Geology Commons^™

The Influence Of The Great Falls Tectonic Zone On The Thrust Sheet Geometry Of The Southern Sawtooth Range, Montana, Usa, Caroline M. Burberry, J. M. Palu

Department of Earth and Atmospheric Sciences: Faculty Publications

The reactivation potential of pre-existing deep-seated structures influences deformation structures produced in subsequent compression. This contribution investigates thrust geometries produced in surface thrust sheets of the Sawtooth Range, Montana, USA, deforming over a previously faulted sedimentary section. Surface thrust fault patterns were picked using existing maps and remote sensing. Thrust location and regional transport direction was also verified in the field. These observations were used to design a series of analogue models, involving deformation of a brittle cover sequence over a lower section with varying numbers of vertical faults. A final model tested the effect of decoupling the upper cover …

Integration And Delivery Of Interferometric Synthetic Aperture Radar [Insar] Data Into Stormwater Planning Within Karst Terranes, Brian Bruckno, Andrea Vaccari, Edward Hoppe, Scott Acton, Elizabeth Campbell

Department of Earth and Atmospheric Sciences: Faculty Publications

As part of two USDOT-funded studies focused on the development of satellite-based Interferometric Synthetic Aperture Radar (InSAR) technology, the researchers integrated InSAR-derived point cloud data into the transportation design process to optimize the location of a stormwater management system in a karst terrane. After initial validation, the InSAR data (over 1.67 million data points comprising various “scatterers”) were brought into a GIS dataframe and georeferenced to locations of known sinkholes. This dataset was then used to evaluate karst hazard within a 40x40km data frame located in the Valley and Ridge Province of Virginia. The group identified systematic kinematic differences in …

Post-Mississippian Tectonic Evolution Of The Nemaha Tectonic Zone And Midcontinent Rift System, Se Nebraska And N Kansas, Caroline M. Burberry, R. Matthew Joeckel, Jesse T. Korus

Department of Earth and Atmospheric Sciences: Faculty Publications

The geologic structures of the central Midcontinent of the USA are largely buried and known only from geophysical datasets, coupled with sparse well control and limited outcrop. Such unconstrained geophysical models preclude a deeper assessment of possible continental interior seismic hazards, which have the potential to cause appreciable damage. Within the study area in southeastern Nebraska and northeastern Kansas is an area of elevated seismic risk, with a spatial relationship to the Nemaha Tectonic Zone and the Midcontinent Rift System. Using sequential restorations of three published cross sections within Nebraska and Kansas this study demonstrates that the Nemaha Tectonic Zone …

The Effect Of Basement Fault Reactivation On The Triassic—Recent Geology Of Kurdistan, North Iraq, Caroline M. Burberry

Department of Earth and Atmospheric Sciences: Faculty Publications

The Zagros orogenic belt is underlain by a complex faulted Precambrian basement. Major fault trends originating in this basement have been invoked to explain large-scale structural changes along the strike of the orogen, e.g. the development of the Kirkuk Embayment (Kurdistan, Iraq) and the Lurestan Salient (Iran). However, within the Kirkuk Embayment, these structural trends have not previously been considered as an interacting group of faults which are periodically reactivated. This contribution first presents a revised basement fault map for the Kirkuk Embayment, created from interpreted gravity data, existing fault maps and remote sensing lineament analyses. This map is then …

4-D Evolution Of Anticlines And Implications For Hydrocarbon Exploration Within The Zagros Fold-Thrust Belt, Kurdistan Region, Iraq, Mjahid M. Zebari, Caroline M. Burberry

Department of Earth and Atmospheric Sciences: Faculty Publications

The Zagros Fold-Thrust Belt, extending from southern Iran, through northern Iraq and into Turkey, is characterized by elongate NW-trending anticlines that house large hydrocarbon accumulations. In recent years, the Kurdistan region of northern Iraq has become an area of interest for both structural studies and petroleum exploration-related investigation. Key questions to be answered concern the nature of the anticlines and whether the geometry of any associated thrusts can be predicted from surface geomorphology, as well the 4-D evolution of the area and along-strike continuity of the anticlines. To address these questions, this study combines field data, remote-sensing data concerning the …

