissertations

Glacial-lake outbursts commonly occurred along the southern margin of the Laurentide Ice Sheet as ice-marginal lakes suddenly drained. These outbursts released huge volumes of water with tremendous erosive potential, forming large trench-shape channels. Although glacial-lake spillways have been studied in detail, the effects of outbursts on downstream lakes have not. The purpose of this study was to demonstrate the effects of the Glacial Lake Regina outburst on the lake that received the flows, Glacial Lake Souris.

Glacial Lake Souris, located in what is now North Dakota, was inundated by about 74 km3 of water carrying 25 km3 of sediment from …


Depositional Environments And Diagenesis, Winnipegosis Formation (Middle Devonian), Williston Basin, North Dakota, Nancy A. Perrin Jan 1987

Depositional Environments And Diagenesis, Winnipegosis Formation (Middle Devonian), Williston Basin, North Dakota, Nancy A. Perrin

Theses and Dissertations

In the Williston Basin, the Winnipegosis Formation is the major carbonate unit of the initial transgressive-regressive pulse of the Kaskaskia sequence. Twenty-two lithofacies were identified by well-log, core, and thin-section studies of Winnipegosis rocks; these belong to seven environments of deposition which include deep basin, deep shelf, shallow shelf, reef, lagoon, tidal flat, and evaporite basin. The deposition of the Winnipegosis and Prairie Formations were inter-related and occurred during six episodes. Following a brief hiatus separating the underlying Ashern Formation from the Winnipegosis, a clear, quiet, shallow-marine environment became established in the North Dakota portion of the Elk Point Basin. …


Stratigraphy And Depositional Environments Of The Three Forks Formation (Upper Devonian), Williston Basin, North Dakota, Gayle M. Dumonceaux Jan 1984

Stratigraphy And Depositional Environments Of The Three Forks Formation (Upper Devonian), Williston Basin, North Dakota, Gayle M. Dumonceaux

Theses and Dissertations

The Three Forks Formation (Upper Devonian) is present in the subsurface in the western two-thirds of North Dakota and is generally conformable with the underlying Birdbear Formation and the overlying Bakken Formation.

The Three Forks attains a maximum thickness of 265 feet (81 meters) in the central basin, east and south of the Nesson Anticline, and thins to an erosional edge in eastern North Dakota. The Three Forks is composed of micrite and dolomicrite, which may be fcssiliferous and argillaceous. From the study of core samples and detailed petrographic analysis of thin sections, five lithofacies were recognized and their extent …


Archean Metamorphism In Northwestern Ontario And Southeastern Manitoba, Kevin R. Henke Jan 1984

Archean Metamorphism In Northwestern Ontario And Southeastern Manitoba, Kevin R. Henke

Theses and Dissertations

Four areas are considered in this study. In Ontario, north-south traverses were made along Highway 599 between Savant Lake and Central Patricia, along the Vermilion River road (40 kilometers northeast of Sioux Lookout) and along Highway 105 between Vermilion Bay and Ear Falls (Fig. 3). The fourth area is centered at Bird River, northeast of Lac du Bonnet, Manitoba. The study areas are located in the Uchi, English River and Wabigoon Subprovinces.

The traverse along Highway 599 between Savant Lake and Central Patricia crosses the three subprovinces (Fig. 3). Pelites in the eastern Lake St. Joseph area (Uchi Sub province) …


Depositional Environments And History Of The Winnipeg Group (Ordovician), Williston Basin, North Dakota, Stephen C. Thompson Jan 1984

Depositional Environments And History Of The Winnipeg Group (Ordovician), Williston Basin, North Dakota, Stephen C. Thompson

Theses and Dissertations

The Winnipeg Group (Ordovician) in the Williston Basin, North Dakota, contains three formations. They are, in ascending order, the Black Island Formation, herein informally divided into lower and upper members, the Icebox Formation, and the Roughlock Formation. Strata of the Winnipeg Group (maximum thickness 400 ft., 122 m) represent the initial deposits of a Middle Ordovician craton-wide transgression. Throughout most of North Dakota, the Winnipeg is unconformably underlain by the Deadwood Formation (Upper Cambrian-Lower Ordovician) and conformably overlain by the Red River Formation (Upper Ordovician).

