Earth Sciences Commons^™

Evaluation Of Pgaa Data For Provenance Of Lithic Artifacts, Otis N. Crandell

Studia UBB Geologia

The objectives of the study were to determine whether Prompt Gamma Activation Analyses (PGAA) could be successfully used to trace the source(s) of various Neolithic artifacts made of microcrystaline quartz. Two macroscopically identical sources of jasper from central and western Romania were analyzed by PGAA along with five Neolithic artifacts from the Limba site (Alba County). Due to the limited number of trace elements, which can be measured by PGAA, this method when used alone might produce inconclusive results for discriminating between jaspers from different sources. The interpretation of the data may be used for general assessments of provenance involving …

Processes Controlling The Composition Of First-Cycle Sediments Deposited In An Arid-Climate, With Implications For Provenance Reconstruction Studies, Aubrey Lynn Modi

Masters Theses

Petrologic analysis of first-cycle clastic sediments derived from a single source in an arid environment provides a means to determine how well they resemble the petrology and geochemistry of their source. The Stepladder Mountains, located in the Mojave Desert of southeastern California, represents a well-controlled location (i.e., arid environment; single, known source; short transport distance) to examine how naturally formed sediments acquire their compositions. Compositional modifications associated with sediment production were resolved through direct examination of the weathered components (regolith, grus, and sediments). Sediment compositions strongly vary by grain size, indicating that, after the source itself, hydrodynamic sorting played the …

Effects Of Sediment Mineralogy To High-Iron Content In The Groundwater Of Rrogozhina Aquifer (Western Albania), Arjan Beqiraj, Enkeleida Beqiraj

Studia UBB Geologia

The groundwater of Rrogozhina aquifer (western Albania) is generally characterized by high iron contents. Its water-bearing medium consists of soft to hard sandstone and conglomerate with intercalations of impermeable clay layers. The groundwater of Rrogozhina aquifer, that extends over a surface of 2100 km² in the pre-Adriatic depression of Albania, occurs under typically artesian conditions. The iron content in ground water ranges from 0.2% up to 2.5%, but most of them fall within the interval 0.5-1.0 %. In groundwater iron occurs as reduced divalent ferrous iron (Fe⁺²) which is conditioned by the lack of water exposure to …

The Formation History Of Layered Chondrules In Acfer-139 (Cr2), Matt Downen

Mahurin Honors College Capstone Experience/Thesis Projects

Chondrules are spherical grains made of silicates and metal that represent some of the oldest materials our solar system. Acfer-139 (CR) is a carbonaceous chondrite with large multilayered chondrules. The multilayered chondrules are composed of a silicate core surrounded by alternating layers of silicates and metals. Serial sectioning was used to analyze the sample in three dimensions. EMPA and LA-ICP-MS were used to create elemental maps of Acfer-139 (CR2) and determine the geochemistry of different layers in each thick section cut. XRCMT was used to construct a 3-D model of a large multilayered chondrule named Ch-1 with concentric layers of …

Trace Element Analysis Of Rutile And Zr-In-Rutile Thermometry For Southern Appalachian Pelitic Schists, Kathryn A. Eccles

Honors Program Projects

Over the past decade, geochronology studies in the southern Appalachians have focused on zircon, monazite, and mica ages to confirm the occurrence of a major Taconic event (~460‐450 Ma) affecting the Western and Central Blue Ridge, followed by a younger NeoAcadian (~360‐345 Ma) event affecting the Eastern Blue Ridge and Piedmont. Peak conditions of granulite facies metamorphism are estimated at ~850°C (garnet‐biotite) and 7‐9 kbar (GASP) for sillimanite schists at Winding Stair Gap (WSG), but thermobarometric studies of metasedimentary rocks in the region are limited and consequently Pressure‐Temperature‐time‐Deformation (P‐T‐t‐D) paths are poorly understood. Many details of the orogenic processes in …

Geochemistry Of The Mt. Persis Volcanics And Evidence For Thickening Of Cascade Crust Over Time, Monica Hanson

Summer Research

The Cascade Range is a classic example of a continental magmatic arc, a belt of igneous activity resulting from subduction of the oceanic Juan de Fuca plate beneath the western margin of the North American plate. The Cascade arc, which started forming about 38 million years ago, is unique in that extensive uplift and erosion have exposed plutonic and volcanic rocks of similar age. This study will focus on the Mt. Persis area in the North Cascades, where a pluton of the Index batholith is surrounded by near-source volcanic rocks and suggests that the volcano may have originated from the …

Implications Of Surface Runoff Recharge In Semi-Arid Regions On Groundwater Sustainability, Omar M. Al-Qudah

Open Access Theses & Dissertations

Amargosa Desert, Nevada regional groundwater studies show that the surface runoff infiltration occurring in the arroyos following runoff producing storms, and this infiltration is considered to be a major source of groundwater recharge. Groundwater infiltration through alluvium was investigated in the Amargosa Desert using borehole drill cuttings, groundwater chemistry, and applying a novel method for collecting runoff water. The sampling process included sediment, precipitation, and runoff water. In total, 176 runoff, 182 sediment, and 45 precipitation samples were collected between January, 2009 and January, 2011.Water chemistry, chloride concentrations, and stable isotopes of water collected from specially designed runoff samplers, placed …

Geochemical Systematics Among Amphibolitic Rocks In The Central Blue Ridge Province Of Southwestern North Carolina, Nathan Collins

USF Tampa Graduate Theses and Dissertations

The Central Blue Ridge sub-province of the southern Appalachian Mountains preserves an unique and complex geologic history. The Cartoogechaye terrane is the westernmost terrane of the Central Blue Ridge sub-province, and is characterized by extensive olistostromal sequences, including mafic-ultramafic massifs, isolated mafic units, and block-in-matrix structures of varying scales. This study investigates the genetic and tectonic relationships, and regional chemical and metamorphic trends of the amphibolitic rocks entrained within units of the Cartoogechaye and nearby terranes, toward constraining the origins of these regional sequences, and examining the rationale for the current Blue Ridge terrane designations.

A distinct compositional variation exists …

The Present Day Genesis And Evolution Of Cave Minerals Inside The Ojo De La Reina Cave (Naica Mine, Mexico), Giovanni Badino, José Maria Calaforra, Paolo Forti, Paolo Garofalo, Laura Sanna

International Journal of Speleology

Ojo de la Reina is the first and the smallest cave intersected at the -290 level in the Naica Mine (Mexico), therefore it was the first cavity in which the lowering of temperature induced by mine ventilation caused condensation over crystals’ surface since 2005. The consequent dissolution of the gypsum crystals and subsequent condensed water evaporation lead to the deposition of several new minerals, among which some highly soluble Mg/Na compounds (bloedite, epsomite, halite, hexahydrite, kieserite, starkeyite). The single available source of Mg and Na ions in this minerogenetic environment is represented by the huge fluid inclusions widespread within the …