Over 1150 m of middle to late Eocene nonmarine arkose, lithic arkose, mudstone, and siltstone, referred to here as the Chambers Creek beds, are int~r.stratified with, and overlain by over 1600 m of late Eocene-Oligocsne(?) andesitic volcaniclastic and subordinate volcanic rocks assigned to the Ohanapecosh Formation, in a dissected structural high in the southern Washington Cascade Range, about 18 km south-southeast of the town of Packwood.

Studies of episodic shoreline accretion of the Columbia River Littoral Cell (CRLC) have been ongoing since 1964. In this study, the sediment volumes in the late Holocene barriers and beach plains are compiled and formatted in GIS compatible databases for the four sub-cells of the CRLC. Initial evaluation involved the creation of a geodatabase of 160 dated retreat scarp positions, that were identified on across-shore GPR and borehole profiles. Ten primary timelines were identified throughout the CRLC (0-4700 ybp) and those were used to develop polygon cells. Elevation, distance measurements, and position information were all linked to the polygon through a centroid location within the geodatabase. Once the geodatabase was completed, data was imported into MSAccessTM to create a relational database that would allow for examination of the littoral cell in its entirety or of the individual sub-cells. Within the database, sediment volumes, ages, accretion rates, sediment thicknesses, and timeline relationships were calculated and recorded. Using the database, the accretion history of the Columbia River Littoral Cell was evaluated and this examination illustrated the complexity of the system. Northern littoral transport was shown to be an important factor in the development of the littoral cell as a whole. Total sediment volume in the littoral cell was calculated to be 1.74 x 109 m3, with a mean accretion rate of 1.90 x 104 m3/yr, which is significantly less than some previous studies. This is due to a more detailed analysis of the beach and foredune facies themselves. This is likely the result of the higher precision of beach and foredune surface information using LiDAR. The database shows that the developmental history of the CRLC is dependent on temporal and spatial constraints that can be coupled with reverse modeling to predict shoreline erosion trends from impounded river sediments and potential global sea level rise. The North Beaches and Grayland Plains sub-cells have the greatest potential for future erosion; followed by the Clatsop Plains sub-cell.

No description available.

The Desmoinesian Marmaton Group, along the southern portion of the Anadarko Basin in the Granite Wash, comprises over 2,000 feet of stacked tight sandstones and conglomerates, containing unconventional reservoirs. Uncertainty around facies variability and lateral continuity of these reservoirs represents challenges to accurate reservoir characterization due to laterally restricted submarine fan systems, and mountainront faulting. This study examines 206 wire-line well-log suites and nine ice-house flooding surfaces across an 810-square mile study area to frame fine-scale sequences, track facies changes, and estimate fault timing and duration. This high-resolution stratigraphic framework comprises a hierarchy of cycles: one third-order, three fourth-order, and eight fifth-order cycles; these were mapped across fault blocks. Mapping at the fifth-order scale documented previously un-published faults, and showed that movement occurred during two separate fifth-order cycles. Within the stratigraphic framework, well log trends, calibrated to core descriptions, enabled prediction of depositional environments in uncored wells.

The Bahamas Island archipelago grows by the precipitation and secretion of calcium carbonate. A majority of this growth is by lateral accretion of shoreline sedimentary deposits. Previous research is not clear on whether the growth is largely due to eustasy, sediment input from catastrophic events, or a combination of both. The Bahamas is an ideal location for studying Holocene carbonate generation and deposition, but there is limited research on the analysis of strandlines in relation to lateral accretion. Carbonate strandline deposits are commonly classified as low-energy beach ridge deposits. Previous researchers have primarily focused on ooid shoals and subtidal regions. Understanding the mechanisms of platform and shoreline growth in the Bahamas is important for creating petroleum reservoir analogs for exploration. We use ground penetrating radar (GPR) to image and interpret the internal fine-scale stratigraphy of Bahamian carbonate strand plains and thereby constrain our understanding of the processes by which the islands grow. Although GPR has been used extensively to analyze the interior of clastic strandline deposits across the world, tropical carbonate settings have received little attention. We are the first to utilize GPR to study strand plains in Crooked Islands, The Bahamas, our primary location for 2D GPR data acquisition. We integrate our interpretation of these data with a 3D GPR data volume collected on Pleistocene eolianites on San Salvador Island, The Bahamas. We used a GSSI (Geophysical Survey Systems, Inc.) bistatic 400-MHz antenna with a field frequency filter of 100"“800 MHz for all datasets. GPR allowed visualization of the interior of the strand plains down to a depth of about 2 m with high resolution. Data processing was performed using state-of-the-art petroleum industry techniques (e.g., gain control, deconvolution, migration, seismic attribute computation) to better visualize the reflectivity. Our data constrains a model that the lateral accretion of carbonate sediment preserved in strandline was deposited in a combination of storm processes and gradual sediment progradation, rather than one or the other. Our conclusions help determine that The Bahamas is ideal for GPR imaging of strandlines due to being assessable, high data quality, no clastic influence, and a dry environment during parts of the world