The strata of the lower member of the Black Island Formation consist of a red-bed …


Depositional Cycles And Coral Distribution, Mission Canyon And Charles Formations, Madison Group (Mississippian), Williston Basin, North Dakota, Douglas L. Waters Jan 1984

Depositional Cycles And Coral Distribution, Mission Canyon And Charles Formations, Madison Group (Mississippian), Williston Basin, North Dakota, Douglas L. Waters

Theses and Dissertations

The distribution of corals, other fossils, and rock types of the Madison Group in the Williston Basin were studied in 29 cores (involving over 6,200 feet of core) from the Bottineau, Tilston, Frobisher-Alida, and Ratcliffe intervals in the western half of North Dakota. Occurrence of rock types, corals, and other fossils (brachiopods, bryozoans, red algae, and gastropods) of the Mission Canyon and lower Charles Formations were plotted in three cross-sections against the informal marker-defined intervals (Tilston, Frobisher-Alida, and Ratcliffe), as identified from well logs. Distribution and abundance of corals in nine of the more extensive cores were related to interpreted …


Stratigraphy Of The Inyan Kara Formation (Lower Cretaceous) In The Vicinity Of The Nesson Anticline, Northwestern North Dakota, Brad L. Wartman Jan 1983

Stratigraphy Of The Inyan Kara Formation (Lower Cretaceous) In The Vicinity Of The Nesson Anticline, Northwestern North Dakota, Brad L. Wartman

Theses and Dissertations

The Lower Cretaceous Inyan Kara Formation, at the base of the Dakota Group, consists of sandstone, siltstone, shale, and coal. The stratigraphy of the Inyan Kara and facies relationships within the formation and with the underlying Swift and overlying Skull Creek Formations in the vicinity of the Nesson Anticline, northwestern North Dakota, were evaluated using 11 cross-sections, 163 borehole geophysical logs, and 1 well core.

The Inyan Kara can be differentiated on well logs into three members. The basal member, "A", consists of sandstone, siltstone, shale, and coal. It is about 200 feet (60 m) to 400 feet (122 m) …


Thermometry And Barometry Of Precambrian Orthogneisses And Related Rocks From The Minnesota River Valley, Southwestern Minnesota, Paula J. Leier May 1982

Thermometry And Barometry Of Precambrian Orthogneisses And Related Rocks From The Minnesota River Valley, Southwestern Minnesota, Paula J. Leier

Undergraduate Theses and Senior Projects

Granulite facies metamorphism is reported to have occurred in the Granite Falls-Montivideo area of the Minnesota River Valley and a broader view of the valley is taken to determine the extent of granulite facies metamorphism. Pressures and temperatures of metamorphism were determined using two geothermometers and one geobarometer. Based upon two-feldspar and garnet-biotite thermometers, temperature of metamorphism is approximated at 600 °c. Metamorphic pressures based on the reaction cordierite= garnet+ quartz + sillimanite were probably between 4 and 6 Kbars. Based on barometry and thermometry, it is suggested the Algoman o rogeny (2600 m.y. ago) was at least upper amphibolite …


Carbonate Bodies Within The Basal Swift Formation (Jurassic) Of Northwestern North Dakota, Tina M. Langtry Jan 1982

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 …


Paleocene Coal-Bearing Sediments Of The Williston Basin, North Dakota : An Interaction Between Fluvial Systems And An Intracratonic Basin, Laramie M. Winczewski Jan 1982

