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2019

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Articles 1441 - 1470 of 1657

Full-Text Articles in Earth Sciences

New Fossil Wood Descriptions From The Pliocene Of Central Anatolia And The Presence Of Taxodioxylon In Turkey From The Oligocene To Pliocene, Ünal Akkemi̇k Jan 2019

New Fossil Wood Descriptions From The Pliocene Of Central Anatolia And The Presence Of Taxodioxylon In Turkey From The Oligocene To Pliocene, Ünal Akkemi̇k

Turkish Journal of Earth Sciences

Recent paleobotanical studies on petrified woods revealed valuable information about the Miocene-period trees of Turkey. The purpose of this study is to present new descriptions from the Pliocene of central Anatolia. The materials were collected from a new fossil site of Pliocene age in the village of Yıprak (Çerkeş, Çankırı, Turkey) in central northern Turkey. With this study, a new fossil genus, Cercioxylon Ü. Akkemik, related to modern Cercis L., and a new fossil species of Cupressinoxylon were described, and a long presence of taxodioid type trees from the late Oligocene to Pliocene of Turkey were discussed. The wood composition …


Late Quaternary Landscape Evolution Of The Southern Marmara Region:Paleogeographic Implications For Settlements, Nw Turkey, Ni̇zametti̇n Kazanci, Zeynep Ergun, Kaan İren, Suzanne A. Leroy, Sonay Boyraz Aslan, Mehmet Sali̇m Öncel, Koray Koç, Alper Gürbüz Jan 2019

Late Quaternary Landscape Evolution Of The Southern Marmara Region:Paleogeographic Implications For Settlements, Nw Turkey, Ni̇zametti̇n Kazanci, Zeynep Ergun, Kaan İren, Suzanne A. Leroy, Sonay Boyraz Aslan, Mehmet Sali̇m Öncel, Koray Koç, Alper Gürbüz

Turkish Journal of Earth Sciences

This study presents the late Quaternary evolution of the southern Marmara region in northwestern Turkey and discusses the suitability of the area for settlements. It is based on interpretation of sediment analyses together with radiometric dates obtained from drilling cores. As three-fourths of the southern Marmara region (ca. 30,000 km2) is covered by the Susurluk Drainage Basin (SDB), the study focuses on this basin. The SDB has a concave surface morphology dipping northward, with highlands in the south (ca. 1300-1700 m a.s.l.) and lowlands in the north (ca. 0-250 a.s.l.). Lake Manyas, Lake Ulubat, and south-north flowing rivers, together with …


Small Benthic Foraminiferal Biostratigraphy And Palaeoecology During The Campanian-Maastrichtian Transition In North-Western Tunisia, Abdellatif Bejaoui, Ezzedine Saïdi, Dalila Zaghbib-Turki Jan 2019

Small Benthic Foraminiferal Biostratigraphy And Palaeoecology During The Campanian-Maastrichtian Transition In North-Western Tunisia, Abdellatif Bejaoui, Ezzedine Saïdi, Dalila Zaghbib-Turki

Turkish Journal of Earth Sciences

Campanian-Maastrichtian (C-M) sediments in the Kalâat Senan area (north-western Tunisia) include rich microfauna. Small benthic foraminifera (SBF) analysis at the Wadi Necham (ON) section reveals significant biostratigraphic and palaeoecological changes during the C-M transition. A progressive evolutionary trend within the Bolivinoides lineage allowed us to establish the late Campanian B. decoratus Interval Range Zone (IRZ) and two successive zones in the early Maastrichtian, namely the B. miliaris IRZ and the B. draco Total Range Zone (TRZ), which span the standard planktonic foraminifera Gansserina gansseri IRZ. Foraminiferal semiquantitative data from the C-M transition interval at the studied section yield high values …


Deep Structure Of Central Menderes Massif: Data From Deep Geothermal Wells, Fatma Gülmez, Emre Damci, Umut Bariş Ülgen, Aral Okay Jan 2019

Deep Structure Of Central Menderes Massif: Data From Deep Geothermal Wells, Fatma Gülmez, Emre Damci, Umut Bariş Ülgen, Aral Okay

