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Earth Sciences

Selected Works

Selected Works

2005

Articles 1 - 15 of 15

Full-Text Articles in Physical Sciences and Mathematics

Runoff Production In The Upper Rio Chagres Watershed, Panama, Fred Ogden Dec 2004

Runoff Production In The Upper Rio Chagres Watershed, Panama, Fred Ogden

Fred L. Ogden

Runoff production in tropical watersheds is governed by a wide variety of potential sources and there have been few rigorous studies to date. The 414 km2 upper Río Chagres basin offers a unique opportunity to better understand the runoff production mechanisms in tropical watersheds through data analysis and modeling with rainfall and runoff data. Flow data and tipping bucket rain gage data are available at both the basin outlet (Chico gage) and for an 80.6 km2 internal basin location (Piedras gage). Modeling is performed using the Sacramento Soil Moisture Accounting Model (SAC-SMA), calibrated using data from 2000 and verified using …

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Storm Deposited Fish Debris In The Cretaceous Mowry Shale Near Vernal, Utah, Alvin Anderson, Bart Kowallis Dec 2004

Storm Deposited Fish Debris In The Cretaceous Mowry Shale Near Vernal, Utah, Alvin Anderson, Bart Kowallis

Bart J Kowallis

Isolated, lens-shaped accumulations of fi sh bones, scales, teeth, and coprolites in a sandy matrix occur along a few bedding planes within the Cretaceous Mowry Shale in an outcrop along Highway 191 north of Vernal, Utah. These accumulations have previously been interpreted to be large coprolites or regurgitate material, but are actually storm lag deposits in a sediment-starved basin. Accumulations (lenses) vary in size: the largest measured is 15 x 10 cm in plan view and 2 cm thick. Matrix in these lenses consist of fine-grained, well-rounded quartz grains that are absent in the surrounding shale layers. The disarticulated fossil …

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Refining The Geologic Time Scale: An Integrated Biostratigraphic Approach., Daniel Goldman Dec 2004

Refining The Geologic Time Scale: An Integrated Biostratigraphic Approach., Daniel Goldman

Daniel Goldman

Funding agency: Petroleum Research Fund Amount: $50,000.00 Investigator: Dr. Goldman, S.A. Leslie Year: 2005/3 yrs

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Overview Of Radiometric Ages In Three Allochthonous Belts Of Northern Venezuela: Old Ones, New Ones, And Their Impact On Regional Geology, V Sisson, H Lallemant, M Ostos, Ann Blythe, L Snee, P Copeland, J Wright, R Donelick, L Guth Dec 2004

Overview Of Radiometric Ages In Three Allochthonous Belts Of Northern Venezuela: Old Ones, New Ones, And Their Impact On Regional Geology, V Sisson, H Lallemant, M Ostos, Ann Blythe, L Snee, P Copeland, J Wright, R Donelick, L Guth

Ann Blythe

No abstract provided.

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Exploring The Persistence Of Sorted Bedforms On The Inner-Shelf Of Wrightsville Beach, North Carolina, Benjamin Gutierez, George Voulgaris, Robert Thieler Dec 2004

Exploring The Persistence Of Sorted Bedforms On The Inner-Shelf Of Wrightsville Beach, North Carolina, Benjamin Gutierez, George Voulgaris, Robert Thieler

George Voulgaris

Geological studies offshore of Wrightsville Beach, North Carolina reveal subtle large-scale regions of coarse sand with gravel and shell hash (widths between 100 and 200 m and negative relief of ∼1 m) that trend obliquely to the coast. It was previously suggested that these regions serve as conduits for sand exchange between the shoreface and inner shelf during storm-associated downwelling. Consequently they were classified as rippled scour depressions. More recently, the role of alongshore flows and self-organization as a result of inhibited settling of fine sand has been discussed. In this study, 45 days of near-bed current measurements were analyzed …

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Fracturing In A Reverse Drag Fold, Parashant Canyon, Az, Phillip Resor, Patrick Welsh Dec 2004

Fracturing In A Reverse Drag Fold, Parashant Canyon, Az, Phillip Resor, Patrick Welsh

Phillip G Resor

The western Grand Canyon is a natural laboratory for investigating processes of continental extension due to the great vertical exposure (> 1 km) and the relatively simple pre-extensional structure. We have undertaken a detailed field study of joint frequency in Parashant Canyon, a natural cross-section through the normal fault related Lone Mountain monocline, in order to better understand the role that joints play in accommodating extensional folding. The Lone Mountain monocline is made up of two half-monoclinal flexures: a hanging wall fold in which dips gradually increase toward the fault from a regional dip of 2° to a maximum dip …

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Effect Of Channel Bifurcation On Residual Estuarine Circulation: Winyah Bay, South Carolina, Yong Kim, George Voulgaris Dec 2004

Effect Of Channel Bifurcation On Residual Estuarine Circulation: Winyah Bay, South Carolina, Yong Kim, George Voulgaris

