Browsing Geology by Title
Now showing items 133-152 of 172
-
The Seismic Signatures of Recently Formed Impact Craters on Mars
(Journal of Geophysical Research Planets, 2019-09)We investigated the seismic signatures of recent impact crater clusters on Mars that would be recorded by the InSight Seismic Experiment for Interior Structure (SEIS) seismometers. We used a database of 77 measured and ... -
A Semianalytical, Three Dimensional Model of Microstructure in Multiparticle, Multiphase Flow
(2011)This dissertation presents a three dimensional microgeodynamic model of grain-melt geometry in partially molten rocks. The isotropic unit cell of the partially molten rock is characterized by a face-centered-cubic symmetry, ... -
Siderophile elements and molybdenum, tungsten, and osmium isotopes as tracers of planetary genetics and differentiation: Implications for the IAB iron meteorite complex
(2016)Isotopic and trace element abundance data for iron meteorites and chondrites are presented in order to investigate the nature of genetic relations between and among meteorite groups. Nebular and planetary diversity and ... -
Size and shape characteristics of airborne amphibole asbestos and amphibole cleavage fragments
(2015)Data on size and shape characteristics of airborne amphibole asbestos and amphibole cleavage fragments obtained from air-monitoring filters at three mine sites and two industrial sites: (1) Homestake Gold Mine, Lead, South ... -
Size and shape characteristics of amphibole cleavage fragments from milled riebeckite
(2015)Data on size and shape characteristics of riebeckite cleavage fragments. The sample was obtained from the Long Valley Creek Quarry, California. Data were collected in ca. 1978-1979. Data values were obtained with Scanning ... -
Size and shape characteristics of Indian tremolite asbestos
(2016)Size distribution measurements of Indian tremolite asbestos by scanning electron microscopy. This material was characterized by the University of Maryland in collaboration with the US Bureau of Mines as part of studies on ... -
Size and shape characteristics of mountain-leather actinolite
(2016)Size distribution measurements of mountain-leather actinolite by scanning electron microscopy. This material was characterized by the University of Maryland in collaboration with the US Bureau of Mines as part of studies ... -
Size and shape characteristics of South African actinolite asbestos (ferro-actinolite)
(2016)Size distribution measurements of South African actinolite asbestos (ferro-actinolite) by scanning electron microscopy. This material was characterized by the University of Maryland in collaboration with the US Bureau of ... -
Size distribution measurements of amosite, crocidolite, chrysotile, and nonfibrous tremolite
(2015)[Originally uploaded 2015-12-09. Updated 2016-03-24 to add the chrysotile data.] Size distribution measurements of South African amosite, South African crocidolite, chrysotile, and New York tremolite by scanning electron ... -
Skull Cave LiDAR Point Cloud - TubeX
(2021)Archived are Light Detection and Ranging (LiDAR) data collected at Lava Beds National Monument by the NASA funded TUBEX project (Dr. Kelsey Young – PI) and the “LiDAR-Team” in 2017 and 2018. This team was led by Dr. ... -
STABILITY OF RIDGE-RIDGE-RIDGE TRIPLE JUNCTIONS BASED ON THE MECHANICS OF RIFT INTERACTION: THE NORTHERN GALÁPAGOS AND RODRIGUEZ TRIPLE JUNCTIONS
(2010)Although known to be kinematically stable, Ridge-Ridge-Ridge (RRR) triple junctions sometimes display a complex sequence of short-lived rifts and no direct connection between the ridges. The Galápagos Triple Junction, in ... -
Stabilizing Effect of High Pore Fluid Pressure on Slip Behaviors of Gouge-bearing Faults
(2019)We conducted experiments to investigate the influence of pore fluid pressure on the frictional strength and slip behavior of gouge bearing faults. Saw-cut porous sandstone samples with a layer of gouge powders placed between ... -
A Stable Isotope Investigation of Precipitation Nitrate
(2005-08-15)The isotopic composition of precipitation nitrate reflects the processes involved in its formation. Silver nitrates prepared from Maryland precipitation were thermally decomposed to gases for mass spectrometric analyses. ... -
Stable Isotopic Evidence for the Rise of Oxygen and Reorganization of the Sulfur Cycle from the ca. 2.3 Ga Duitschland Formation, South Africa
(2006-12-13)Metasedimentary rocks from the Transvaal Supergroup, South Africa, were used in a stable isotopic study to investigate the evolution of the Earth's early atmosphere and early biogeochemical cycles. Sulfur isotopic evidence ... -
STRUCTURE OF CONTINENTAL LITHOSPHERE FROM TRANSDIMENSIONAL BAYESIAN INVERSION OF SURFACE WAVES AND RECEIVER FUNCTIONS
(2019)Continental crust and the underlying lithospheric mantle make up the continental lithosphere of the Earth. Our understanding of its structure and composition is limited by the inaccessibility of Earth’s deep interior. ... -
A Study of the Sulfur Isotopic Composition of Martian Meteorites
(2012)ABSTRACT Title of Document: A STUDY OF THE SULFUR ISOTOPIC COMPOSITION OF MARTIAN METEORITES Heather B. Franz, Ph.D., 2012 Directed By: Professor James Farquhar, Department of Geology and ESSIC Sulfur is an ... -
SULFUR ISOTOPE CHARACTERIZATION OF MANTLE RESERVOIRS SAMPLED BY OCEAN ISLAND BASALTS
(2020)Ocean islands are volcanic islands in the middle of oceans that are formed when magma deep inside the Earth buoyantly rises to the surface and erupts as basaltic lava (termed Ocean Island Basalt, OIB). Geochemical ... -
Sulfur isotope fractionations in biological systems: insight into the Proterozoic biosphere
(2007-03-26)This study focuses on developing a framework for interpreting isotopic fractionations in the four stable sulfur isotopes, with a special focus on microbial effects. Calculations of low temperature equilibrium fractionations ... -
SULFUR ISOTOPE RECORDS IN NEOARCHEAN CARBONATES: IMPLICATIONS FOR THE EARLY PRECAMBRIAN SULFUR CYCLE
(2017)Mass-independent fractionation of sulfur isotopes found in Early Precambrian records is the main evidence supporting an oxygen-poor atmosphere before ~2.4 Ga when ancient sulfur cycling was different than today. In previous ... -
Sulfur isotopic evolution of Phanerozoic and Ediacaran seawater sulfate
(2013)Dynamics of &sigma34S and &sigma33S of oceanic sulfate and sedimentary pyrite over geologic time has been used to understand and extract information about the marine sulfur cycle. My Ph.D project uses this approach to study ...