Turkish Journal of Earth Sciences

The Menderes Massif is a major Alpide metamorphic complex in western Turkey; it is subdivided into southern, central, and northern submassifs by the east-west trending grabens. The basement of the southern Menderes Massif consists of Neoproterozoic micaschists (Selimiye Formation) intruded by Neoproterozoic granites. The basement is overlain by Permo-Carboniferous phyllite, marble, and quartzite (Göktepe Formation), which pass up into a thick sequence of Mesozoic marbles with emery horizons (Milas Marble). The marbles are overlain by latest Cretaceous recrystallized pelagic limestone and Paleocene metaclastics, which are thrusted over by the Lycian nappes. The metamorphism and deformation of the Phanerozoic sequence of …


Structure Of The Büyük Menderes Graben Systems From Gravity Anomalies, Emre Ti̇mur, İlknur Kaftan, Coşkun Sari, Müjgan Şalk Jan 2019

Structure Of The Büyük Menderes Graben Systems From Gravity Anomalies, Emre Ti̇mur, İlknur Kaftan, Coşkun Sari, Müjgan Şalk

Turkish Journal of Earth Sciences

The Büyük Menderes Graben (BMG) of western Turkey is bounded by E-W oriented normal faults and has been a depositional center for thick sedimentary layers since the Miocene. Four Mio-Pliocene depressions (from west to east, the Çine, Bozdoğan, Karacasu, and Denizli basins) having overall N-S trends are situated just south of the BMG. In this study, we focused on the structural characteristics of the BMG using Bouguer gravity data covering the area between 37°N and 39°N and 26°30'E and 30°E and gravity data along 4 profiles to estimate the discontinuous basement relief of the BMG. Our main objectives were to …


The Early Eocene Ekmekçi Granodiorite Porphyry In The Karacabey Region(Sakarya Zone, Nw Turkey), Gürsel Sunal, Mehmet Korhan Erturaç, Gülteki̇n Topuz, Aral Okay, Thomas Zack Jan 2019

The Early Eocene Ekmekçi Granodiorite Porphyry In The Karacabey Region(Sakarya Zone, Nw Turkey), Gürsel Sunal, Mehmet Korhan Erturaç, Gülteki̇n Topuz, Aral Okay, Thomas Zack

Turkish Journal of Earth Sciences

The Ekmekçi granodiorite porphyry is a unit in the E-W trending, postcollisional Eocene magmatic rocks of northern Anatolia. It occurs as a relatively small stock, but represents a link between plutonic and volcanic rocks. This Early Eocene granodiorite porphyry intruded into the Upper Triassic rocks of the Karakaya complex in the Sakarya Zone. In this study we present geochemical and zircon U-Pb LA-ICP-MS age data to contribute to understanding the Early Tertiary postcollisional tectonic setting of NW Anatolia. The granodiorite porphyry includes plagioclase, quartz, hornblende, K-feldspar, biotite, and minor zircon, apatite, sphene, and opaque minerals. The stock displays medium-K calc-alkaline …


Petrological Characteristics Of The Middle Eocene Toveireh Pluton (Southwest Of Jandaq, Central Iran): Implications For The Eastern Branch Of The Neo-Tethys Subduction, Masumeh Sargazi, Ghodrat Torabi, Tomoaki Morishita Jan 2019

Petrological Characteristics Of The Middle Eocene Toveireh Pluton (Southwest Of Jandaq, Central Iran): Implications For The Eastern Branch Of The Neo-Tethys Subduction, Masumeh Sargazi, Ghodrat Torabi, Tomoaki Morishita

Turkish Journal of Earth Sciences

The Middle Eocene Toveireh plutonic body is located in the western margin of the Central-East Iranian Microcontinent (CEIM). This plutonic body consists of granodiorite, syenogranite, and monzogranite compositions. Granodiorite is the most predominant rock unit, which is composed of quartz, plagioclase, K-feldspar, hornblende, and biotite main mineral phases. The Toveireh pluton is metaluminous to weakly peraluminous (A/CNK = 0.85-1.04) and shows a calc-alkaline I-type affinity. Primitive mantle-normalized spidergrams show enrichment of large ion lithophile elements (Rb, Ba, Th, U) and light rare earth elements (REEs) (La/YbN = 6.8-8.24), as well as depletion of high-field strength elements (Nb, Ta, Ti, P). …


