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Age And Paleoenvironmental Significance Of The Frazer Beach Member—A New Lithostratigraphic Unit Overlying The End-Permian Extinction Horizon In The Sydney Basin, Australia, Stephen Mcloughlin, Robert S. Nicoll, James L. Crowley, Vivi Vajda, Chris Mays, Christopher R. Fielding, Tracy D. Frank, Alexander Wheeler, Malcolm Bocking
Age And Paleoenvironmental Significance Of The Frazer Beach Member—A New Lithostratigraphic Unit Overlying The End-Permian Extinction Horizon In The Sydney Basin, Australia, Stephen Mcloughlin, Robert S. Nicoll, James L. Crowley, Vivi Vajda, Chris Mays, Christopher R. Fielding, Tracy D. Frank, Alexander Wheeler, Malcolm Bocking
Department of Earth and Atmospheric Sciences: Faculty Publications
The newly defined Frazer Beach Member of the Moon Island Beach Formation is identified widely across the Sydney Basin in both outcrop and exploration wells. This thin unit was deposited immediately after extinction of the Glossopteris flora (defining the terrestrial end- Permian extinction event). The unit rests conformably on the uppermost Permian coal seam in most places. A distinctive granule-microbreccia bed is locally represented at the base of the member. The unit otherwise consists of dark gray to black siltstone, shale, mudstone and, locally, thin lenses of fine-grained sandstone and tuff. The member represents the topmost unit of the Newcastle …
Plant Root Systems Preserved In The Permian Cedar Mesa Sandstone At Moki Dugway, Southeastern Utah, David Loope
Plant Root Systems Preserved In The Permian Cedar Mesa Sandstone At Moki Dugway, Southeastern Utah, David Loope
Department of Earth and Atmospheric Sciences: Faculty Publications
Rooted green plants represent the base of the food chain for most terrestrial ecosystems, but, compared to animal burrows, root systems are relatively rarely recognized in ancient sedimentary rocks. Plant roots that penetrate unconsolidated sand dunes, especially those containing not only quartz grains, but also abundant grains of calcite (CaCO3), are commonly replaced by fine crystals of calcite (Klappa, 1980). These structures (known by geologists as rhizoliths from the Greek for “root rock”) are one form of calcite cemented soil and sediment called caliche (Figure 1). Caliche crystallizes well above the water table and its calcite crystals are …
Cut, Fill, Repeat: Slot Canyons Of Dry Fork, Kane County, David Loope
Cut, Fill, Repeat: Slot Canyons Of Dry Fork, Kane County, David Loope
Department of Earth and Atmospheric Sciences: Faculty Publications
The slot canyons of southern Utah (figure 1) have become popular destinations for hikers, climbers, and photographers. For most of these canyons, the geology is simple: sediment carried by flowing water abrades a thick, homogeneous sandstone. As time passes, the rate of down-cutting is rapid compared to the rate of cliff retreat. End of story. The strange abundance and configuration of the slot canyons along Dry Fork Coyote (a tributary of Coyote Gulch and the Escalante River), however, have a convoluted geologic history that is climate-driven and involves canyon cutting, canyon filling, and more canyon cutting.
