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Cretaceous Calcareous Plankton Biostratigraphy Of Sites 872 Through 879, Elisabetta Erba, Isabella Premoli Silva, David K. Watkins

Department of Earth and Atmospheric Sciences: Faculty Publications

This paper documents the distribution of calcareous nannofossils and planktonic foraminifers in Cretaceous sequences recovered at Sites 872 through 879 drilled on guyots in the central and western Pacific Ocean during Leg 144. Calcareous plankton biostratigraphy allows us to obtain important biostratigraphic age constraints for the onset, development, and demise of shallow-water sedimentation on these guyots.

Site 872 on Lo-En Guyot is the only site at which shallow-water limestones were not recovered during Leg 144. Here, the oldest sediment consists of pelagic limestone infilling fractures within the volcanic substrate. Calcareous plankton biostratigraphy constrains the age of these sediments to Coniacian …

Cretaceous And Paleogene Manganese-Encrusted Hardgrounds From Central Pacific Guyots, David K. Watkins, Isabella Premoli Silva, Elisabetta Erba

Department of Earth and Atmospheric Sciences: Faculty Publications

Manganese-encrusted hardgrounds and associated sediments from four guyots in the western Pacific Ocean were investigated using lithostratigraphic and biostratigraphic examination of thin sections. Biostratigraphic data from manganese-encrusted hardgrounds constrain the age of platform drowning to early middle Eocene for Limalok Guyot, latest Maastrichtian to early Paleocene for Wodejebato Guyot, and middle late Albian for MIT Guyot. Microstratigraphic examination of the hardgrounds reveals a complex Cretaceous and Paleogene history of bioerosion, pelagic sediment accumulation, manganese encrustation, and phosphatization. Fourteen distinct episodes of pelagic sediment accumulation occurred, with five in the Cretaceous, three in the Paleocene, and seven in the Eocene. These …

Impact Of Erosion, Mass Wasting, And Sedimentation On Human Activities In The Río Grande Basin, Jujuy Province, Argentina, Waldo Chayle, William J. Wayne

Department of Earth and Atmospheric Sciences: Faculty Publications

Nearly all dry mountainous regions are affected by severe erosion, floods, and debris flows during times of intense precipitation. The lithology, geologic structure, and climate in Jujuy Province, Argentina combine to place at serious risk the people who live along the Río Grande, the major river that drains the east side of the Cordillera Oriental and the west side of the Sierras Subandinas. Nearly all precipitation falls during summer (January–March) with little during the remainder of the year; most of the basin is semiarid to arid, although the southern end has a humid subtropical climate. Relief is great, as much …

Organic Facies And Maturation Of Jurassic/Cretaceous Rocks, And Possible Oil-Source Rock Correlation Based On Pyrolysis Of Asphaltenes, Scotian Basin, Canada, Prasanta K. Mukhopadhyay, John A. Wade, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

This paper establishes source rock characterization and oil-oil and oil-source rock correlations of selected organic-rich shale source rocks and selected light oils and condensates from Jurassic and Cretaceous formations of the Scotian Basin. Multiple source rocks of Kerogen Types IIA (oil-prone), IIA-IIB (oil- and condensate-prone), IIB (condensate and gas prone), III (gas-prone), and IV (nonsource) are identified in various stratigraphic horizons. Vitrinite reflectance and T_max data indicate variable maturation histories, in different parts of the basin, which are related to differences in lithology-related heat conductivity and the presence of older sediments closer to areas of rifting. Multiple linear regression …

The Dinosaur Blues, Alessandro Montanari, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

(Slow blues in E for voice, guitar, and blues harmonica.)

1) I woke up this morning; saw a big rock in the sky.

I woke up this morning; I knew I was gonna die.

It's the end of an era; I knew I was gonna die.

2) We were much bigger than the rats and fish.

We were the kings on the land and the sea.

But when that stone came down, we disappeared from the scene.

3) 65 million years - it's a date to recall.

65 million years - enough time for you all.