Petrography, Geochemistry, And Provenance Of Jurassic Sandstones From Thesakarya Zone, Nw Turkey, Firat Şengün, Osman Ersi̇n Koralay Jan 2019

Petrography, Geochemistry, And Provenance Of Jurassic Sandstones From Thesakarya Zone, Nw Turkey, Firat Şengün, Osman Ersi̇n Koralay

Turkish Journal of Earth Sciences

The Jurassic sandstones exposed in the western part of the Sakarya Zone are yellowish to brown, moderate to well sorted, medium to coarse-grained, grain-supported, and cemented by calcareous and minor silica. Sandstones are mainly classified as litharenite, subarkose, and arkose according to the relative proportions of quartz, feldspar and rock fragments, and major element ratios. On the SiO2 variation diagram, Na2O and K2O show slight positive correlations, which could reflect abundance of sodic plagioclase and K-feldspar with quartz within high Si-content sandstones. Sandstones generally exhibit slight LREE enrichment with respect to HREEs. The REE plots are characteristic for sedimentary rocks …


Geology, Fluid Inclusion, And Stable Isotope (O, H, S, C) Characteristics Of The Hazinemağara (Gümüşhane) Lead-Zinc Deposit, Ne Turkey, Esra Ünal Çakir, Ahmet Gökce Jan 2019

Geology, Fluid Inclusion, And Stable Isotope (O, H, S, C) Characteristics Of The Hazinemağara (Gümüşhane) Lead-Zinc Deposit, Ne Turkey, Esra Ünal Çakir, Ahmet Gökce

Turkish Journal of Earth Sciences

The Hazinemağara (Gümüşhane) Pb-Zn deposit is located in the southern part of the Eastern Pontides Orogenic Belt in northeastern Turkey. It occurs as irregularly shaped ore bodies with breccia fill structure within the intraformational breccia or brecciated horizons of limestone in the Upper Jurassic-Lower Cretaceous Berdiga Formation. The dominant ore minerals are pyrite, sphalerite, galena, and tetrahedrite, and the major gangue minerals are calcite, quartz, and barite. Microthermometric investigations of the fluid inclusions show that the ore-forming fluids contain CaCl2 and MgCl2 in addition to NaCl. The salinity of the fluid ranges from 1.7% to 9.2% with an average of …


New Insights On Messinian Evaporites Based On Field And Seismic Interpretations In The Neogene Antalya Basin, Sw Turkey, Sali̇ha Dündar, Baki̇ Erdoğan Varol Jan 2019

New Insights On Messinian Evaporites Based On Field And Seismic Interpretations In The Neogene Antalya Basin, Sw Turkey, Sali̇ha Dündar, Baki̇ Erdoğan Varol

Turkish Journal of Earth Sciences

In situ/primary Messinian upper evaporite is absent in the onland (onshore) sections of the Aksu and Manavgat subbasins (Antalya Basin), where gypsum blocks, gypsum conglomerate, and laminated gypsum beds mixed with siliciclastic materials are collectively present in the uppermost Messinian-?lowermost Pliocene succession. The metric-size resedimented evaporite blocks, mainly derived from selenite-dominated marginal/upper evaporite, were deposited time-equivalent to the lower-middle parts of the reefal Gebiz limestone in the Aksu subbasin. Resedimented bedded evaporites were accumulated after siliciclastic-dominated (fluvio-deltaic) sedimentation of the Taşlık Formation in the Manavgat subbasin (nearby Antalya city). Some bedded/?resedimented gypsums were defined within the Gebiz limestone and the …


The Mineralogical And Geochemical Composition Of Holocene Sediments From Lake Hazar, Elazığ, Eastern Turkey: Implications For Weathering, Paleoclimate, Redox Conditions, Provenance, And Tectonic Setting, Di̇cle Bal Akkoca, Kürşad Kadi̇r Eri̇ş, Memet Namik Çağatay, Demet Bi̇lteki̇n Jan 2019

The Mineralogical And Geochemical Composition Of Holocene Sediments From Lake Hazar, Elazığ, Eastern Turkey: Implications For Weathering, Paleoclimate, Redox Conditions, Provenance, And Tectonic Setting, Di̇cle Bal Akkoca, Kürşad Kadi̇r Eri̇ş, Memet Namik Çağatay, Demet Bi̇lteki̇n