Architecture, Heterogeneity, And Origin Of Late Miocene Fluvial Deposits Hosting The Most Important Aquifer In The Great Plains, Usa, R. Matthew Joeckel, Steve R. Wooden Jr., Jesse T. Korus, Jon Garbisch

Department of Earth and Atmospheric Sciences: Faculty Publications

The Ash Hollow Formation (AHF) of the Ogallala Group is an important sedimentary archive of the emergence of the Great Plains and it contains major groundwater resources. Stratal patterns of constituent alluvial lithofacies demonstrate that the AHF is much more heterogeneous than is commonly assumed. Very fine- to fine-grained sandstone dominate overall, chiefly lithofacies Sm (massive to locally stratified sandstone). Stacked, thin sheets of Sm with accretionary macroform surfaces are common, indicating that many sandstone architectural elements originated as compound-bar deposits in dominantly sand-bed streams. Channel forms are difficult to identify and steep cutbanks are absent. Multiple units of lithofacies …

Dune Formation On Late Holocene Sandy Bay Barriers Along Lake Michigan’S Door Peninsula: The Importance Of Increased Sediment Supply Following The Nipissing And Algoma High Lake-Level Phases, J. Elmo Rawling Iii, Paul R. Hanson

Department of Earth and Atmospheric Sciences: Faculty Publications

This study focuses on the geomorphology and geochronology of dunes formed on three sandy barrier systems at Clark, Europe and Kangaroo Lakes in Wisconsin’s Door Peninsula. The Lake Michigan shoreline in the peninsula contains abundant evidence for fluctuations in lake level with paleo-shoreline features that lie up to ~7 m above the present shoreline. Dunes are not very common along the Lake Michigan shoreline in Wisconsin, but the three bay barriers studied contain beach ridges that were buried by varying depths of eolian sand in the form of low relief sandsheets as well as parabolic and transverse dunes that have …

Coastal Geology And Recent Origins For Sand Point, Lake Superior, Timothy G. Fisher, David E. Krantz, Mario R. Castaneda, Walter L. Loope, Harry M. Jol, Ronald J. Goble, Melinda C. Higley, Samantha Dewald, Paul R. Hanson

Department of Earth and Atmospheric Sciences: Faculty Publications

Sand Point is a small cuspate foreland located along the southeastern shore of Lake Superior within Pictured Rocks National Lakeshore near Munising, Michigan. Park managers’ concerns for the integrity of historic buildings at the northern periphery of the point during the rising lake levels in the mid-1980s greatly elevated the priority of research into the geomorphic history and age of Sand Point. To pursue this priority, we recovered sediment cores from four ponds on Sand Point, assessed subsurface stratigraphy onshore and offshore using geophysical techniques, and interpreted the chronology of events using radiocarbon and luminescence dating. Sand Point formed at …

Reservoir Potential Of Sands Formed In Glaciomarine Environments: An Analog Study Based On Cenozoic Examples From Mcmurdo Sound, Antarctica, Christopher R. Fielding, Brian A. Blackstone, Tracy D. Frank, Zi Gui

Department of Earth and Atmospheric Sciences: Faculty Publications

This paper provides documentation of unexpectedly high-reservoir-quality glaciomarine sands found in the Cenozoic succession beneath McMurdo Sound, Antarctica, as an analogue study for evaluations of hydrocarbon prospectivity in basins elsewhere. The Oligocene to Lower Miocene succession of the Victoria Land Basin, an extant portion of the West Antarctic Rift System, comprises diamictites, mudrocks, and sandstones with minor conglomerates. These lithologies are arranged in repetitive stacking patterns (cycles), interpreted to record repeated advance and retreat of glaciers into and out of the basin, with attendant eustatic and isostatic effects. Phases of ice retreat within the cycles comprise an array of mudrocks, …

