Earth Sciences Commons^™

Integrated Studies Of Intracontinental Deformation In The Interior Western Usa, Cretaceous To Recent, Jacob Oliver Thacker

Earth and Planetary Sciences ETDs

The advent of plate tectonic theory satisfactorily explained a number of deformation belts around the world. However intracontinental deformation (deformation inboard of a plate margin) remains poorly understood in plate tectonic models. In order to further our understanding of intracontinental tectonics and its effects, this dissertation examines paleotectonic and neotectonic settings within the interior western USA.

Chapter 1 focuses on late Miocene–Recent deformation inboard of the San Andreas plate margin fault and its role on the integration history of the lower Colorado River. The neotectonic analysis included geometric and kinematic fault data collected in key geologic units to characterize the …

Hazard Identification And Coastal Stratigraphy In Crescent Harbor, Northeast Whidbey Island, Washington, Brian Ostrom

All Master's Theses

Crescent Harbor marsh, on northeastern Whidbey Island, records evidence of co-seismic land-level change 1825 to 1925 cal. yrs. BP. The lithostratigraphy and diatom microfossil assemblages reveal a marsh peat abruptly overlain by intertidal mud, indicating rapid subsidence. Analysis of the modern-day position of depositional facies indicates subsidence from a high marsh to a tidal-flat environment representing an estimated 1.7 m elevation change. The timing of subsidence fits within the dates of a rupture found on the nearby Utsalady Point fault between 1,100 and 2,200 years BP (Johnson et al. 2004). Likely, the stratigraphy at Crescent Harbor records the same event …

Determining The Motion And Location Of The Frenchman Mountain Fault, Las Vegas, Nevada: A Paired Basin Analysis And Structural Analysis, Laura Margaret Eaton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Understanding the evolution of large-scale fault systems remains a challenge to geologists and is of critical importance in understanding the dynamics of larger plate tectonic interactions. I mapped the southwestern Frenchman Mountain Fault (FMF), conducted a basin analysis of units in the footwall of the fault, and measured kinematic indicators along the fault zone in order to constrain fault offset, magnitude, and timing in an attempt to further our understanding of these systems.

My findings include: 1) the presence of vertical and sub-vertical slickenlines on southwest dipping fault surfaces indicative of normal sense offset; 2) relatively little lateral variation in …

Condensed And Expanded Sections In The Lower Mesaverde Clastic Wedge, Campanian Of Wyoming: Evidence For Tectonic Rectification Of Sea Level, Matthew W. Botzler

OES Theses and Dissertations

The stratigraphy of the Cretaceous Western Interior basin indicates that sea level oscillated during the late Cretaceous. The oscillations were polyharmonic, with periods ranging from millions of years to hundred thousands and ten thousands of years. However, there is disagreement over the extent to which sea level change was global in nature and the extent to which it was driven by local uplift or subsidence (tectonism). In orogenic regions where subsidence, sediment supply, and eustatic variation are all affecting sea level, comparisons of high and low frequency cycles can help to sort out forcing mechanisms. Low frequency eustatic sea level …

Stratigraphy And Structure At The Southern End Of Lake Champlain In Benson, Vermont, Jennifer L. Granducci

Geology Theses and Dissertations

Detailed mapping and structural investigations in an area bound to the west by the Grenvillian basement of the Adirondack Mountains and to the east by the allochthonous slates of the Taconic Mountains led to the distinction of a Western Undeformed Zone and an Eastern Deformed Zone. The former is composed of the gently east-dipping shelf sequence of upper Cambrian to lower Ordovician clastics and carbonates which unconformably overlie the Precambrian basement. The latter is characterized by lower to middle Ordovician carbonates, striking roughly north-south and dipping predominantly to the east, which are overlain by well-cleaved shales and slates. The stratigraphic …

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 …

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 …

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 …

Complex Structure And Stratigraphy Of Lower Slices Of The Taconic Allochthon Near Middle Granville, New York, David B. Rowley

Geology Theses and Dissertations

The Precambrian (?) to medial Ordovician rocks of the Taconic Allochthon are characterized by argillaceous and arenaceous sediments with lesser associated carbonates, carbonate breccias, and cherts of predominantly deep-water aspect. These allochthonous rocks tectonically overlie an autochthonous to parautochthonous coeval sequence of dominantly shallow marine clastics and carbonates of the Champlain and Vermont Valley sequences. Facies, thickness, sedimentologic, and paleontologic considerations suggest that these coeval sequences represent a carbonate shelf continental rise pair of the east-facing early Paleozoic Atlantic-type margin of North America. This margin formed by the opening of an ocean in latest Precambrian time. The stratigraphy of the …

Structural Geology Of The Fort Miller, Schuylerville And Portions Of The Schaghticoke 7½' Quadrangles, Eastern New York, And Its Implications In Taconic Geology; And Experimental And Theoretical Studies Of Solution Transfer In Deforming Heterogeneous Systems, William P. Bosworth

Geology Theses and Dissertations

Stratigraphies previously proposed for the Taconic sequence of southern Washington County, eastern New York, have incorrectly defined and positioned lower Cambrian black slate units. The proper sequence of Cambrian (?) through Cambrian lithologies is (terminology from Jacobi, 1977): Bomoseen green wacke, Truthville green slate, Browns Pond black slate, Mettawee purple and green slate, and West Castleton and Hatch Hill black slates. This and the entire Taconic sequence is conformable within the western Giddings Brook slice. The detailed lithostratigraphy reported by Jacobi (1977) and Rowley (1980) in northern Washington County can be followed at least some 45 kilometers to the south …

Structural Studies In The Northern Chester Dome Of East-Central Vermont, Bruce Wallace Nesbit

Geology Theses and Dissertations

Rocks in the Eastern Vermont Sequence are highly metamorphosed and are said to range in age from Precambrian to Siluro-Devonian. The sequence outcrops on Keyes Mountain, about 6km Northwest of Felchville, Vermont, and an area on this mountain about 2km square was mapped in great detail.
The dominant rock type found is quartzofeldspathic gneiss, but schistose gneiss, amphibolite, quartzite and schist also occur. Most of these rocks are layered but layering has been transposed in many places and much of it is probably secondary. Layering and schistosity both dip dominantly to the north at about 25º.
A number of mesoscopic …

Geology Of The Northern Part Of The Ortiz Mountains, Santa Fe County, New Mexico, Otis M. Mcrae

Earth and Planetary Sciences ETDs

The northern part of the Ortiz Mountains of north-central New Mexico consists of a tilted fault block of Cretaceous Mancos shale and Mesaverde formation intruded by latite-andesite porphyry sills and laccoliths and a nepheline-bearing augite manzonite stock. Igneous activity started with the development of a volcanic vent in what is now the central part of the mountains. Volcanic debris from the vent want removed from the area by erosion and provided sedimentary material for the late [ ] Espinaso volcanics of the adjoining areas. Intrusion of the latite-andesite porphyry sills and laccolite followed extrusive igneous activity, as demonstrated by the …