Turkish Journal of Earth Sciences

Mineralogical and geochemical analyses of samples collected from piston core HZ11-P01 at the western margin of Lake Hazar were studied to determine the provenance and weathering conditions on the source area together with tectonic setting of the source rocks, paleoclimate of the region, and paleo-redox conditions of the lake sediments. Nonclay minerals in the sediment core are represented by feldspar, quartz, dolomite, and calcite. The clay mineral assemblage consists of smectite/chlorite mixed-layer clay, chlorite, and illite. Most major, trace, and rare earth element contents of the lake samples are generally similar to those of the catchment area. Chondrite-normalized rare earth …


Parameter Estimations From Gravity And Magnetic Anomalies Due To Deep-Seated Faults:Differential Evolution Versus Particle Swarm Optimization, Yunus Levent Eki̇nci̇, Çağlayan Balkaya, Gökhan Göktürkler Jan 2019

Parameter Estimations From Gravity And Magnetic Anomalies Due To Deep-Seated Faults:Differential Evolution Versus Particle Swarm Optimization, Yunus Levent Eki̇nci̇, Çağlayan Balkaya, Gökhan Göktürkler

Turkish Journal of Earth Sciences

Estimation of causative source parameters is an essential tool in exploration geophysics and is frequently applied using potential field datasets. Naturally inspired metaheuristic optimization algorithms based on some stochastic procedures have attracted more attention during the last decade due to their capability in finding the optimal solution of the model parameters from the parameter space via direct search routines. In this study, the solutions obtained through differential evolution algorithm, a rarely used metaheuristic algorithm in geophysics, and particle swarm optimization, which is one of the most used global optimization algorithms in geophysics, have been compared in terms of robustness, consistency, …


Frequency-Dependent Body-Q And Coda-Q In Karlıova Triple Junction And Its Vicinity,Eastern Turkey, Alper Demi̇rci̇ Jan 2019

Frequency-Dependent Body-Q And Coda-Q In Karlıova Triple Junction And Its Vicinity,Eastern Turkey, Alper Demi̇rci̇

Turkish Journal of Earth Sciences

A dataset obtained from six broadband stations of 111 small- to moderate-sized local events that occurred between 2010 and 2018 was analyzed to reveal the frequency-dependent seismic body (body-Q) and coda (coda-Q) wave attenuation characteristics of three tectonic branches of the Karlıova Triple Junction: the Varto Fault Zone (VFZ), North Anatolian Fault Zone (NAFZ), and East Anatolian Fault Zone. The magnitude range was between 2.8 and 6.1 with shallow (


Mineralogy, Petrology And Geochemistry Of Mafic Dikes In The Southeast Jebal-E-Barezgranitoids (Bam, Kerman Province, Iran): Studies From Mafic Dikes Formed In Avolcanic Arc-Setting, Shirin Behpour, Abbas Moradian, Hamid Ahmadipour, Kazuo Nakashima Jan 2019

Mineralogy, Petrology And Geochemistry Of Mafic Dikes In The Southeast Jebal-E-Barezgranitoids (Bam, Kerman Province, Iran): Studies From Mafic Dikes Formed In Avolcanic Arc-Setting, Shirin Behpour, Abbas Moradian, Hamid Ahmadipour, Kazuo Nakashima

Turkish Journal of Earth Sciences

In the southeastern part of the Jebal-E-Barez Oligocene granitoids (Kerman province, Iran), there are numerous mafic dikes and this work attempts to investigate the petrological, geochemical and mineral chemistry of these dikes. The dikes clearly follow faults which trend mainly N50-70W and N20-40W. Their thicknesses vary from 1 cm to 3 m and their contacts with the host granitic rocks are sharp without any extensive contact metamorphism which may be due to the lack of magmatic fluids. The Jebal-E-Barez mafic dikes contain plagioclase, clinopyroxene and amphibole as major minerals and overall show porphyritic texture, but intergranular, ophitic and subophitic textures …


Investigating Seismic Deformation Associated With The Aging And Subduction Of Oceanic Lithosphere Using Teleseismic Earthquake Relocation And Insar Techniques, Kevin Kwong Jan 2019

Investigating Seismic Deformation Associated With The Aging And Subduction Of Oceanic Lithosphere Using Teleseismic Earthquake Relocation And Insar Techniques, Kevin Kwong