Rinded Iron-Oxide Concretions: Hallmarks Of Altered Siderite Masses Of Both Early And Late Diagenetic Origin, David Loope, Richard Kettler, Karrie A. Weber, Nathan L. Hinrichs, Derek T. Burgess

Department of Earth and Atmospheric Sciences: Faculty Publications

Iron-bearing concretions are valuable records of oxidation states of subsurface waters, but the first concretions to form can be altered drastically during later diagenetic events. Distinctive concretions composed of heavy rinds of iron oxide that surround iron-poor, mud-rich cores are common along bases of fluvial cross-bed sets of the Cretaceous Dakota Formation, Nebraska, USA. Concretion rinds thicken inward and cores contain 46 to 89% void space. Millimeter-scale spherosiderites are abundant in palaeosols that developed in floodplain facies. Evolution of rinded concretions began when intraformational clasts were eroded from sideritic soils, transported, abraded and deposited in river channels. Alteration of siderite …

Taxonomic Composition, Paleoecology And Biostratigraphy Of Late Cretaceous Diatoms From Devon Island, Nunavut, Canadian High Arctic, Jakub Witkowski, David M. Harwood, Karen Chin

Department of Earth and Atmospheric Sciences: Faculty Publications

Upper Cretaceous sediments of the Kanguk Formation exposed in Eidsbotn and Viks Fiord grabens on Devon Island, Nunavut, Canadian High Arctic, yielded 91 fossil marine diatom species and varieties (including indeterminate taxa), representing 41 genera. Excellent preservation of the assemblages was aided by shallow burial, protection in down­faulted linear grabens, and the presence of abundant volcanic material. Planktonic species and resting spores com­prise nearly 70% of the diatom assemblage, and provided abundant food resources for the Late Cretaceous Arctic eco­system. Deposition of the approximately 225 m-thick stratigraphic sequence was predominantly in a shallow marine neritic setting, with an upward progression …

A Study Of Fold Characteristics And Deformation Style Using The Evolution Of The Land Surface: Zagros Simply Folded Belt, Iran, Caroline M. Burberry, John W. Cosgrove, Jian-Guo Liu

Department of Earth and Atmospheric Sciences: Faculty Publications

Deformation styles within a fold-thrust belt can be understood in terms of the spatial organization and geometry of the fold structures. In young fold-thrust belts such as the Zagros, this geometry is reflected topographically by concordant landform morphology. Thus, the distribution of deformation structures can be characterized using satellite image analysis, digital elevation models, the drainage network and geomorphological indicators. The two distinct fold types considered in this study (fault-bend folds and detachment folds) both trending NW-SE, interact with streams flowing NE-SW from the High Zagros Mountains into the Persian Gulf. Multiple abandoned stream channels cross fault-bend folds related to …

Evolution Of The Cretaceous Calcareous Nanofossil Genus Eiffellithus And Its Biostratigraphic Significance, Jamie L. Shamrock, David K. Watkins

Department of Earth and Atmospheric Sciences: Faculty Publications

The calcareous nanofossil genus Eiffellithus is an important taxon of mid- to Upper Cretaceous marine sediments in biostratigraphy and paleoceanography. The definition of species within Eiffellithus have been both broadly interpreted and variably applied by nanofossil workers. This is particularly true for the Eiffellithus eximius plexus. While the taxonomy of mid-Cretaceous Eiffellithus species has recently been well-defined, the remaining 35 m.y. history of the genus has not been closely examined. Our investigation of Cenomanian to Maastrichtian sediments from the Western Interior Seaway, Gulf of Mexico, and Western Atlantic gives rise to six new species of Eiffellithus that can be reliably …

Geology Beneath The Primary Management Systems Evaluation Area (Msea) Site Southwest Of Shelton, Buffalo County, Nebraska, Robert F. Diffendal Jr., Frank A. Smith