Here we examine seasonal grain-size trends on 18 beaches in the Northeastern US and dispersed along the post-glacial coast of Massachusetts (USA) in order to explore the mechanisms influencing median grain size and slope. Over 800 grain size samples were collected along 200 summer and winter cross-shore beach elevation surveys. Obtained grain size and beach slope data are compared to coastal morphology, sediment source, wave height, and tidal magnitude in order to ascertain controls on beach characteristics. In general, median grain size increases with intertidal beach slope in the study region. However, grain sizes along post-glaciated beaches in the study are as much as an order of magnitude coarser for the same beach slopes when compared to beaches for other regions of the US. Grain size and slope for beaches in the northeastern US also exhibit less correlation with oceanographic processes (i.e. wave climate and tidal magnitude). Instead, grain size trends are primarily driven by the composition of nearby glacial deposits that serve as the primary source of sediment to beaches in the study region. Results provide quantitative support for the distribution and composition of legacy glacial deposits rather than oceanographic conditions serving as the predominant governor of beach grain size along post-glaciated coastlines of the Atlantic continental margin.

A tsunami generated by the C.E. 1707 Hōei earthquake is largely thought to be the flood event of record for southwestern Japan, yet historical documentation of the event is scarce. This is particularly true in northwestern Shikoku within the Bungo Channel, where significant inconsistencies exist between historical records and model-derived tsunami heights. To independently assess flooding from the C.E. 1707 Hōei tsunami in the context of the region’s long-term flooding history, we present complementary reconstructions of extreme coastal inundation from three back-barrier lakes in the northern Bungo Channel: Lake Ryuuoo, Lake Amida, and Lake Kamega. At all sites, the most prominent marine overwash deposit of the past ~1,000 years, as defined by grain size, density, and geochemical indicators, is consistent with the timing of the 1707 tsunami, providing strong evidence that the event caused the most significant flooding of the last millennium in this region. At Lake Ryuuoo, modern barrier beach elevations and grain sizes in the tsunami’s resultant deposit provide ~4 m as the first physically based height constraint for the 1707 tsunami in the northern Bungo Channel. Around 1,000 years ago, a concurrent and abrupt transition in lithology observed at all three sites is also consistent with rapid, regional geomorphic change. At Lake Ryuuoo, a marine overwash deposit comparable to the 1707 deposit directly overlies this transition. A 1,000-year-old lithological transition or deposit has not been observed at sites closer to the mouth of the Bungo Channel, suggesting that the deposit in Lake Ryuuoo is more consistent with a tsunami generated by local seismicity along the Japan Median Tectonic Line than with a Nankai Trough-derived tsunami. Our findings are significant in that they provide three new millennial-scale tsunami inundation reconstructions for a relatively understudied region of Japan, along with the first physically based height constraint for the Hōei tsunami in the northern Bungo Channel.