Earth Sciences Theses and Dissertations

Based on seismicity and deformation patterns, the evolution and subduction of oceanic lithosphere can be divided into three domains: 1) the incoming oceanic lithosphere plate, 2) the megathrust plate boundary, and 3) the down-going slab. Well-located hypocenters illuminate fault complexity in space and time and verify details of surface deformation within or associated with the subduction system. This dissertation presents high-resolution earthquake catalogs derived using teleseismic double-difference (DD) relocation to best resolve earthquakes in absolute space, while providing relative locations for more detail fault studies. In the Wharton Basin, a new earthquake catalog allows more detailed examination of complex oceanic …


Geochemical Analysis Of Soil And Lake Deposits As Indicators Of Paleoenvironmental Conditions; Examples From Texas, New Mexico, And D.R. Congo, Mary Milleson Jan 2019

Geochemical Analysis Of Soil And Lake Deposits As Indicators Of Paleoenvironmental Conditions; Examples From Texas, New Mexico, And D.R. Congo, Mary Milleson

Earth Sciences Theses and Dissertations

Geochemical proxies of paleoenvironmental conditions are presented from studies of modern lacustrine deposits from White Rock Lake, Dallas Texas, Upper Pennsylvanian through Lower Permian paleosols from Mora County New Mexico, and Upper Paleozoic lacustrine strata from the Congo Basin, D.R. Congo.

The composition of sedimentary organic matter of White Rock Lake is utilized to establish a temporal relationship between urbanization of the local watershed and lake system. Geochemical proxies of watershed conditions allow for the evaluation of changes in lake morphometry, which are correlated with historical records of urbanization. The δ13C and C/N values of sedimentary organic matter …


Scanning Electron Microscope Study Of Microstructure And Regeneration Of Upper Pennsylvanian Cladid Crinoid Spines, Hannah Smith, James Thomka Jan 2019

Scanning Electron Microscope Study Of Microstructure And Regeneration Of Upper Pennsylvanian Cladid Crinoid Spines, Hannah Smith, James Thomka

Williams Honors College, Honors Research Projects

The crinoid skeleton is characterized by a complicated, highly porous microstructure known as stereom. Details of stereomic microstructural patterns are directly related to the distribution and composition of connective tissues, which are rarely preserved in fossils. However, certain portions of the crinoid skeleton have never been studied with respect to stereomic microstructure. In particular, spines are common features on the crowns of many Paleozoic crinoids but had not previously been studied in detail with respect to stereomic microstructure. This study focused on pirasocrinid cladid crinoids, a common group with numerous identifiable crown spines, including spines on the arms and anal …


Long-Term Land Management Practices And Their Effect On Soil Health And Crop Productivity, Thomas Joseph Muratore Jr. Jan 2019

Long-Term Land Management Practices And Their Effect On Soil Health And Crop Productivity, Thomas Joseph Muratore Jr.

Theses and Dissertations--Plant and Soil Sciences

Agricultural intensification reliant on monocrops could change soil health in a way that does not support maximum crop productivity. Twenty-nine-year-old no-till field plots at the University of Kentucky Spindletop research farm showed a significant reduction in corn yields from continuous corn plots compared to those from plots in various types of rotation. The objective of this study was to determine what role soil microbes might play in yield reduction and how management and time effects microbial community structure. Samples were collected from the following treatments: continuous corn (CC), continuous soybean (SS), a 2-year corn/soybean rotation (CCSS), Corn in rotation with …


Delivering Sustained, Coordinated, And Integrated Observations Of The Southern Ocean For Global Impact, Louise Newman, Petra Heil, Rowan Tebilco, Katsuro Katsumata, Andrew Constable, Esmee Van Wijk, Karen Assmann, Joana Beja, Phillippa Bricher, Richard Coleman, Daniel Costa, Steve Diggs, Riccardo Farneti, Sarah Fawcett, Sarah T. Gille, Katharine R. Hendry, Sian Henly, Eileen Hofmann, Ted Maksym, Matthew Mazloff, Andrew Meijers, Michael M. Meredith, Sebastien Moreau, Burcu Ozsoy, Robin Robertson, Irene Schloss, Oscar Schofield, Jiuxin Shi, Elisabeth Sikes, Inga J. Smith, Sebastiaan Swart, Anna Wahlin, Guy Williams, Michael J. M. Williams, Laura Herraiz-Borreguero, Stefan Kern, Jan Lieser, Robert A. Massom, Jessica Melbourne-Thomas, Patricia Miloslavich, Gunnar Spreen Jan 2019