If you …

Effect Of Subsoiling On Yield Of Burley Tobacco, Kenneth L. Wells, Kim D. Strohmeier

Soil Science News and Views

Compaction of tobacco fields caused by overworking or working soils when they are too wet has become a topic of concern to burley producers in recent years. Despite the viewpoint of some producers that annual subsoiling of tobacco fields is a profitable practice, particularly on soils which percolate water slowly, the University of Kentucky College of Agriculture recommends subsoiling only for a defined compaction problem. In such cases, some field studies have shown increased yields of burley to tillage practices that penetrate and shatter the compacted layer. Questions persist, however, about the effectiveness of single shank subsoilers used annually by …

Long-Term, Storm-Dominated Sediment Dynamics Of East Beach And Sandy Point, San Salvador Island, Bahamas, Rebecca L. Beavers, H. Allen Curran, Willian T. Fox

Geosciences: Faculty Publications

Reprinted from: Mark Boardman (ed.), Proceedings of the 7th Symposium on the Geology of the Bahamas and Other Carbonate Regions: San Salvador, Bahamian Field Station

Atrazine And Alachlor Dissipation Rates From Field Experiments, Stephen R. Workman, Andrew D. Ward, Norman R. Fausey, Sue E. Nokes

Biosystems and Agricultural Engineering Faculty Publications

Chemical transport is being monitored in the root zone of three agricultural management systems at the Ohio Management Systems Evaluation Area (OMSEA). Atrazine and alachlor concentration data from soil cores taken to a depth of 0.9 m and partitioned into the increments of 0.0 to 0.15, 0.15 to 0.3, 0.45 to 0.6, and 0.75 to 0.9 m show the herbicides remained in the top 0.15 m of the profile during the 1991 and 1992 growing seasons. The slow movement of herbicides was partly due to below normal rainfall during the period. Since the herbicides have not been transported out of …

Evidence Of Active Dune Sand On The Great Plains In The 19th Century From Accounts Of Early Explorers, Daniel R. Muhs, Vance T. Holliday

United States Geological Survey: Staff Publications

Eolian sand is extensive over the Great Plains of North America, but is at present mostly stabilized by vegetation. Accounts published by early explorers, however, indicate that at least parts of dune fields in Nebraska, Colorado, Kansas, New Mexico, and Texas were active in the 19th century. Based on an index of dune mobility and a regional tree-ring record, the probable causes for these periods of greater eolian activity are droughts, accompanied by higher temperatures, which greatly lowered the precipitationto- evapotranspiration ratio and diminished the cover of stabilizing vegetation. In addition, observations by several explorers, and previous historical studies, indicate …

Recent State Of Stress Change In The Walker Lane Zone, Western Basin And Range Province, United States, Oliver Bellier, Mary Lou Zoback

United States Geological Survey: Staff Publications

The NW to north-trending Walker Lane zone (WLZ) is located along the western boundary of the northern Basin and Range province with the Sierra Nevada. This zone is distinguished from the surrounding Basin and Range province on the basis of irregular topography and evidence for both normal and strike-slip Holocene faulting. Inversion of slip vectors from active faults, historic fault offsets, and earthquake focal mechanisms indicate two distinct Quaternary stress regimes within the WLZ, both of which are characterized by a consistent WNW σ₃ axis; these are a normal faulting regime with a mean σ3 axis of N85 °+ …

Generalized Classification Of Economic Minerals

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.

Bouguer Gravity Map Of Kentucky, G. Randy Keller, Donald C. Adams

Map and Chart--KGS

No abstract provided.

An Assessment Of Water Sources Related To Major Systems Of Agricultural Land Use In Kentucky, Robert L. Blevins, Gerald R. Haszler, Grant W. Thomas, Kenneth L. Wells, William W. Witt

Soil Science News and Views

Recent years have seen a greater public concern about the quality of the nation's water resources. While initial concerns targeted point source pollution, the emphasis in recent years has shifted to non-point source pollution, including the effect of general practices used by fanners in agricultural production systems. Since there was no reliable data base on such effects for Kentucky, the state's General Assembly passed legislation during its 1990 session directing the University ofKentucky's College of Agriculture (UK.CA) to assess the effect of agricultural practices on quality of the state's waters. As part of the efforts undertaken by the UKCA in …

No Tillage Adoption In Grain Crops In Kentucky Counties In 1994, Gerald R. Haszler, Grant W. Thomas

Soil Science News and Views

The no-tillage system, where soils are neither tilled nor cultivated, has a number of advantages. Studies in Kentucky and in other states show much lower erosion under no tillage as compared with conventional tillage. In addition, fuel, machinery, and time savings are all impressive when the no-tillage system is used. There is also a tendency toward better crop yields due to higher water capture and/or conservation that is associated with the mulch of crop residues that is maintained on the soil surface in no tillage.

