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Articles 1 - 6 of 6
Full-Text Articles in Physical Sciences and Mathematics
Strain And Rotation Rate From Gps In Tibet, Anatolia, And The Altiplano, Richard W. Allmendinger, Robert Reilinger, John P. Loveless
Strain And Rotation Rate From Gps In Tibet, Anatolia, And The Altiplano, Richard W. Allmendinger, Robert Reilinger, John P. Loveless
Geosciences: Faculty Publications
Deformation measured by regional GPS networks in continental plateaus reflects the geologic and tectonic variability of the plateaus. For two collisional plateaus (Tibet and Anatolia) and one noncollisional (the Altiplano), we analyze the regional strain and rotation rate by inverting GPS velocities to calculate the full two-dimensional velocity gradient tensor. To test the method, we use gridded velocities determined from an elastic block model for the eastern Mediterranean/Middle East region and show that to a first order, the deformation calculated directly from the GPS vectors provides an accurate description of regional deformation patterns. Principal shortening and extension rate axes, vertical …
Late Cambrian (Steptoean) Sedimentation And Responses To Sea-Level Change Along The Northeastern Laurentian Margin: Insights From Carbon Isotope Stratigraphy, Bosiljka Glumac, Laurel E. Mutti
Late Cambrian (Steptoean) Sedimentation And Responses To Sea-Level Change Along The Northeastern Laurentian Margin: Insights From Carbon Isotope Stratigraphy, Bosiljka Glumac, Laurel E. Mutti
Geosciences: Faculty Publications
Carbon isotopes are applied as tools for stratigraphic correlation of poorly fossiliferous Upper Cambrian carbonate strata in the northern U.S. Appalachians. Upper Cambrian (Steptoean) marine carbonate rocks record a significant global positive carbon isotope excursion (δ 13C = +4‰-5‰ Vienna Peedee belemnite [VPDB]), the timing of which is well documented in fossiliferous sections elsewhere. The Steptoean excursion peaks at a sea-level lowstand that produced the Sauk II-Sauk III sequence boundary on the North American craton. In this study, this excursion is documented for the first time in the northern U.S. Appalachians in poorly exposed limestone debris flow and olistolith deposits …
Paleosalinity History Of Middle Holocene Lagoonal And Lacustrine Deposits In The Enriquillo Valley, Dominican Republic Based On Pore Morphometrics And Isotope Geochemistry Of Ostracoda, Pamela Medley, Neil E. Tibert, William P. Patterson, H. Allen Curran, Lisa Greer, Jean-Paul Colin
Paleosalinity History Of Middle Holocene Lagoonal And Lacustrine Deposits In The Enriquillo Valley, Dominican Republic Based On Pore Morphometrics And Isotope Geochemistry Of Ostracoda, Pamela Medley, Neil E. Tibert, William P. Patterson, H. Allen Curran, Lisa Greer, Jean-Paul Colin
Geosciences: Faculty Publications
The southwestern region of the Dominican Republic (Enriquillo Valley) contains exceptionally well-preserved, relict marine and saline lake deposits of mid-Holocne age. Abundant euryhaline ostracodes found in this deposit include Cyprideis salebrosa, C. mexicana, C. similis, and C. edentata. Morphometric and geochemical analyses performed on Cyprideis spp. provide high δ18O and δ13C values that are coincident with relative abundances of irregularly shaped pores that permeate the ostracode carapace. We recognize three stratigraphic intervals with distinct ostracode pore shape and stable isotope trends: (I) a 4.5-5.0m interval that contains ostracodes with highly irregular shaped pores (multiradiate) and …
Ichnogenic Porosity, High-Frequency Cyclostratigraphy, And Groundwater Flow In The Karst Biscayne Aquifer, Se Florida, Usa, Kevin Cunningham, H. Allen Curran
Ichnogenic Porosity, High-Frequency Cyclostratigraphy, And Groundwater Flow In The Karst Biscayne Aquifer, Se Florida, Usa, Kevin Cunningham, H. Allen Curran
Geosciences: Faculty Publications
No abstract provided.
Ichnofacies, Ichnocoenoses, And Ichnofabrics Of Quaternary Shallow-Marine To Dunal Tropical Carbonates: A Model And Implications, H. Allen Curran
Ichnofacies, Ichnocoenoses, And Ichnofabrics Of Quaternary Shallow-Marine To Dunal Tropical Carbonates: A Model And Implications, H. Allen Curran
Geosciences: Faculty Publications
A model of five ichnocoenoses within the Skolithos and Psilonichnus ichnofacies characterizes the modern, Holocene, and Pleistocene coastal-carbonate depositional environments and limestones of the Bahamas, as well as the Miami Limestone of south Florida. The subtidal to intertidal ichnocosnoses of the Skolithos ichnofacies are dominated by trace-making activities and trace fossils of callianassid shrimp, which can create distinctive and maximum ichnofabrics. Fossil Upogebia vasquezi burrows found in intertidal calcarenites and burrows of the trace fossil Psilonichnus upsilon, most common in beach backshore beds, have excellent potential as stratigraphic markers and can be used as indicators of past sea-level positions. …
Paleoenvironmental Reconstruction Of The Middle Eocene Trieste-Pazin Basin (Croatia) From Benthic Foraminiferal Assemblages, Sanja ŽIvkovic, Bosiljka Glumac
Paleoenvironmental Reconstruction Of The Middle Eocene Trieste-Pazin Basin (Croatia) From Benthic Foraminiferal Assemblages, Sanja ŽIvkovic, Bosiljka Glumac
Geosciences: Faculty Publications
Foraminiferal assemblages from four stratigraphic sections of the Trieste-Pazin basin in central Istria, Croatia (southwestern Tethyan realm) were investigated to reconstruct paleoenvironmental conditions and to determine the age of these deposits. The following five Middle Eocene planktonic foraminiferal zones were identified from the range and frequency of foraminiferal species: Globigerinatheka kugleri/Morozovella aragonensis Zone (E9), Acarinina topilensis Zone (E10), Morozovelloides lehneri Zone (E11), Orbulinoides beckmanni Zone (E12), and Morozovelloides crassatus Zone (E13). A data set of benthic foraminifera relative frequency has been subjected to R- and Q-mode cluster analyses to demonstrate the linkage between taxa distribution and paleoenvironmental gradients. Benthic foraminiferal …