Delivering Sustained, Coordinated, And Integrated Observations Of The Southern Ocean For Global Impact, Louise Newman, Petra Heil, Rowan Tebilco, Katsuro Katsumata, Andrew Constable, Esmee Van Wijk, Karen Assmann, Joana Beja, Phillippa Bricher, Richard Coleman, Daniel Costa, Steve Diggs, Riccardo Farneti, Sarah Fawcett, Sarah T. Gille, Katharine R. Hendry, Sian Henly, Eileen Hofmann, Ted Maksym, Matthew Mazloff, Andrew Meijers, Michael M. Meredith, Sebastien Moreau, Burcu Ozsoy, Robin Robertson, Irene Schloss, Oscar Schofield, Jiuxin Shi, Elisabeth Sikes, Inga J. Smith, Sebastiaan Swart, Anna Wahlin, Guy Williams, Michael J. M. Williams, Laura Herraiz-Borreguero, Stefan Kern, Jan Lieser, Robert A. Massom, Jessica Melbourne-Thomas, Patricia Miloslavich, Gunnar Spreen

CCPO Publications

The Southern Ocean is disproportionately important in its effect on the Earth system, impacting climatic, biogeochemical, and ecological systems, which makes recent observed changes to this system cause for global concern. The enhanced understanding and improvements in predictive skill needed for understanding and projecting future states of the Southern Ocean require sustained observations. Over the last decade, the Southern Ocean Observing System (SOOS) has established networks for enhancing regional coordination and research community groups to advance development of observing system capabilities. These networks support delivery of the SOOS 20-year vision, which is to develop a circumpolar system that ensures time …


Pursue Undergraduate Research Journal Volume 2 (Issue 1) 2019 Jan 2019

Pursue Undergraduate Research Journal Volume 2 (Issue 1) 2019

Pursue: Undergraduate Research Journal

The scholarly journal, “PURSUE: Undergraduate Research Journal” (ISSN 2473-6201), provides undergraduates an avenue to publish their original research abstracts and articles in the following areas: psychology, sociology, biology, chemistry, physics, engineering, computer science, mathematics, humanities, agriculture, architecture, health, business, and education (this list is not exclusive).

The original research articles included in this journal are peer reviewed and selected by the journal’s Editorial Board. The review process allows undergraduate researchers to receive feedback from notable scientists in their field of study and teach them about the publication process. Publication of their work will not only inform the scientific community; it …


Effects Of Initial Thermal Structure On The Evolution Of Continental Rifting, Alexandra Wernle Jan 2019

Effects Of Initial Thermal Structure On The Evolution Of Continental Rifting, Alexandra Wernle

All Master's Theses

Continental rifting is a fundamental earth process that displays a wide variety of styles ranging from narrow to wide, symmetric and asymmetric, magmatic and amagmatic. The key conditions and processes that control the evolution of rifts remain enigmatic. Previous research suggests that the initial thermal structure may have a first order control on the evolving styles of these systems. This project examines the impact of the initial thermal structure on the spatial and temporal evolution of continental rifts using finite element thermo-mechanical modeling. The initial thermal structure is a product of crustal heat production rates and heat conducted from the …


Defining Historical Earthquake Rupture Parameters And Proposed Slip Distributions Through Tsunami Modeling In South-Central Chile, Alexander Dolcimascolo Jan 2019

Defining Historical Earthquake Rupture Parameters And Proposed Slip Distributions Through Tsunami Modeling In South-Central Chile, Alexander Dolcimascolo

All Master's Theses

Reliable tsunami early warning forecasts rely on accurate initial modeling conditions and interpretations of subduction zone behavior in a multi-century perspective. GPS and seismologic data were introduced this past century to study rupture dynamics in detail, however limited information is known about ruptures that pre-date the 20th century. I propose a methodology that uses statistics to better understand these pre-20th century ruptures. This methodology applies the historical and geologic tsunami record as a means to select a suite of tsunami simulations from earthquake source solutions. I chose south-central Chile (46°S to 30°S) to test this new methodology; it …