Should Burley Tobacco Farmers Be Concerned About High Rates Of Nitrogen Fertilizers?, Robert C. Pearce, Gary K. Palmer

Soil Science News and Views

The use of nitrogen (N) fertilizer for tobacco production is necessary because (1) tobacco takes up sizable amounts of N, and (2) most soils cannot provide adequate amounts of N. Rates of fertilizer N recommended by the University of Kentucky for burley tobacco production vary based on past cropping history, and under certain conditions can be as high as 350 lbs. N/A However, since tobacco is a high value crop, and profit margins are high, farmers often apply more N than is recommended as insurance against crop losses. The perception of widespread over-application of fertilizer N has resulted in increased …

Weed Seed In Poultry Litter: Should Farmers Be Concerned, Monroe Rasnake

Soil Science News and Views

Over the years, I have received many calls from farmers who have had unusual weed problems in their fields. Their first thoughts normally are that weed seeds were brought to the fields in crop seed, hay, manure, etc. Some of the same concern has been expressed in regard to using poultry litter on fields. As poultry litter becomes available to more Kentucky farmers, should they be concerned about the possibility it would contain weed seed? The simple answer to the question is "NO" in most situations.

The Effect Of Rate And Source Of Potassium Fertilizer On Cured Leaf Yield Of Burley Tobacco And Leaf Content And Soil Test Levels Of Potassium And Magnesium, Kenneth L. Wells, James E. Dollarhide, Mark Reese

Soil Science News and Views

In response to questions being asked by tobacco growers about the effectiveness of sulfate of potash magnesia (SPM; 21% K₂O and 11% Mg) as coinpared to sulfate of potash (SP; 50% K₂O), field studies were conducted during 1993-1994 to compare the two potassium (K) sources for use on burley tobacco. Any effect of SPM on yield of tobacco should be due to Mg since the only difference between the two sources in kind of nutrient contained is the presence of magnesium (Mg) in SPM. To compare the two K sources, we selected field sites low enough …

High-Carbonate, Low-Silica, High-Calcium Stone In The High Bridge Group (Upper Ordovician), Mason County, North-Central Kentucky, Warren H. Anderson, Lance S. Barron

Information Circular--KGS

The High Bridge Group (Middle Ordovician) of northeastern Kentucky is a major source of limestone and dolomite for construction, agricultural, and industrial stone. These industries require carbonate rocks of high chemical purity. Chemical analyses of foot-by-foot samples from a Mason County core show that three zones of high-calcium and several thick zones of high-carbonate and low-silica stone are present in the High Bridge at a mineable depth. Mason County is located in northeastern Kentucky, on the Ohio River, and offers river access to transportation to the metropolitan Covington-Cincinnati market and the northern portion of the Eastern Kentucky Coal Field for …

Tectonic Development Of Panama, Costa Rica, And The Colombian Andes: Constraints From Global Positioning System Geodetic Studies And Gravity, James N. Kellogg, Victor Vega

Faculty Publications

Global Positioning System (GPS) measurements suggest the existence of a rigid Panama- Costa Rica microplate that is moving northward relative to the stable Caribbean Plate. Northward motion of South America relative to the Caribbean plate is independently suggested by the April 1991 Costa Rica earthquake, active folding in the North Panama deformed belt, and a south-dipping Wadati-Benioff zone beneath Panama. Panama may also be continuing to collide eastward with the northern Andes. Rapid subduction is occurring at the Middle America (72mm/yr), Ecuador (70mm/yr), and Colombia (50mm/yr) trenches. The northern Andes are moving northeastward relative to stable South America. Preliminary GPS …

