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Full-Text Articles in Physical Sciences and Mathematics

Calibration Of Optical Digital Fragmentation Measuring Systems, Norbert H. Maerz, Wei Zhou Jun 2000

Calibration Of Optical Digital Fragmentation Measuring Systems, Norbert H. Maerz, Wei Zhou

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Optical granulometry systems like WipFrag are required to measure fragments in situ. That is to say, the fragments are in piles where sorting takes place, where fragments are partially overlapped, and where fines may not be seen because they fall in and behind the coarser fragments, or where the fines are simply too small to be seen. As a result, optical systems tend typically to overestimate the size of the distribution, and underestimate the variability of the distribution. The wider the size distribution being measured, the more severe the problem is. This paper presents the results of a study that …


Sedimentology, Palynology, And Sea Level Fluctuations Recorded From Two Pennsylvanian Cores From Northwestern Missouri, Elizabeth J. Morris, Francisca Oboh-Ikuenobe Apr 2000

Sedimentology, Palynology, And Sea Level Fluctuations Recorded From Two Pennsylvanian Cores From Northwestern Missouri, Elizabeth J. Morris, Francisca Oboh-Ikuenobe

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Two cores from Buchanan and Andrew Counties in the Forest City Basin, northwestern Missouri, yielded approximately 1,200 feet of sedimentary rock deposited during the Pennsylvanian Period (approximately 300 million years ago), a period characterized by rapid fluctuations in sea level. The cores were logged from the Excello Formation in the Upper Desmoinesian Series upward to the Iatan Formation at the top of the Missourian Series. Lithofacies were identified from rock composition, grain size, color, bedding thickness, sedimentary structures, and fossils. Petrographic thin sections were taken from selected rock types and the results were used to complement the visual descriptions. Limestones …


Analysis Of Deformation Data At Parkfield, California: Detection Of A Long-Term Strain Transient, Stephen S. Gao, Paul G. Silver, Alan T. Linde Feb 2000

Analysis Of Deformation Data At Parkfield, California: Detection Of A Long-Term Strain Transient, Stephen S. Gao, Paul G. Silver, Alan T. Linde

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Analysis of more than a decade of high-quality data, particularly those from the two-color electronic distance meter (EDM), in the Parkfield, California, area reveals a significant transient in slip rate along the San Andreas Fault. This transient consists of an increase in fault slip rate of 3.3 ± 0.9 mm/yr during 1993.0 to 1998.0. The most reliable fault creep instruments show a comparable increase in slip rate, suggesting that the deformation is localized to the fault which breaks the surface. There was also an increase in precipitation around 1993. It is unlikely, however, that this anomaly is due directly to …


Creating Virtual 3-D Outcrop, Xueming Xu, Carlos L. V. Aiken, Janok P. Bhattacharya, Rucsandra M. Corbeanu, Kent C. Nielsen, George A. Mcmechan, Mohamed G. Abdel Salam Feb 2000

Creating Virtual 3-D Outcrop, Xueming Xu, Carlos L. V. Aiken, Janok P. Bhattacharya, Rucsandra M. Corbeanu, Kent C. Nielsen, George A. Mcmechan, Mohamed G. Abdel Salam

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Because of the high precision of present-day GPS and reflectorless laser technology, geologic information and remotely sensed data (i.e., seismic and GPR grids, wells) can be positioned accurately in 3-D and reconstructed as a virtual image. Hence, we have developed the “virtual outcrop” for applications that require knowledge about the 3-D spatial arrangements of rock types.


Dolomitization And Dolomite Neomorphism: Trenton And Black River Limestones (Middle Ordovician) Northern Indiana, U.S.A., M. I N Chan, Jay M. Gregg, Kevin L. Shelton Jan 2000

Dolomitization And Dolomite Neomorphism: Trenton And Black River Limestones (Middle Ordovician) Northern Indiana, U.S.A., M. I N Chan, Jay M. Gregg, Kevin L. Shelton

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The Trenton and Black River Limestones are dolomitized extensively along the axis of the Kankakee Arch in Indiana, with the proportion of dolomite decreasing to the south and southeast of the arch. Planar and nonplanar dolomite replacement textures and rhombic (type 1) and saddle (type 2) void-filling dolomite cements are present. Three stages of dolomitization, involving different fluids, are inferred on the basis of petrographic and geochemical characteristics of the dolomites. Nonferroan planar dolomite has relatively high δ18O values (-1.8 to -6.1‰ PDB) and has 87Sr/86Sr ratios (0.70833 to 0.70856) that overlap those of Middle Ordovician seawater. …