Holocene Fire History Reconstruction Of A Mid-Evaluation Mixed-Conifer Forest In The Eastern Cascades, Washington, Zoe Rushton Jan 2019

Holocene Fire History Reconstruction Of A Mid-Evaluation Mixed-Conifer Forest In The Eastern Cascades, Washington, Zoe Rushton

All Master's Theses

Fire histories of mid-elevation mixed-conifer forests (MEMC) are uncommon, particularly in the eastern Cascades of Washington. As a result, fire regimes and the effects of 20th century fire suppression in these forests are not well understood. In the summer of 2014 a 7.80 meter-long sediment core was extracted from Long Lake, located approximately 45 km west of Yakima, WA, which exists in a grand fir-dominated mixed-conifer forest. Fire activity for the Long Lake watershed was reconstructed using macroscopic charcoal analysis and pollen analysis was used to reconstruct vegetation change through time. Charcoal results show low fire activity in the early …


Identifying Key Factors Affecting Translational Landslides In Part Of The Yakima Fold And Thrust Belt, Washington State, Joseph Schilter Jan 2019

Identifying Key Factors Affecting Translational Landslides In Part Of The Yakima Fold And Thrust Belt, Washington State, Joseph Schilter

All Master's Theses

Washington has one of the fastest growth rates in the nation, and unfortunately also is among the most landslide-prone states. With increased population density and urban sprawl, the need for landslide hazard assessment grows. On the Columbia Plateau in central Washington, the smooth rigid, inclined surfaces of the Columbia River Basalts (CRBs) with loose sediment layers between them induces landslides of large blocks of bedrock. These hazards remain poorly understood, but their significance was heightened by the 2017 Rattlesnake Hills Landslide that currently threatens a community and an interstate highway south of Yakima, Washington. I propose that the strongest influences …


Seasonal Soil Carbon Fluxes In Transitioning Agricultural Soils In Central Washington State: Relations To Land-Use, Environmental Factors And Soil Carbon-Nitrogen Characteristics, Brandon Kautzman Jan 2019

Seasonal Soil Carbon Fluxes In Transitioning Agricultural Soils In Central Washington State: Relations To Land-Use, Environmental Factors And Soil Carbon-Nitrogen Characteristics, Brandon Kautzman

All Master's Theses

Changing agricultural land-use practices to increase soil carbon sequestration contributes to climate change mitigation and improved food security by moving CO2 from the atmosphere into soil as soil organic carbon (SOC). In 2016, a farm in Thorp, Washington, Spoon Full Farm, began converting land historically farmed using conventional methods of tillage and synthetic fertilizers to conservation farming methods with direct seeding and organic soil amendments with a goal of sequestering carbon in the soil. This project evaluates relationships of soil CO2 respiration and net ecological exchange (NEE) with land-use types, seasonal environmental factors (air temperature, relative humidity, soil …


Mapping And Reconstructing The Paleotsunami Record In Queule, South-Central Chile, Pedro I. Matos Llavona Jan 2019

Mapping And Reconstructing The Paleotsunami Record In Queule, South-Central Chile, Pedro I. Matos Llavona

All Master's Theses

Records of past tsunamis help constrain the long-term characteristics of megathrust earthquakes and elucidate the role of sea-level in the preservation of tsunami deposits. Near Queule, south-central Chile (39.3˚S, 73.2˚W), three sand layers interpreted as tsunami deposits are interbedded with dark, organic-rich, silt deposits along a tidal channel landward of a sand spit capped by eolian sand dunes. The uppermost sand layer is attributed to the tsunami from the Mw 9.5 1960 earthquake. The sand layer is widespread, tabular, oxidized, thins landward, and generally occurs at a depth of <20 cm. The spatial distribution of the deposit corresponds closely with the extent of the 1960 tsunami sand on 1961 aerial photographs. We computed numerical simulations of the 1960 tsunami in Queule using the GeoClaw finite-slip hydrodynamic model based on three published earthquake sources. The simulations showed inundation up to 4km inland that overtopped the coastal dunes; agreeing with historical documentation and testimonies of 1960 tsunami survivors. Stratigraphically below the 1960 tsunami deposit are two tabular, landward-thinning sand layers with sharp lower contacts above silty organic-rich layers. Combined radiocarbon ages of seeds, charcoal and wood fragments found at the contacts with the underlying organic layers yielded ages of 5460-5320 and 5990-5910 cal. years BP. These sand layers have similar distribution patterns to the 1960 sand layer, but are finer grained, thinner and less oxidized. Below this sequence of interbedded tsunami sands and silty organic layers there is an abrupt contact underlain by a distinct sequence of four inorganic silt layers alternating with dark brown organic-rich silts, which are older than 6280-6110 cal. years BP. The deepest studied layer is a thick, fine, gray sand. We interpret the gray sand as a submarine environment during the mid-Holocene sea-level high stand, and the alternating inorganic and organic silts as tidal to shallow sub-tidal environments, possibly indicating co-seismic land-level changes. Gradual sea level fall after the deposition of the two paleotsunami sand deposits that changed the geomorphology of the coast and limited the accommodation space necessary to preserve additional overwash sediments could explain the 5000-year hiatus with no evidence of earthquakes or tsunamis. Further research will offer possible explanations for the exception of the 1960 tsunami in breaking this long-term pattern.