Plant Root Systems Preserved In The Permian Cedar Mesa Sandstone At Moki Dugway, Southeastern Utah, David Loope
Plant Root Systems Preserved In The Permian Cedar Mesa Sandstone At Moki Dugway, Southeastern Utah, David Loope
Department of Earth and Atmospheric Sciences: Faculty Publications
Rooted green plants represent the base of the food chain for most terrestrial ecosystems, but, compared to animal burrows, root systems are relatively rarely recognized in ancient sedimentary rocks. Plant roots that penetrate unconsolidated sand dunes, especially those containing not only quartz grains, but also abundant grains of calcite (CaCO3), are commonly replaced by fine crystals of calcite (Klappa, 1980). These structures (known by geologists as rhizoliths from the Greek for “root rock”) are one form of calcite cemented soil and sediment called caliche (figure 1). Caliche crystallizes well above the water table and its calcite crystals are …
Sandstones And Utah’S Canyon Country: Deposition, Diagenesis, Exhumation, And Landscape Evolution, David Loope, Richard Kettler, Kendra Murray, Joel Pederson, Peter Reiners
Sandstones And Utah’S Canyon Country: Deposition, Diagenesis, Exhumation, And Landscape Evolution, David Loope, Richard Kettler, Kendra Murray, Joel Pederson, Peter Reiners
Department of Earth and Atmospheric Sciences: Faculty Publications
South-central Utah’s prominent sandstones and deeply dissected landscapes are the focus of this four-day trip, which begins and ends in Grand Junction, Colorado. Studies of the apatite grains in sandstones adjacent to igneous intrusions are revealing new information on the timing and rate of Cenozoic erosion. Iron-oxide-cemented concretions in other rocks record how reduced-iron carbonates and subsurface microbes interacted when near-surface, oxygenated waters started to flush the reducing, CO2-rich waters from Colorado Plateau aquifers. New geochronologic techniques that are being applied to the plateau rocks have the potential to expand our knowledge of how diagenetic episodes relate to …
Evolution Of The Earliest Horses Driven By Climate Change In The Paleocene-Eocene Thermal Maximum, Ross Secord, Jonathan I. Bloch, Stephen G. B. Chester, Doug M. Boyer, Aaron R. Wood, Scott L. Wing, Mary J. Kraus, Francesca A. Mcinerney, John Krigbaum
Evolution Of The Earliest Horses Driven By Climate Change In The Paleocene-Eocene Thermal Maximum, Ross Secord, Jonathan I. Bloch, Stephen G. B. Chester, Doug M. Boyer, Aaron R. Wood, Scott L. Wing, Mary J. Kraus, Francesca A. Mcinerney, John Krigbaum
Department of Earth and Atmospheric Sciences: Faculty Publications
Body size plays a critical role in mammalian ecology and physiology. Previous research has shown that many mammals became smaller during the Paleocene-Eocene Thermal Maximum (PETM), but the timing and magnitude of that change relative to climate change have been unclear. A high-resolution record of continental climate and equid body size change shows a directional size decrease of ~30% over the first ~130,000 years of the PETM, followed by a ~76% increase in the recovery phase of the PETM. These size changes are negatively correlated with temperature inferred from oxygen isotopes in mammal teeth and were probably driven by shifts …
New Stratigraphic Subdivision, Depositional Environment, And Age Estimate For The Upper Cretaceous Djadokhta Formation, Southern Ulan Nur Basin, Mongolia, Demberelyin Dashzeveg, Lowell Dingus, David B. Loope, Carl C. Swisher Iii, Togtokh Dulam, Mark R. Sweeney
New Stratigraphic Subdivision, Depositional Environment, And Age Estimate For The Upper Cretaceous Djadokhta Formation, Southern Ulan Nur Basin, Mongolia, Demberelyin Dashzeveg, Lowell Dingus, David B. Loope, Carl C. Swisher Iii, Togtokh Dulam, Mark R. Sweeney
Department of Earth and Atmospheric Sciences: Faculty Publications
