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Sedimentological Properties And Depositional Environments Of The Holocene Sequence In Yenikapı, İstanbul, Meltem Sezerer Bulut, M.Namık Yalçin, Oya Algan

Bulletin of the Mineral Research and Exploration

During the salvage excavations in the area of the former Theodosian harbor in Yenikapı-İstanbul several ship wrecks from the Byzantine period, archaeological objects from different periods and a Holocene aged sedimentary sequence have been uncovered. In this study the lithological, lithostratigraphical and facies properties of the Holocene sequence are investigated in detail and its depositional environment is determined. For this purpose along four profiles (S1, S2, S3, S4) 14 different sections of a total thickness of 17.75 m are studied and 100 samples are collected. The grain size distribution of the samples is defined by sieve and sedigraph analysis and …

Holocene And Last Interglacial Climate Of The Faroe Islands From Sedimentary Plant Wax Hydrogen And Carbon Isotopes, Lorelei Curtin, William J. D'Andrea, Nicholas Balascio, Genevieve Pugsley, Gregory De Wet, Raymond Bradley

Geosciences: Faculty Publications

The Last Interglacial period (LIG) is Earth's most recent globally warm period and is analogous in some ways to projected future global warming. However, questions remain regarding the state of the climate during the LIG in the North Atlantic, a region that is extremely sensitive to changes in oceanic and atmospheric circulation. Here, we present hydrogen and carbon isotope (δD and δ13C) records from a suite of plant wax biomarkers preserved in Holocene and LIG lacustrine sediments from the North Atlantic Faroe Islands and interpret them as qualitative proxies for temperature and hydroclimate variability. These data are used to directly …

Pacific Southwest United States Holocene Droughts And Pluvials Inferred From Sediment Δ18o (Calcite) And Grain Size Data (Lake Elsinore, California), Matthew E.C. Kirby, William Paul Patterson, Matthew Lachniet, James A. Noblet, Michael A. Anderson, Kevin Nichols, Judith Avila

Geoscience Faculty Research

Records of past climate can inform us on the natural range and mechanisms of climate change. In the arid Pacific southwestern United States (PSW), which includes southern California, there exist a variety of Holocene records that can be used to infer past winter conditions (moisture and/or temperature). Holocene records of summer climate, however, are rare from the PSW. In the future, climate changes due to anthropogenic forcing are expected to increase the severity of drought in the already water stressed PSW. Hot droughts are of considerable concern as summer temperatures rise. As a result, understanding how summer conditions changed in …

The Influence Of Fetch On The Holocene Thermal Structure Of Hidden Lake, Glacier National Park, Jeffery R. Stone, Jasmine E. Saros, Trisha L. Spanbauer

Department of Earth and Atmospheric Sciences: Faculty Publications

We use three-dimensional modeling of the basin of Hidden Lake, Montana, to assess the influence of effective fetch on diatom-inferred changes in mixing depths throughout the Holocene. The basin of Hidden Lake is characterized by a complex morphometry; for example, three-dimensional modeling of the lake basin indicates that a decrease in lake level of 2 m would result in complete isolation of the deepest part of the lake basin from the rest of the lake. Our model suggests that small changes in the lake surface elevation at Hidden Lake would produce threshold-like responses in effective fetch, which in turn would …

Diatom-Inferred Records Of Paleolimnological Variability And Continental Hydrothermal Activity In Yellowstone National Park, Usa, Sabrina Brown

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Fossil diatoms were used to reconstruct paleoclimatic and hydrothermal conditions in Yellowstone National Park. First, an extensive literature review summarizes the current state of knowledge about eukaryotic organisms characteristic of continental hydrothermal environments. Eukaryotes in hydrothermal systems can live at extremes of acidity (pH 9.0), and at moderately high temperatures (<62 >^○C). Silicate and carbonate precipitation in continental hydrothermal environments is mediated by eukaryotic organisms, which are important members of biofilm communities.

A case study of alkaline-chloride sinter deposits in Yellowstone Lake and the Upper Geyser Basin inferred in-situ diatom growth rather than post-depositional accumulation of valves settling from …

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 …

New Source-To-Sink Approach In An Arctic Catchment Based On Hyperspectral Core-Logging (Lake Linné, Svalbard), Antonin Van Exem, Maxime Debret, Yoann Copard, Charles Verpoorter, Gregory De Wet, Nicolas Lecoq, Philippe Sorrel, Alan Werner, Steven Roof, Benoit Laignel, Michael Retelle

Geosciences: Faculty Publications

No abstract provided.

Peatlands And Histosols In Canaan Valley National Wildlife Refuge, West Virginia, Mitzy Leigh Schaney

Graduate Theses, Dissertations, and Problem Reports

Canaan Valley in West Virginia contains a greater area of peatlands than any other locality in the mid-Atlantic Highlands. Extensive fieldwork focused on peat stratigraphy and pedology, combined with high-resolution radiocarbon dating, was used to evaluate five peatlands within Canaan Valley National Wildlife Refuge (CVNWR) in the central Appalachian Mountains. One hundred soil cores were profiled and described, 30 with laboratory data, including 52 radiocarbon dates. Calibrated basal peat dates among the five mapped peatlands indicate a late Pleistocene timeframe for the onset of peat genesis, ranging from ~18,600 to ~15,200 cal yr BP. The dates for peat initiation are …

Vegetation Sensitivity During The Mid-Holocene Warming In Western Ohio, Kristin Kopera

Browse all Theses and Dissertations

There has been a growing interest in prairie reconstruction in western Ohio, yet there are few recent academic sources supporting the claim that prairies appeared in western Ohio during the mid-Holocene. The hypsithermal was the warmest and driest part of the Holocene and occurred from 8,000-4,000 years ago in the Midwest. During the hypsithermal, the Prairie Peninsula appeared from Minnesota to eastern Ohio. If prairie did appear in Ohio, it occurred during the mid-Holocene hypsithermal. The goal of this study was to determine if western Ohio experienced a prairie period during the hypsithermal using pollen as a proxy for past …

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 …