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, …


Stratigraphy And Sedimentology Of The Sentinel Butte Formation (Paleocene) Near Lost Bridge, Dunn County, West-Central North Dakota, Bradley D. Nesemeier Jan 1981

Stratigraphy And Sedimentology Of The Sentinel Butte Formation (Paleocene) Near Lost Bridge, Dunn County, West-Central North Dakota, Bradley D. Nesemeier

Theses and Dissertations

The Sentinel Butte Formation (Paleocene) near Lost Bridge, Dunn County, west-central North Dakota, is 190 meters thick, and is charac terized by four main lithologies: sand, silt, clay, and lignite. The study interval is ISO meters thick, and lies between the basal sand of the formation and the Bullion Butte lignite bed, neither of which are exposed in the immediate study area. Sand, gray to yellow, makes up about 3S% of the interval studied. It occurs in tabular beds 2-18 meters thick. It is fine to very-fine, angular, and composed largely of quartz, feldspar, rock fragments, with minor amounts of …


Stratigraphy And Depositional Environments Of The Wilcox Group (Paleocene) At The Oxbow Mine Site, Northwestern Louisiana, Richard E. Halle Jan 1981

Stratigraphy And Depositional Environments Of The Wilcox Group (Paleocene) At The Oxbow Mine Site, Northwestern Louisiana, Richard E. Halle

Theses and Dissertations

The stratigraphy, structure, and depositional environments of the Naborton, Do let Hills, and part of the Cow Bayou Formations (Wilcox Group, Paleocene) at the Oxbow Mine site, Red River, De Soto, and Natchitoches Parishes,. Louisiana, were evaluated from a study of four continuous cores and 466 geophysical logs.

Overlying 40 feet {12 m) of silty Porters Creek shale is the Naborton Formation composed of 130-195 feet (40-59 m) of sand, silt, clay, and lignite. There are three lignites in this formation and their average total thickness is 13.5 feet (4. l m), or about 10% of the formation thickness. The …


Late Pleistocene And Holocene Geology Of The Moe Site, New Town, North Dakota, Richard W. Kornbrath Jan 1975

Late Pleistocene And Holocene Geology Of The Moe Site, New Town, North Dakota, Richard W. Kornbrath

Theses and Dissertations

Eight stratigraphic units of Late Cenoioic age are present around the Moe Archeological Site near New Town, North Dakota. Unit Zero is a layer of glacial sediment consisting of grayish brown pebbly clay loam. Unit One consists of fluvial and beach sand and gravel. Unit Two consists of light yellowish brown, offshore lake silt that was deposited into a glacial lake in Late Wisconsinan time. Unit Three is a layer of glacial sediment consisting of grayish brown pebbly clay loam (Late Wisconsinan). Unit Four consists of fluvial sand and gravel (Late Wisconsinan}. Unit Five is a layer of slough sediment …


Glacial Stratigraphy Of Northeastern North Dakota, Howard Hobbs Jan 1975

Glacial Stratigraphy Of Northeastern North Dakota, Howard Hobbs

Theses and Dissertations

Seven lithostratigraphic units (formations} composed dominantly of glacial sediment have been recognized in northeastern North Dakota. Three formations, the Falconer Formation (Harris and others, 1974}, the Dahlen, and Gardar Formations (Salomon, 1975). Have been previously recognized. Four formations, the Hansboro, Vang, Tiber and Cando Formations are newly recognized. Uncorrelated units of glacial sediment are described but not named. The formations are differentiated and correlated primarily by the proportion of crystalline (igneous and metamorphic rock fragments), carbonate, and shale grains in the coarse sand fraction (1 to 2 mm) of the glacial sediment. The proportion of shale grains was. Found to …


Petrology And Geochemistry Of The Killdeer Carbonates, John J. Delimata Jan 1975

Petrology And Geochemistry Of The Killdeer Carbonates, John J. Delimata

Theses and Dissertations

The strata of the proposed Killdeer Formation (Stone, W. J., 1972) in the Killdeer Mountains of Dunn County, North Dakota is composed of a sequence of tuffaceous, calcareous, dolomitized and silicified flat lying sedimentary rocks of Tertiary age. It is the purpose of this report to describe and integrate the petrology and geochemistry of these sediments.