Stratigraphic successions of sedimentary rocks represent an important repository for signals pertaining to the history and evolution of Earth. Whereas the specific processes reflected by the stratigraphic record differ with respect to a given depositional environment, deposits in deep-marine settings, particularly passive margins, provide a unique, long-term record of paleoclimate, paleoceanography, and tectonics affecting the basin in question. Whereas deep-marine strata may be used to answer myriad of questions regarding the evolution and development of Earth systems, this dissertation narrowly targets two distinct aspects of sedimentation in deep-sea settings. The first two chapters focus on the utility of sortable silt in reconstructing bottom-current intensity linked to major shifts in climate. First, the relationship of sortable silt to flow velocity was tested under controlled conditions in a flow-through flume. This chapter investigates the correlation of sortable silt metrics across several experimental parameters, which is found here to dispute longstanding assumptions that multiple metrics must correlate to infer sediment sorting by deep currents. Additionally, the results are compared to calibrations from natural settings, where the correlation between the two datasets is remarkably similar, validating the relationship of sortable silt with current velocity in the deep ocean. Chapter two leverages sortable silt to investigate the long-term evolution of the Deep Western Boundary Current in the North Atlantic, targeting contourite drifts offshore Newfoundland to investigate the Eocene-Oligocene Transition (EOT), the most recent global greenhouse-to-icehouse transition. Results suggest that the Deep Western Boundary Current intensified gradually from 35-26 Ma, not abruptly at the EOT, and change consistent with deepening of the Greenland-Scotland Ridge and enhanced overflow of deep water into the North Atlantic. Chapter three utilizes detrital zircon U-Pb dating to characterize source-to-sink pathways and linkages during the rift-to-drift transition, in the Early Cretaceous, along the U.S. mid-Atlantic passive margin. This work shows that onshore and offshore system segments were initially disconnected, and progressively integrated over the course of ~45 Myr. Taken together, this work demonstrates a focused yet powerful example of how deep-marine sedimentary systems can be leveraged to robustly model major changes throughout Earth history. / Doctor of Philosophy / Sediments and sedimentary rocks deposited in the deep ocean house long-term signals pertaining to important Earth processes and properties. The nature of a given deposit, for example, can be the direct result of climatic conditions or tectonic development in adjacent mountainous and coastal environments. While the range of questions that can be answered using the sedimentary record is vast, this dissertation narrowly focuses on 1) how deep-ocean currents change over long periods of time, and 2) how onshore and offshore depositional environments correlate during the early phases of supercontinent break-up. To address the reconstruction of deep-ocean currents, laboratory experiments were performed to test how the sortable silt proxy – the 10-63 um fraction of a deposit – correlates with current velocity, the first controlled test of the proxy since its inception by paleoceanographers nearly three decades ago. Sortable silt is then applied to sediments of Eocene-Oligocene age, recovered from contourites offshore Newfoundland, Canada, to assess the long-term behavior of the Deep Western Boundary Current in the North Atlantic across the Eocene-Oligocene Transition (EOT). While the EOT, a major global cooling that occurred ~33.7 Ma, is well-studied with respect to Antarctica and its surrounding ocean basins, little is known about the paleoceanographic response of the North Atlantic. Grain-size records show a gradual increase in sortable silt before, during, and after the EOT, through entirety of the 9 Myr record. This trend is interpreted to reflect a long-term invigoration of the Deep Western Boundary Current in North Atlantic, likely due to progressive deepening of the Greenland-Scotland Ridge. The final chapter leverages detrital zircon U-Pb geochronology to compare sediment provenance of Early Cretaceous fluvial sandstones with coeval, distal turbidite sands. Results suggest that coastal rivers were fed by a single source terrane during the earliest Cretaceous, disconnected from the regional catchment feeding the submarine fan. By the Aptian-Albian, coastal rivers share a detrital zircon signature with turbidite strata, suggesting that rivers were progressively integrated into the sediment-routing system feeding the offshore margin.

