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Structural Framework And Tectonic Implications From Field Investigations In The Ramelau Mountains, Timor-Leste, Tanner A. Nielsen

Theses and Dissertations

Recent advances in petroleum exploration off the southern coast of Timor-Leste and emerging mineral discoveries onshore have underscored the need for a more comprehensive structural understanding of the nation's geology. Although new structural models have been proposed for other parts of Timor, limited progress has been made toward developing detailed models for the Ramelau Mountains, which presents the highest structural relief of the Timor Ranges. Previous mapping in this area has been largely reconnaissance in nature and focused primarily on surface bedrock geology. This study presents a new 1:62,500-scale geologic map and a geometric structural analysis of the Ramelau region …

Spatial And Temporal Patterns Of River Incision And Terrace Deposition In Response To Climate And Tectonics In Southern Taiwan, Dominique M. Shore

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Geologists often look at the Earth’s surface to understand the underlying processes that cause mountain formation. As tectonic forces drive uplift of Earth’s surface, processes of erosion transport sediment to lower elevations. Climate can play a large role in landscape formation as well as increased precipitation, accelerating rates of erosion. Rivers leave markers of landscape evolution through terrace landforms, former river floodplains that are left behind when rivers incise into a valley. To better understand landscape response to uplift, this research investigated the initial linkages between uplift, hillslope erosion (mass wasting) and river incision. At some point, it is thought …

Characterizing The Deformation History Of The Southern Mina Deflection: Field And Structural Studies In The Huntoon Mountains, California-Nevada, Joseph Bodie Mccosby

All Master's Theses

New geologic mapping and structural studies in the Huntoon Mountain area (HMA), California-Nevada document the volcanic and deformation histories across the south-central Mina Deflection (MD). Our work allows us to (a) test whether present-day GPS predicted sinistral slip rates are the same as geologic slip rates in the southern MD, and (b) determine the kinematics of fault slip is transfer through the MD. The HMA exposes primarily Miocene andesitic-dacitic volcanic rocks overlain by the 12.114 ± 0.006 Ma (⁴⁰Ar/³⁹Ar sanidine, Petronis et al., 2019) Tuff of Jack Spring and the 11.399 ± 0.041 Ma (^{40 …}

Structural Evolution And Regional Implications Of The Arrowhead Mine Fault Within The Pahranagat Shear Zone, Nevada, Usa, Michael Dennis Evans

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Basin and Range province is characterized by normal faults associated with

extension, but the occurrence of strike-slip faults and the seismic hazard accompanying

them is less understood. One major strike-slip zone, the Pahranagat shear zone (PSZ),

lies in Lincoln County, Nevada and within the boundary zone between northern Basin

and Range (NBR) and central Basin and Range (CBR) sub-provinces. The PSZ is a 20-

25 km long zone of Cenozoic left-lateral faults. The Arrowhead Mine Fault (AMF) is one

of the three major faults in the PSZ. The western AMF and the faults that surround and

abut it are …

Crustal Thickness Beneath Libya And The Origin Of Partial Melt Beneath As Sawda Volcanic Province From Receiver Function Constraints, Awad A. Lemnifi, Abdelsalam Elshaafi, John Browning, Nassib Aouad, Saad K. El Ebaidi, Kelly K. Liu, Agust Gudmundsson

Mining Engineering Faculty Research & Creative Works

This study investigates crustal thickness and properties within the Libyan region. Results obtained from 15 seismic stations belonging to the Libyan Center for Remote Sensing and Space Science are reported, in addition to 3 seismic stations publically available, using receiver functions. The results show crustal thicknesses ranging from 24 km to 36 km (with uncertainties ranging between ±0.10 km and ±0.90 km). More specifically, crustal thickness ranges from 32 km to 36 km in the southern portion of the Libyan territory then becomes thinner, between 24 km and 30 km, in the coastal areas of Libya and thinnest, between 24 …

Did The Kyrenia Range Of Northern Cyprus Rotate With The Troodos-Hatay Microplate During The Tectonic Evolution Of The Eastern Mediterranean?, Antony Morris, Alastair H.F. Robertson, Mark W. Anderson, Emma Hodgson

School of Geography, Earth and Environmental Sciences

No abstract provided.

A Study On The Geology Of The Ţaga Region (Cluj District), Ioan MâRza

Studia UBB Geologia

The geological formations from Ţaga area (Cluj District) are Sarmatian in age (in outcrops) and Badenian (under surface). Lithologically, they are represented mainly by sands and sometimes fine sediments (clays, marls), interbedded with volcanic tuffs a low fossil content. The Badenian is the host of gas accumulations, concentrated in dome structures.

Vent-Fault Spatial Study Of Selected Volcanic Fields Of Southwestern North America And Mexico, Michelle Leonard

USF Tampa Graduate Theses and Dissertations

Of fundamental concern in volcanic hazard and risk assessment studies of volcanic systems is what role crustal structures might play in the ascent of magma through the crust. What are the processes that govern the spatial distribution and timing of eruptions, especially in populated areas or near sensitive facilities? Many studies have drawn the conclusion that faults play a critical role as easily–exploitable crustal weaknesses along which magma can ascend. Great care must be used when assuming a causative relationship between patterns of vents and faults especially when such relationships may be incorporated into hazard assessment models or other forecasting …

Arkosic Rocks From The San Andreas Fault Observatory At Depth (Safod) Borehole, Central California: Implications For The Structure And Tectonics Of The San Andreas Fault Zone, S. D. Springer, James P. Evans, J. I. Garver, D. Kirschner, Susanne U. Janecke

Geosciences Faculty Publications

The San Andreas Fault Observatory at Depth (SAFOD) drill hole encountered indurated, high-seismic-velocity arkosic sedimentary rocks west of the active trace of the San Andreas fault in central California. The arkosic rocks are juxtaposed against granitic rocks of the Salinian block to the southwest and against fine-grained Great Valley Group and Jurassic Franciscan rocks to the northeast. We identify three distinct lithologic units using cuttings, core petrography, electrical resistivity image logs, zircon fission-track analyses, and borehole-based geophysical logs. The upper arkose occurs from 1920 to 2530 m measured depth (mmd) in the borehole and is composed of five structural blocks …

Petrogenesis And Geochemistry Of Pleistocene And Pliocene Basalt Flows Of The Pine Valley Volcanic Field, Utah And Their Relationship To The Tectonics Of The Utah Transition Zone, Matthew Faust

UNLV Retrospective Theses & Dissertations

The Pine Valley Volcanic Field in southwestern Utah consists of at least 24 mafic lava flows and 10 vents. Eruptions have spanned the past 2.4 m.y. The youngest eruptions at the Snow Canyon and Diamond Valley cones occurred between 1 and 20 ka. Lava flows range in composition from basalt to andesite, and include both alkaline and subalkaline rocks throughout the field. Trace element abundances for the youngest lavas show both oceanic island basalt (OIB) and mid-oceanic ridge basalt (MORB) components in their source. Sr and Nd isotopic ratios exhibit evolved values, spanning a large range from epsilon Nd of …

Temporal Variation Of Seismic B-Values Beneath Northeastern Japan Island Arc, Aimin Cao, Stephen S. Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Analysis of a high quality seismic catalog reveals that the average of seismic b-values in the crust beneath most part of northeastern Japan island arc decreased from 0.86 between 1984 and 1990, to 0.73 between 1991 and 1995. The two areas with the largest decrease are found to be in the same areas where the coupling between the North American and the Pacific plates is the highest, as suggested by a recent geodetic study. In the same time period, the annual seismic moment release increased by 10 times. In addition, there seems to be a corresponding increase in volcanic activities …