Characterizing The Deformation History Of The Southern Mina Deflection: Field And Structural Studies In The Huntoon Mountains, California-Nevada, Joseph Bodie Mccosby Jan 2019

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 …


Holocene Periods Of Aggradation And Incision, Hanson Creek, Washington, Levi Earl Windingstad Jan 2019

Holocene Periods Of Aggradation And Incision, Hanson Creek, Washington, Levi Earl Windingstad

All Master's Theses

The causes and timing of cycles of aggradation and incision in the Hanson Creek drainage in central Washington provide insight into changes in channel morphology and paleoenvironment within the region over the last 8000 years. Stratigraphically and spatially coincident archaeological evidence reveals information related to human occupation during the latter half of the epoch. Using LiDAR imagery and field surveys, recent processes such as degree of modern channel incision, accumulation of valley floor sediment, channel morphology and gradient were evaluated. The spatial distribution of these channel characteristics was assessed in relation to proximal landforms such as colluvial deposits, basalt outcrops, …


Late Devonian Sedimentary Record Of Appalachian Tectonics And Erosion: Geochronology And Geochemistry Of Detrital Muscovite And Zircon From Central Pennsylvania Strata, Cole T. Gardner Jan 2019

Late Devonian Sedimentary Record Of Appalachian Tectonics And Erosion: Geochronology And Geochemistry Of Detrital Muscovite And Zircon From Central Pennsylvania Strata, Cole T. Gardner

Honors Theses

Foreland basin sediment deposition in North-Central Pennsylvania during Late Devonian time records erosion of hinterland source terranes exhumed during regional plate convergence, including the collisional Acadian orogeny. The Catskill clastic wedge preserves a coarsening-upwards stratigraphic succession from marine to fluvial environments associated with sediment progradation and sea-level regression, yet depositional timescales and quantitative provenance data are largely unconstrained.

Detailed facies analysis of eight outcrops spanning >2 km of stratigraphy in Lycoming Co., Pennsylvania documents distinct upsection changes, interpreted to reflect changes in depositional environments consistent with previous sedimentology of the Catskill clastic wedge. Stratigraphy displays a transition from nearshore marine …


Structural Evolution Of The Eastern Anatolian Basins: An Example From Collisional To Postcollisional Tectonic Processes, Turkey, Ali̇ Yilmaz, Hüseyi̇n Yilmaz Jan 2019

Structural Evolution Of The Eastern Anatolian Basins: An Example From Collisional To Postcollisional Tectonic Processes, Turkey, Ali̇ Yilmaz, Hüseyi̇n Yilmaz

Turkish Journal of Earth Sciences

The Eastern Anatolian Basins (EABs) started to develop on a mosaic, made up of forearc deposits of the Eastern Pontide Arc (EPA), continental metamorphic rocks of the Anatolian-Iranian Platform (AIP), and obducted ophiolitic units of the North Anatolian Ophiolitic Belt (NAOB) and Southeastern Anatolian Ophiolitic Belt (SAOB). The basement rocks of the East Anatolian Region represent a continental fragment positioned between the EPA to the north and the Arabian Platform to the south. In appearance, it can be said that there are many different basins in the Eastern Anatolian Region. This paper reports on three of them that were studied …