Here we investigate sedimentological responses to past climate change in shallow to deep marine depositional environments. Our primary study spans from the Late Pliocene to the Pleistocene (3.3 to 0.7 Ma), and features results from two International Ocean Discovery Program (IODP) Sites U1525 and U1524. Each of these sites is discussed in separate chapters here (Chapters 1 and 2). This interval experienced the change from the warming of the Late Pliocene, known as the Mid-Piacenzian Warming Period, to the Pleistocene cooling. This shift significantly impacted the expansion of the West Antarctic Ice Sheet, sea ice/polynya formation, and, notably, the genesis of Antarctic Bottom Water (AABW), a crucial component of the global thermohaline circulation. In Chapter 1, we propose that turbidite currents, arising from the formation of dense shelf water (DSW) in the Ross Sea (a precursor to AABW), leave a distinct record in the levees of Hillary Canyon. This canyon acts as a conduit, channeling DSW into the deep ocean and contributing to AABW production. By analyzing turbidite beds based on their frequency, thickness, and grain size, we gain insights into the historical occurrence and magnitude of these currents. Furthermore, we explore the influence of factors such as shelf availability and sea ice/polynya formation within the broader climate context of AABW formation. Chapter 2 shifts its focus to the sedimentological variability from shelf-to-slope along Hillary Canyon. This chapter examines the turbidite record associated with AABW formation within the shared timeframe (2.1 to 0.7 million years ago) between IODP Sites U1524 and U1525, and the impact of along slope currents and other processes in the sedimentary deposition and transport. The second study interval (Chapter 3), focuses on the regional sedimentological response proximal to a hydrothermal vent complex associated with the Paleocene-Eocene Thermal Maximum (PETM; ca. 56 Ma), a global warming event during which thousands of Gt C was released into the ocean-atmosphere on Kyr timescales. IODP Site U1568, strategically located near the hydrothermal vent complex and part of a broader drilling transect in the Modgunn Arch, North Atlantic, is the main study subject. This site's proximity to the vent complex offers a distinctive environment for refining our understanding of stratigraphy and sedimentology within the PETM. We achieve this through a comprehensive analysis of grain size and composition, coupled with a comparison to XRF data. Our findings show that the timing between the onset of the PETM and the response of the sedimentary system to the warming, reflected in the grain size coarsening after the start of the PETM, is not synchronous. Notably, the transition from a marine to a more terrestrial composition predates this shift in grain size, aligning with the PETM onset instead. / Doctor of Philosophy / Deep-marine core records are invaluable sources of sedimentological information that provide insights into the ocean's response to past climates. These cores, extracted from the deep-ocean floor, contain layers of sediment that accumulate over time because of the different processes that occur in the ocean. Analyzing these sediments, by looking at their physical characteristics like how frequently are they deposited, the thickness of the layers, their grain size, and their composition helps to reconstruct past environmental conditions and understand how the oceans have responded to climatic changes. This dissertation focuses on studying the record of two main processes. The first one is the sedimentary record left behind by the formation of Antarctic Bottom Water (AABW), one of the coldest (-1°C), deepest (> 2000 meters below sea level), and densest water masses in the ocean. AABW is a key component of the global ocean circulation system, often referred to as the "global conveyor belt" or the thermohaline circulation. This circulation pattern plays a crucial role in redistributing heat, salt, and nutrients around the world's oceans. AABW is formed near Antarctica through a process that begins with the cooling and sinking of surface waters near the continent. As these waters sink, they become denser and eventually form AABW, filling the deep ocean basins around Antarctica. The dense water flows from the surface to the bottom of the ocean forming turbidity currents. These turbidity currents, dense plumes of water and sediments, flow down submarine conduits, such as Hillary Canyon in the Ross Sea, Antarctica, leaving a sedimentary record in the levees or flanks, called turbidites. The turbidite sequences in sediment cores can reveal information about the frequency and magnitude of these currents, providing insights into the sediment transport processes in deep-marine settings, and for this work, the history of the AABW formation over the last 3.3 Ma. This study will help to understand what are the main controls for AABW formation across different climates in the past, and how we project this into the future climate scenarios. In the second part of the study (Chapter 3), we look at the sedimentary record of a warming event that happened around 56 million years ago. This event, known as the Paleocene-Eocene Thermal Maximum (PETM), involved a significant amount of carbon being released into the air and oceans over thousands of years (150,000 to 200,000). Our focus is IODP Site U1568, located near a submarine hydrothermal vent, and part of a larger drilling transect in the North Atlantic's Modgunn Arch. The vent's unique location provides a crucial perspective for understanding how the system responded to the warming during the Paleocene-Eocene Thermal Maximum (PETM). This warming event was triggered by the release of carbon into the atmosphere, with the vent serving as one of the conduits for this release. To understand this, we studied the grain size and content of the sediment, and compared that with XRF data. Changes in grain size serve as indicators of shifts in the energy of the environment – coarser grains signify a more energetic system. Warmer weather, for instance, can increase precipitation, leading to more erosion and sediment influx into the basin. This influx also brings in more materials from the land, as evidenced by the presence of microfossils and plant fragments. Our discoveries indicate that the sedimentary system responded gradually to the PETM, as reflected in the coarsening of grain size after the PETM's onset. Notably, the transition from a marine to a more terrestrial composition occurred before the change in grain size, aligning more closely with the initiation of the PETM itself.

The Lost River Groundwater Drainage Basin in Warren County, Kentucky, is a karst drainage system encompassing 55 square miles (143 square kilometers) developed within the Mississippian St. Louis and Ste. Genevieve Limestones. Near the contact between these two formations are two bedded chert units, the Lost River Chert Bed (Elrod, 1899) within the Ste. Genevieve and the Corydon Chert Member (Woodson, 1983) of the St. Louis, which appear to be perching layers to shallow karst groundwater flow. Groundwater may be seen flowing on top of these beds in various cave streams and at swallets and springs throughout the basin. In order to compare the vertical positions of these layers to shallow karst groundwater flow, geologic structure maps of the Lost River Chert Bed and the Corydon Chert Member were prepared for the basin, along with a contour map of the water table (at or near which shallow karst groundwater flow is assumed to take place) over the same area. These surfaces were digitized, then contoured and compared using SURFACE II and DISSPLA computer graphics systems. Correlation was accepted for points where the water table is either 20 feet (6.1 meters above or below the top of the two chert layers. The water table (at baseflow conditions) was found to correlate with the Lost River Chert Bed over 42.6% of the basin, as well as 40.7% for the Corydon Member. Shallow karst groundwater flow is found to correlated with bedded chert layers over 83.3% of the study area, and therefore it is concluded that chert layers have a dominant effect on the vertical position of groundwater flow within the Lost River Groundwater Drainage Basin.