George Voulgaris

The residual circulation pattern of Winyah Bay, the fourth largest estuary on the eastern coast of the US, is examined using stationary and shipborne current measurements during periods of low freshwater discharge. The estuary has a complex morphology with a single channel and narrow banks at the river entrance and the bay mouth, and a bifurcated channel system (main and western channels, respectively) in the middle part that appears to affect the residual circulation. Overall, the upper (single channel morphology) and middle (dual-channel morphology) parts of the estuary exhibit a baroclinic residual circulation. The presence of bifurcated channels in the …

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Refining The Geologic Time Scale:An Integrated Biostratigraphic Approach, Daniel Goldman Dec 2004

Refining The Geologic Time Scale:An Integrated Biostratigraphic Approach, Daniel Goldman

Daniel Goldman

Funding agency: UDRI Seed Grant Amount: $9,000.00

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Sustainable Development And Natural Governance: The Challenges Ahead, John Dernbach, Dan Tarlock Dec 2004

Sustainable Development And Natural Governance: The Challenges Ahead, John Dernbach, Dan Tarlock

John C. Dernbach

No abstract provided.

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Targets, Timetables And Effective Implementing Mechanisms: Necessary Building Blocks For Sustainable Development, John C. Dernbach Dec 2004

Targets, Timetables And Effective Implementing Mechanisms: Necessary Building Blocks For Sustainable Development, John C. Dernbach

John C. Dernbach

No abstract provided.

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Integrating High-Precision Aftershock Locations And Geodetic Observations To Model Coseismic Deformation Associated With The 1995 Kozani-Grevena Earthquake, Greece, Phillip G. Resor, David Pollard, T J. Wright, G C. Beroza Dec 2004

Integrating High-Precision Aftershock Locations And Geodetic Observations To Model Coseismic Deformation Associated With The 1995 Kozani-Grevena Earthquake, Greece, Phillip G. Resor, David Pollard, T J. Wright, G C. Beroza

Phillip G Resor

We integrate high-precision aftershock locations with geodetic inverse modeling to create a more complete kinematic model for the Kozani-Grevena earthquake sequence. Using the double-difference algorithm, we have improved relative hypocentral locations by a factor of ∼7 and thus imaged the details of the fault network associated with the seismic sequence. The interpreted fault network consists of multiple segments including (1) a master normal fault that strikes nearly due west and dips toward the north at 43°, extending from 6 to 15 km depth; (2) an upper segment that connects the top of the seismicity to the observed surface ruptures and …

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Inverting For Slip On Three-Dimensional Fault Surfaces Using Angular Dislocations, Phillip G. Resor, David Pollard, Frantz Maerten, Laurent Maerten Dec 2004

Inverting For Slip On Three-Dimensional Fault Surfaces Using Angular Dislocations, Phillip G. Resor, David Pollard, Frantz Maerten, Laurent Maerten

Phillip G Resor

The increasing quality of geodetic data (synthetic aperture radar interferometry [INSAR] dense Global Positioning System [GPS] arrays) now available to geophysicists and geologists are not fully exploited in slip-inversion procedures. Most common methods of inversion use rectangular dislocation segments to model fault ruptures and therefore oversimplify fault geometries. These geometric simplifications can lead to inconsistencies when inverting for slip on earthquake faults, and they preclude a more complete understanding of the role of fault geometry in the earthquake process. We have developed a new three-dimensional slip-inversion method based on the analytical solution for an angular dislocation in a linear-elastic, homogeneous, …

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Hartford Basin Cross Section – Southington To Portland, Ct, Phillip G. Resor, J Z. Deboer Dec 2004

Hartford Basin Cross Section – Southington To Portland, Ct, Phillip G. Resor, J Z. Deboer

Phillip G Resor

No abstract provided.

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Laramie Peak Shear System, Central Laramie Mountains, Wyoming, Usa: Regeneration Of The Archean Wyoming Province During Palaeoproterozoic Accretion, Phillip G. Resor, Arthur W. Snoke Dec 2004

Laramie Peak Shear System, Central Laramie Mountains, Wyoming, Usa: Regeneration Of The Archean Wyoming Province During Palaeoproterozoic Accretion, Phillip G. Resor, Arthur W. Snoke

Phillip G Resor

The Laramie Peak shear system (LPSS) is a 10 km-thick zone of heterogeneous general shear (non-coaxial) that records significant tectonic regeneration of middle-lower crustal rocks of the Archean Wyoming province. The shear system is related to the 1.78–1.74 Ga Medicine Bow orogeny that involved the collision of an oceanic-arc terrane (Colorado province or Green Mountain block or arc) with the rifted, southern margin of the Wyoming province. The style and character of deformation associated with the LPSS is distinctive: a strong, penetrative (mylonitic) foliation commonly containing a moderately steep, SW-plunging elongation lineation. In mylonitic quartzo-feldspathic gneisses of the Fletcher Park …

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Western End Of The Honey Hill Fault Along The Eastern Bank Of The Connecticut River, Phillip G. Resor, J Z. Deboer Dec 2004

Western End Of The Honey Hill Fault Along The Eastern Bank Of The Connecticut River, Phillip G. Resor, J Z. Deboer

Phillip G Resor

No abstract provided.

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