Fieldwork was conducted during the summer of 1972. Forty-three stratigraphic sections were measured and representative samples of each were collected for further analysis. Seven section were selected as representative of the area, and samples from these were studied in thin section with the petrographic …


Pleistocene Geology Of The Grand Forks-Bemidji Area, Northwestern Minnesota, Kenneth L. Harris Jan 1975

Pleistocene Geology Of The Grand Forks-Bemidji Area, Northwestern Minnesota, Kenneth L. Harris

Theses and Dissertations

This is a report of a reconnaissance study of the Quaternary geology of an area in northwestern Minnesota. Surface geology was studied in an area extending from Grand Forks, North Dakota, in the northwest to Bemidji, Minnesota, in the southeast, an area of 10 723 square kilometres (4140 square miles). Near-surface stratigraphy was studied in the area of surface study and an adjacent area of equal size to the south.

Surface materials mapped range in age from Pleistocene to Holocene and include glacial, glaciofluvial, lacustrine, bog, eolian, and alluvial sediments.

Sixteen power-auger test holes, two measured sections along the Red …


A Mechanical Well Log Study Of The Popular Interval Of The Mississippian Madison Formation In North Dakota, C. W. Cook Jan 1974

A Mechanical Well Log Study Of The Popular Interval Of The Mississippian Madison Formation In North Dakota, C. W. Cook

Theses and Dissertations

The Poplar interval of interbedded evaporites and carbonates forms the uppermost part of the Mississippian Madison Forr.1ation in western North Dakota. A detailed mechanical well log study of the Poplar interval in North Dakota was conducted to interpret the Poplar's regional geology and to attempt to locate areas with potential for petroleum production. Limestone, dolomite, anhydrite and salt were differentiated using mechanical well logs.

The complex facies of the Madison are subdivided into para-time rock units (the Poplar interval is one) on the basis of extensive thin anhydrite beds which are considered time-parallel.

The base of the Poplar interval is …


Heavy Minerals Of Glacial Sediments In The Area Of Red Lake Falls, Minnesota, Howard Hobbs Jan 1973

Heavy Minerals Of Glacial Sediments In The Area Of Red Lake Falls, Minnesota, Howard Hobbs

Theses and Dissertations

Pleistocene lithostratigraphic units containing glacial sediments in the Red Lake Falls, Minnesota, area and adjacent areas were studied to determine their heavy-mineral assemolages. Seventy-two samples of fine sand were studied by optical grain-count methods and 77 samples of fine sand were studied by x-ray diffraction methods. Most formations contain a hornblende-garnet-pyroxene-epidote assemblage; the Gervais Formation contains a pyroxene-hornblende assemblage. The mean proportion of the constituent minerals is different in each formation; however, there is overlap in the ranges of heavy mineral proportions among the formations. The Red Lake Falls Formation can be subdivided on the basis of garnet abundance.


Quaternary Geology Of Sargent County, North Dakota, Dennis N. Neilsen Jan 1973

Quaternary Geology Of Sargent County, North Dakota, Dennis N. Neilsen

Theses and Dissertations

Sargent County, in southeastern North Dakota, was glaciated during the Pleistocene Epoch. Objectives of a study of Sargent County were to (1) describe the surface sediment and interpret its origin, (2) correlate, where possible, this sediment with that of adjacent areas, and (3) recon struct the general geologic history of the county for the Quaternary Period.

A geologic map of the county was prepared using field data, topo graphic maps, aerial stereopairs, and soil maps. A map showing surface sediment origin was subsequently made using the available field and laboratory information.

Most of Sargent County is typical rolling prairie underlain …