Studies of key and newly discovered sections of the Upper Cretaceous Djadokhta Formation along the southern margin of the Ulan Nur Basin allow a new subdivision based on lithology. The formation and its members were mapped at both Bayn Dzak, an area that includes the Flaming Cliffs, and Tugrugyin Shireh, an area about 50 km to the northwest of Bayn Dzak. Stratigraphic sections at both localities were remeasured. The considerably enlarged formation comprises a lower Bayn Dzak Member, dominated by moderate reddish orange sands with subordinate mudstone units, and an upper Tugrugyin Member, composed of pale orange to light gray …
Geology Beneath The Primary Management Systems Evaluation Area (Msea) Site Southwest Of Shelton, Buffalo County, Nebraska, Robert F. Diffendal Jr., Frank A. Smith
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 …
Dissociation Quotients Of Oxalic Acid In Aqueous Sodium Chloride Media To 175c, Richard Kettler, Donald A. Palmer, David J. Wesolowski
Dissociation Quotients Of Oxalic Acid In Aqueous Sodium Chloride Media To 175c, Richard Kettler, Donald A. Palmer, David J. Wesolowski
Department of Earth and Atmospheric Sciences: Faculty Publications
The first and second molal dissociation quotienls of oxalic acid were measured potenliometrically in a concentration cell filled with hydrogen electrodes. The emf of oxalic acid-bioxalate solutions was measured relative to an HCI standard solution from 25 to 125°C over 25° intervals at nine ionic strengths ranging from 0.1 to 5.0 molal (NaCl). The molal dissociation quotients and available literature data were treated in the all anionic form by a five-term equation that yielded the following thermodynamic quantities at infinite dilution and 25°C: logKIa = -1.277±0.010, ΔHl̊a = -4.1± 1.1 kJ-mol-1, ΔSl̊a = 38±4 J-K …
Quaternary Geology Of The Northern Great Plains, William J. Wayne, James S. Aber, Sherry S. Agard, Robert N. Bergantino, John P. Bluemle, Donald A. Coates, Maurice E. Cooley, Richard F. Madole, James E. Martin, Brainerd Mears Jr, Roger B. Morrison, Wayne M. Sutherland
Quaternary Geology Of The Northern Great Plains, William J. Wayne, James S. Aber, Sherry S. Agard, Robert N. Bergantino, John P. Bluemle, Donald A. Coates, Maurice E. Cooley, Richard F. Madole, James E. Martin, Brainerd Mears Jr, Roger B. Morrison, Wayne M. Sutherland
Department of Earth and Atmospheric Sciences: Faculty Publications
The Great Plains physiographic province lies east of the Rocky Mountains and extends from southern Alberta and Saskatchewan nearly to the United States-Mexico border. This chapter covers only the northern part of the unglaciated portion of this huge region, from Oklahoma almost to the United StatesCanada border, a portion that herein will be referred to simply as the Northern Great Plains (Fig. 1). This region is in the rain shadow of the Rocky Mountains. Isoheyets are roughly longitudinal, and mean annual precipitation decreases from about 750 mm at the southeastern margin to less than 380 mm in the western and …
Leg 101--An Overview, James A. Austin Jr., Wolfgang Schlager, Amanda A. Palmer, Paul A. Comet, André Droxler, Gregor Eberli, Eric Fourcade, Raymond Freeman-Lynde, Craig S. Fulthorpe, Gill Harwood, Gerhard Kuhn, Dawn Lavoie, Mark Leckie, Allan J. Melillo, Arthur Moore, Henry T. Mullins, Christian Ravenne, William W. Sager, Peter Swart, Joost W. Verbeek, David K. Watkins, Colin Williams
Leg 101--An Overview, James A. Austin Jr., Wolfgang Schlager, Amanda A. Palmer, Paul A. Comet, André Droxler, Gregor Eberli, Eric Fourcade, Raymond Freeman-Lynde, Craig S. Fulthorpe, Gill Harwood, Gerhard Kuhn, Dawn Lavoie, Mark Leckie, Allan J. Melillo, Arthur Moore, Henry T. Mullins, Christian Ravenne, William W. Sager, Peter Swart, Joost W. Verbeek, David K. Watkins, Colin Williams
Department of Earth and Atmospheric Sciences: Faculty Publications