Depositional History, Environments Of Deposition, And Hydrocarbon Potential Of The Newcastle Formation (Lower Cretaceous) Of Eastern North Dakota, Gerald G. Mccloskey

Theses and Dissertations

The Newcastle Formation (Albian) in North Dakota is composed primarily of fine grained sandstone, mudstone and shale. This study examined the Newcastle within the eastern two thirds of North Dakota, with the goal of determining the various depositional environments, the depositional history, and the hydrocarbon potential of the unit. A total of 2191 geophysical well logs and 21 lithologic cores were examined. Isopach maps of the Newcastle Formation and the Skull Creek Shale were generated, as was a structural top map of the Mowry Shale.

The depositional history of the unit is directly linked to the regression and subsequent transgression …

Prey Selectivity By Naticid Gastropods From Tertiary Sediments Of The United States Coastal Plain, Robert N. Sickler

Theses and Dissertations

Previous studies have shown that naticid gastropod predators are highly selective of prey species in accordance with the Kitchell et al. (1981) cost-benefit model. In addition, earlier studies have demonstrated selectivity of drillhole siting and intraspecific prey size. This study focuses on prey selectivity by Oligocene naticid gastropods and is used to test Vermeij's (1987) hypothesis of escalation. The hypothesis of escalation states that biologic hazards have increased during the Phanerozoic and that organisms have either had to adapt to these hazards or face possible extinction (Vermeij, 1987). Naticid predation on molluscan assemblages is one of several examples used to …

Reading The Rangeland: A Guide To The Arid Shrublands Of Western Australia, Don Burnside, Alec Holm, Alan Payne, Georgina Wilson

All other publications

Managing the rangelands is complex. Soils and vegetation can vary considerably over short distances in distinct or subtle ways. Separating climatic from management influences on the condition of the land has always been difficult. Whether we live on a sheep station, in a country town, in an Aboriginal community, a mining camp, or even if we only visit the Australian outback, it is vital that we understand and appreciate the unique character and management requirements of the rangelands. Learning to ‘read the rangeland’ has been a slow process, involving the knowledge and skills of pastoralists, Aboriginal people and scientists. This …

Stratigraphy And Structure At The Southern End Of Lake Champlain In Benson, Vermont, Jennifer L. Granducci

Geology Theses and Dissertations

Detailed mapping and structural investigations in an area bound to the west by the Grenvillian basement of the Adirondack Mountains and to the east by the allochthonous slates of the Taconic Mountains led to the distinction of a Western Undeformed Zone and an Eastern Deformed Zone. The former is composed of the gently east-dipping shelf sequence of upper Cambrian to lower Ordovician clastics and carbonates which unconformably overlie the Precambrian basement. The latter is characterized by lower to middle Ordovician carbonates, striking roughly north-south and dipping predominantly to the east, which are overlain by well-cleaved shales and slates. The stratigraphic …

Carbonate Deposition, Pyramid Lake Subbasin, Nevada: 2. Lake Levels And Polar Jet Stream Positions Reconstructed From Radiocarbon Ages And Elevations Of Carbonates (Tufas) Deposited In The Lahontan Basin, Larry Benson, Michaele Kashgarian, Meyer Rubin

United States Geological Survey: Staff Publications

Most of the tufas in the Pyramid Lake subbasin were deposited within the last 35,000 yr, including most of the mound tufas that border the existing lake. Many of the older tufas (> 21,000 yr B.P.) contained in the mounds were formed in association with ground-water discharge. The radiocarbon (¹⁴C) ages of the older tufas represent maximum estimates of the time of their formation. Lake Lahontan experienced large and abrupt rises in level at ~ 22,000, 15,000, and 11,000 yr B.P. and three abrupt recessions in level at ~ 16,000, 13,600, and 10,000 yr B.P. The lake-level rises …

Fault Healing Inferred From Time Dependent Variations In Source Properties Of Repeating Earthquakes, Chris Marone, John E. Vidale, William L. Ellsworth