Department of Earth and Atmospheric Sciences: Faculty Publications

In 1990, as part of a national presidential initiative on water quality, researchers from the University of Nebraska-Lincoln (UNL) Institute of Agriculture and Natural Resources (IANR) received a multi-year grant from the United States Department of Agriculture, Cooperative State Research Service, to study management of irrigated com and soybeans to minimize groundwater contamination. D.G. Watts, R.F. Spalding, and J.S. Schepers, of the IANR led a study at one of the Management Systems Evaluation Areas (MSEA). This area was made up of two sites, a primary site on a terrace of the Platte River near Shelton and a secondary site nearer …

Geologic Framework Of The Niobrara River Drainage Basin And Adjacent Areas In South Dakota Generally East Of The 100th Meridian West Longitude And West Of The Missouri River, Robert F. Diffendal Jr., Michael R. Voorhies

Department of Earth and Atmospheric Sciences: Faculty Publications

General geology and stratigraphy of the Niobrara River drainage basin in Nebraska and adjacent parts of South Dakota generally west of the Missouri River is reviewed. Of particular importance are the correlation of the Long Pine Formation of Pliocene age in Nebraska with the Herrick Gravels in South Dakota, the recognition of the members of the Ogallala Group named by Skinnner, Skinner and Gooris (1968) and by Skinner and Johnson (1984) in the basin, the acceptance of the relationships of the Miocene and older Tertiary units in the basin to those in the part of the study area in South …

Glacial Chronology Of The Ruby Mountains–East Humboldt Range, Nevada, William J. Wayne

Department of Earth and Atmospheric Sciences: Faculty Publications

The Ruby Mountains-East Humboldt Range, one of the interior mountain groups of the Basin and Range Province, lies about midway between the Wasatch Mountains and the Sierra Nevada. After Blackwelder’s description in his review of glaciation in the western mountains, Sharp mapped and named the deposits of the Lamoille and Angel Lake glaciations and correlated them with early and late Wisconsin deposits of the Great Lakes area. The refinement of relative dating (RD) methods, the availability of air photos and modem topographic maps, and new road cuts have aided the restudy of these alpine glacial deposits and the basis for …

Epeirogenic And Climatic Controls Of Early Pleistocene Fluvial Sediment Dispersal In Nebraska, K. O. Stanley, William J. Wayne

Department of Earth and Atmospheric Sciences: Faculty Publications

The change from Pliocene to Pleistocene fluvial sedimentation in Nebraska is denoted by gravel with relative enrichment of mechanically weak rock species and a two-fold increase in largest clast size. These changes in fluvial sediments suggest modification in degradational energy affecting detritus apparently related to deterioration of climate in the early Pleistocene. Cooler Pleistocene climates with increased moisture resulted in greater discharge and carrying capacity for streams headed in the Rocky Mountains and flowing across Nebraska. These streams carried granitic detritus eastward toward the continental glacier margin in easternmost Nebraska. There, streams flowing off ice sheets carrying sedimentary and metamorphic …

Native Indiana Iron Ores And 19th Century Ironworks, William J. Wayne

Department of Earth and Atmospheric Sciences: Faculty Publications

Introduction / 1

Phase one: Charcoal and native ores / 4

Northern Indiana ironworks and the postglacial bog ores / 4

Southern Indiana ironworks, Pennsylvanian and Mississippian ores / 10

Phase two: Block coals and Missouri ores / 15

Selected bibliography / 21

"The coming of iron manufacturers into the Indiana field should be encouraged. The reopening of ore deposits, the development of the coal fields, the building of furnaces within the state to smelt northern ores, the building of new railroads, and the extension of others, and the aggressive policy of existing roads to encourage industries along their lines, …

Report Of The Geologist, Erwin Hinckley Barbour

Department of Earth and Atmospheric Sciences: Faculty Publications

THE PROBLEM OF OUR SOILS AND SOIL MOISTURE.

The soil survey of the state, which was begun by the author in November of 1892, has progressed to the point where it might be considered finished. That is, one or more samples of soils have been taken from every distinct soil region in the state-in fact, most of the separate counties are represented, and mechanical analyses of many of these have already been made. However, in consideration of the size of our counties, the work will not be declared complete until each is represented in the state museum by soil prisms …