During Leg 101, the inaugural leg of the Ocean Drilling Program, the JOIDES Resolution drilled 19 holes at 11 sites in the Bahamas. Grids of high-resolution seismic profiles provided information crucial for both site selection and regional stratigraphic interpretations. The first major scientific objective was to understand the long-term evolution of the bank-and-basin pattern that currently characterizes the Bahamas archipelago. Drilling and seismic surveys have indicated considerable platform expansion and retreat rather than stationary upward growth. Upbuilding in the Late Jurassic-Early Cretaceous was followed by drowning and retreat in the mid-Cretaceous and by renewed expansion in the Cenozoic. At Site …
Early History Of The Atlantic Ocean And Gas Hydrates On The Blake Outer Ridge: Results Of The Deep Sea Drilling Project Leg 76, Robert E. Sheridan, Felix M. Gradstein, Leo A. Barnard, Deborah M. Bliefnick, Dan Habib, Peter D. Jenden, Hideo Kagami, Everly M. Keenan, John Kostecki, Keith A. Kvenvolden, Michel Moullade, James Ogg, Alastair H.F. Robertson, Peter H. Roth, Thomas H. Shipley, Larry Wells, Jay L. Bowdler, Pierre H. Cotillon, Robert B. Halley, Hajimu Kinoshita, James W. Patton, Kenneth A. Pisciotto, Isabella Premoli-Silva, Margaret M. Testarmata, Richard V. Tyson, David K. Watkins
Early History Of The Atlantic Ocean And Gas Hydrates On The Blake Outer Ridge: Results Of The Deep Sea Drilling Project Leg 76, Robert E. Sheridan, Felix M. Gradstein, Leo A. Barnard, Deborah M. Bliefnick, Dan Habib, Peter D. Jenden, Hideo Kagami, Everly M. Keenan, John Kostecki, Keith A. Kvenvolden, Michel Moullade, James Ogg, Alastair H.F. Robertson, Peter H. Roth, Thomas H. Shipley, Larry Wells, Jay L. Bowdler, Pierre H. Cotillon, Robert B. Halley, Hajimu Kinoshita, James W. Patton, Kenneth A. Pisciotto, Isabella Premoli-Silva, Margaret M. Testarmata, Richard V. Tyson, David K. Watkins
Department of Earth and Atmospheric Sciences: Faculty Publications
Leg 76 of the Deep Sea Drilling Project achieved two major scientific objectives. The first objective was met at Site 533, where on the Blake Outer Ridge, gas hydrates were identified by geophysical, geochemical, and geological studies. Gas-hydrate decomposition produced a volumetric expansion of 20:1 of gas volume to pore-fluid volume; this expansion exceeded by about a factor of four the volume of gas that could be released from solution in pore water under similar conditions. The gas hydrate includes methane, ethane, propane, and isobutane but apparently excluded normal butane and higher molecular weight hydrocarbons as predicted from gas hydrate …
Urban Geology—A Need And A Challenge, William J. Wayne
Urban Geology—A Need And A Challenge, William J. Wayne
Department of Earth and Atmospheric Sciences: Faculty Publications
Urban land uses are rapidly converting open land into intensively used land. Generally, in planning those uses, a comprehensive study has included everything except an evaluation of the land in three dimensions. Geologists are eminently well equipped to supply the missing data, but they must also be aware of the needs of the urban community and the kinds of information needed by planners if they are to write reports usable by planners. Urban and environmental geology is a newly expanding field in the use of geologic data to help solve some urban problems in the planning stage. It is likely …
Pleistocene Formations In Indiana, William J. Wayne
Pleistocene Formations In Indiana, William J. Wayne
Department of Earth and Atmospheric Sciences: Faculty Publications
The system of stratigraphic classification used in North America for all sedimentary rock units except nonmarine deposits of the Pleistocene Series established groups, formations, and smaller units based on objectively determined characteristics of the rocks and not on geomorphology or subjective features, such as geologic time. Not all students of the nonmarine Pleistocene have kept these two kinds of units distinct from each other. The Pleistocene sediments of Indiana and the surrounding States are continental in origin rather than marine, and thus they show far less lithologic homogeneity than sediments and rocks of marine origin. Nevertheless, these Pleistocene sediments can …