United States Geological Survey: Staff Publications

We analyze two sets of repeating earthquakes on the Calaveras fault to estimate in-situ rates of fault strengthening (healing). Earthquake recurrence intervals t, range from 3 to 803 days. Variations in relative moment and duration are combined to study changes in stress drop, rupture dimension, rupture velocity, and particle velocity as a function of t_r. Healing rates and source variations are compared with predictions of laboratory derived friction laws. Two interpretations of event duration τ are used: one in which τ: is given by the ratio of slip to particle velocity and one in which it scales as …

Conglomerates Of The Upper Middle Eocene To Lower Miocene Sespe Formation Along The Santa Ynez Fault: Implications For The Geologic History Of The Eastern Santa Maria Basin Area, Jeffrey L. Howard

Environmental Science and Geology Faculty Research Publications

The depositional history of the Sespe Formation was studied using sedimentary facies analysis, clast counts, paleocurrent and clast morphological measurements, and petrographic methods. Sedimentation is interpreted to have occurred mainly as part of two depositional sequences in a coastal-braid-plain forearc-basin setting. Both sequences are present in the Santa Ynez Mountains, whereas only the upper sequence is recognized in the eastern Santa Maria basin. The lower sequence is part of a late middle to late Eocene sedimentary offlap attributed to a high input of terrigenous sediment derived mostly from the Mojave Desert region. This sequence is capped by an intraformational erosional …

Freezing And Thawing Of Agricultural Soils: Implications For Soil, Water, And Air Quality, Brenton S. Sharratt, Keith E. Saxton, Jerry K. Radke

Journal of the Minnesota Academy of Science

Most agricultural lands in the USA are subject to subfreezing temperatures. Soil freezing and thawing affects both biotic and abiotic interactions and processes which vary with weather, soil type, land management, and topography. Soil fauna generally undergo physiological changes or rely on locomotion as a means of adapting to frozen soils. Managing faunal populations using soil management may be achievable with a better understanding of winter ecological processes. Many of the thermal, hydraulic, mechanical, and physical properties of soils are altered by freezing and thawing. Soil erosion may be accentuated by soil freezing and thawing as a result of changes …

Studies On Freezing And Thawing Soils In Iowa, Jerry K. Radke, Edwin C. Berry

Journal of the Minnesota Academy of Science

Frozen soils have a major influence on the cropping systems and farming practices in northern states. However, relatively little research has been done on the physical, chemical, and biological processes that occur in the field during the non-growing season. Experiments on frozen soils were started recently in Iowa to 1) study the effects of residue cover on soil freezing and thawing, 2) measure the movement of water and solutes and changes in soil structure due to freezing and thawing of repacked soil columns in the field, 3) test the SHAW (Simultaneous Heat And Water) model for its capability to predict …

Frost Tillage For Soil Management In The Northeastern Usa, Harold M. Van Es, Robert R. Schindelbeck

Journal of the Minnesota Academy of Science

Tillage during the winter is typically considered impossible, despite its desirability in some cases. Soil freezing results in net upward movement of water to the freezing zone which facilitates primary tillage or incorporation of amendments. these can be performed during a time window when the frost layer is sufficiently thin to be ripped and the underlying soil is tillable. We evaluated the feasibility of frost tillage and performed an agronomic comparison with spring-tilled soil. Soil conditions conductive to frost tillage occurred during three time windows in the 1991/1992 and two in the 1992/1993 winter at Ithaca, NY. Frost tillage resulted …

Frozen Soils: A Perspective On Past And Future Research For Promoting Sustainable Agricultural Systems, Jerry K. Radke, Brenton S. Sharratt, W. Doral Kemper, Dale A. Bucks

Journal of the Minnesota Academy of Science

Frozen soils impact many industries which rely· on soil, water, and .air resources in developing and manufacturing products. Most noteworthy is the agricultural industry in the northern United States where soils, which sustain food and fiber production, are subjected to frequent freezing and thawing. Soil freezing and thawing influences soil erodibility, surface and ground water quality, air quality, and biological activity. Many strides toward understanding frozen soil processes and managing lands to minimize the adverse effects of freezing and thawing have been made over the last two decades. Yet, further efforts to identify frozen soil processes which influence wind and …