Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 187 for “"Cambrian"”.
-
Stratigraphy and sedimentology, Cambrian Shady Dolomite, Virginia
Cambrian Shady Dolomite facies exposed northwest and southeast of Austinville, southwestern Virginia, apparently formed in a platform-to-basin setting. Northwest of Austinville, the Shady Dolomite (600 m thick) overlies the Lower Cambrian Erwin Formation and is overlain by the Middle Cambrian Rome …
-
Geochemical investigations of the late early Cambrian extinctions
Following the radiation of animals in the early Cambrian, the reef-building archaeocyathids went extinct around 513 – 508 Ma and redlichiid and olenellid trilobites went extinct around 506 Ma. Both extinction events have been documented to occur with negative carbon isotope excursions (CIEs) that …
-
Lower Cambrian bioherms in central Nevada and eastern California
… study was made of two approximately coeval Lower Cambrian bioherm complexes, one in the Ravenswood area of Lander County in central Nevada, and the other in the Montenegro Member of the Campito Formation in the White-Inyo Range of eastern California. Although both bioherm complexes were …
-
Chemostratigraphy of the Uppermost Cambrian Below the Ordovician GSSP
… Stratotype Section and Point (GSSP) of the Cambrian‒Ordovician boundary is located at Green Point in the Green Point Formation of the Cow Head Group in western Newfoundland, Canada. To reconstruct a continuous and high-resolution chemostratigraphy from the Cambrian‒Ordovician boundary to the …
-
Stratigraphy of Cambrian and Ordovician Formations of Northeastern Illinois
Made available in DSpace on 2014-12-04T19:13:53Z (GMT). No. of bitstreams: 1 6000155.pdf: 6181598 bytes, checksum: 2319cb49fe049d26cdf81eea0f9c610e (MD5) Previous issue date: 1959
-
Wall rock alteration accompanying Canadian Pre-Cambrian gold mineralization
Thesis: Ph. D., Massachusetts Institute of Technology, Department of Geology, 1935
-
Contributions to the Proterozoic and Cambrian Evolution of Eukaryotes
… to improve our understanding of Proterozoic-Cambrian evolution of eukaryote life. Chapter 1 provides, for the first time, a quantitative characterization of the evolutionary trends of Proterozoic macroalgae. The analysis reveals that morphological disparity of Paleoproterozoic macroalgae was …
-
The sedimentology of the cambrian clastic sediments of Northwest Scotland
The Cambrian clastic sediments of northwest Scotland crop-out along the line of the Moine Thrust Zone between Skye in the south and Loch Eriboll in the north and form the basal 250m of a broadly transgressive Cambro-Ordovician sequence of clastic and carbonate sediments. These sediments were …
-
Cambrian and Ordovician Conodonts From the Big Horn Mountains, Wyoming
Made available in DSpace on 2014-12-04T19:14:20Z (GMT). No. of bitstreams: 1 6303226.pdf: 3178146 bytes, checksum: 552f549560195bf2dc446a24634893c0 (MD5) Previous issue date: 1962
-
Petrography of the Upper Cambrian Dolomites of Warren County, New Jersey
Made available in DSpace on 2014-12-04T19:14:00Z (GMT). No. of bitstreams: 1 6100224.pdf: 6295129 bytes, checksum: f409c1678ac352424509936fd0f4fe20 (MD5) Previous issue date: 1960
-
The Vendian-Cambrian system of Siberia : correlation, tectonics and petroleum geology
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1997.
-
Analysis of cyclic shallow-water carbonates: Cambrian Highland Peak Formation, eastern Nevada
… level signals recorded in Middle to lower Upper Cambrian shallow-water carbonate rocks in the southwestern United States and to refine stratigraphic correlation of this interval. Embedded Markov chain and cycle architectural analysis define the high-frequency accommodation signal, whereas cycle …
-
A revision of helicoplacoids and other early Cambrian echinoderms of North America
The Lower Cambrian rocks of North America contain the remains of several species of echinoderms, including helicoplacoids, the eocrinoids Gogia, Lepidocystis, and Kinzercystis, and the edrioasteroids Camptostroma and Stromatocystites. Camptostroma roddyi Ruedemann, 1933 is a large echinoderm from …
-
The Cambrian: Sedimentary controls on marine ichnology and stratigraphic time at outcrop
The Cambrian Period represents a pivotal chapter in Earth’s history, marked by the expansion of vast epeiric seas and major evolutionary innovations associated with the Cambrian Explosion. Evolutionary reconstructions can be influenced by sedimentary processes, which were heterogeneous across …
-
Earliest Cambrian - latest Proterozoic ichnofossils and problematic fossils from Inyo County, California
… and problematic body fossils was made from Lower Cambrian to Upper Proterozoic (<em>sensu</em> Cloud, 1973) strata of Inyo County, California. Specimens were collected from the Wyman, Reed, Deep Spring, and Campito Formations in the White-Inyo Mountains and compared to material from the correlated …
-
Hydrocarbon biomarkers for biotic and environmental evolution through the Neoproterozoic-Cambrian transition
The sequence of events over the Neoproterozoic - Cambrian transition that led to the radiation of multicellular organisms has been an issue of debate for over a century. It is a critical interval in the history of life on Earth because it marks the first appearance of all extant animal phyla in the …
-
A multiproxy investigation of oceanic redox conditions during the Cambrian SPICE event
… availability across a portion of the later Cambrian noted for unique evolutionary dynamics and which includes a significant global oceanographic event known as the SPICE event (Steptoean Positive Carbon Isotope Excursion). Previous studies have revealed the SPICE caused large changes to the …
-
Storm-dominated Lower Cambrian depositional environments in the Ravenswood area, Lander County, Nevada
A Lower Cambrian sedimentary sequence 40 meters thick is exposed in the Ravenswood area, Lander County, Nevada. This sequence is divided into 7 lithofacies which are interpreted to represent marine, littoral to sublittoral environments including offshore bars, sheet deposits (proximal, …
-
Petrography and Diagenesis of Cambrian Dolomite in Tabei Uplift, Northern Tarim Basin, China
… most productive hydrocarbon reservoirs. The late Cambrian strata in the Tabei Uplift present a succession of restricted platform and platform margin carbonates, which are mostly dolomitized. Based on an integrated multidisciplinary approach which incorporated one hundred and fourteen meters of …
Page 1 of 10