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Geological And Thermal Aspects Of The Southern San Joaquin Basin, California: Application Of The 40ar/39ar Stepwise Heating Technique To Detrital Microclines, Kenneth Bé
Geology Theses and Dissertations
The depositional history of the southernmost region of the trough-shaped San Joaquin Basin spans from Upper Eocene to Recent time. The stratigraphy reveals both a predominantly marine environment which persisted until the Upper Pliocene, as well as nonmarine environments along the basin's margins. Folds and faults within the basin have resulted directly from movements along the San Andreas fault. Although the exact time of origin of the Big Bend is unclear, this major feature in the San Andreas fault's geometry has played an important role in recent crustal tectonics of southern California. Significantly, the southern San Joaquin's depocenter has undergone …
Geology Of The Fondo Negro Region, Dominican Republic, J. Calvin Cooper
Geology Of The Fondo Negro Region, Dominican Republic, J. Calvin Cooper
Geology Theses and Dissertations
Detailed geologic mapping of the Fondo Negro-Sierra de Martin Garcia region of the Southwestern Dominican Republic establishes that this area is part of a broad and diffuse Northern Caribbean plate boundary zone (PBZ). Faulting in the study area is predominantly left lateral strike-slip, with secondary compression (thrusting) causing both substantial, and rapid, uplift of the region. Folding associated with the wrench faulting affects rocks of all ages in the field area from Paleocene limestones to Quaternary alluvial fans.
New stratigraphic designations are proposed for mappable litho-units in the area, and these are correlated with Hispaniola stratigraphy in general based on …
The Pre-Tertiary Geology And Mesozoic Tectonic Evolution Of Eastern China, Southeast Asia And Adjacent Regions, Michael P. Klimetz
The Pre-Tertiary Geology And Mesozoic Tectonic Evolution Of Eastern China, Southeast Asia And Adjacent Regions, Michael P. Klimetz
Geology Theses and Dissertations
Several orogenic belts transecting south-eastern Asia are the sites of former convergent plate margins although there have been varying interpretations of the collisional framework of individual continental blocks, styles of convergence at these zones and the timing of respective collisions. A comprehensive tectonic study of eastern China, Mongolia and the southern Soviet Far East indicates the collision of the South China Block with a combined North China-Northeast China Fold Zone Block in the late Triassic-early Jurassic, their collective suturing to Eurasia in the late Jurassic-early Cretaceous, followed by the Sikhote Alin-Japan Block in the mid to late Cretaceous. The evidence …
Structure And Stratigraphy Of West Haven, Vermont, Christoph K. Steinhardt
Structure And Stratigraphy Of West Haven, Vermont, Christoph K. Steinhardt
Geology Theses and Dissertations
Mapping and structural investigations in an area bounded to to the west by by Grenvillian basement and to the east by allochthonous rocks emplaced during the medial Ordovician Taconic Orogeny led to division of the area into a Western Undeformed Zone and an Eastern Deformed Zone. The former consists of a thin, undeformed shelf sequence of upper Cambrian to lower Ordovician (Canadian) clastics and carbonates, which unconformably overlie Grenvillian basement and dip gently to the east.
The Eastern Deformed Zone consists of early to medial Ordovician carbonates folded about northnortheast trending axes with east to southeast dipping axial surfaces, overlain …
Geology Of The Western Boundary Of The Taconic Allochthon Near Troy And The Anastomosing Cleavage In The Taconic Melange, Zong-Guo Xia
Geology Of The Western Boundary Of The Taconic Allochthon Near Troy And The Anastomosing Cleavage In The Taconic Melange, Zong-Guo Xia
Geology Theses and Dissertations
The Taconic Allochthon is located in eastern New York, western Vermont, western Massachusetts, and western Connecticut and extends about 200 kilometers north-south and east-west for about 25 kilometers. It contains rocks of Late Proterozoic, Cambrian and Ordovician age. The rocks are predominantly slates with lesser amounts of arenites, wackes, limestone, chert, and conglomerates. All rocks have been subjected to chlorite or biotite grade metamorphism and at least two generations of deformation. The emplacement of the Taconic Allochthon onto the coeval shelf took place during the Middle Ordovician Taconic Orogeny.
The study area lies at the western margin of the Taconic …
Structure And Tectonics Of The Keban Metamorphics In The Northern Margin Of The Bitlis Suture Zone, Southeastern Turkey, Gültekin Savci
Structure And Tectonics Of The Keban Metamorphics In The Northern Margin Of The Bitlis Suture Zone, Southeastern Turkey, Gültekin Savci
Geology Theses and Dissertations
The study area near Keban consists of the allochthonous Keban division of the Keban-Malatya crystalline complex and the Yuksekova island-arc rocks of the Bitlis-Puturge Complex in the northern margin of the Bitlis Suture Zone. Detailed mapping shows that the Palaeozoic-Triassic Keban Metamorphics are composed of the following formations: (1) white, massive, karstic Kirklar Marble; (2) phyllitic psammite with calcschist interlayers Calik Formation; and (3) semi-crystallized gray Koyunatlayan Limestone. These formations define a tectonostratigraphy with the Kirklar Marble at the base and the Koyunatlayan Limestone at the top. The detailed lithological description of the Keban Metamorphic rock assemblages suggest that they …