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Jesse T Korus - One of the best experts on this subject based on the ideXlab platform.
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three dimensional architecture and hydrostratigraphy of cross cutting buried valleys using airborne electromagnetics glaciated Central Lowlands nebraska usa
Sedimentology, 2017Co-Authors: Jesse T Korus, Matt R Joeckel, Dana Divine, Jared D AbrahamAbstract:Buried valleys are characteristic features of glaciated landscapes and their deposits host important aquifers worldwide. Understanding the stratigraphic architecture of these deposits is essential for protecting groundwater and interpreting sedimentary processes in subglacial and ice-marginal environments. The relationships between depositional architecture, topography and hydrostratigraphy in dissected, pre-Illinoian till sheets is poorly understood. Boreholes alone are inadequate to characterize the complex geology of buried valleys, but airborne electromagnetic surveys have proven useful for this purpose. A key question is whether the sedimentary architecture of buried valleys can be interpreted from airborne electromagnetic profiles. This study employs airborne electromagnetic resistivity profiles to interpret the three-dimensional sedimentary architecture of cross-cutting buried valleys in a ca 400 km2 area along the western margin of Laurentide glaciation in North America. A progenitor bedrock valley is succeeded by at least five generations of tunnel valleys that become progressively younger northward. Tunnel valley infills are highly variable, reflecting under-filled and over-filled conditions. Under-filled tunnel valleys are expressed on the modern landscape and contain fine sediments that act as hydraulic barriers. Over-filled tunnel valleys are not recognized in the modern landscape, but where they are present they form hydraulic windows between deep aquifer units and the land surface. The interpretation of tunnel valley genesis herein provides evidence of the relationships between depositional processes and glacial landforms in a dissected, pre-Illinoian till sheet, and contributes to the understanding of the complex physical hydrology of glacial aquifers in general. This article is protected by copyright. All rights reserved.
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geologic field trips along the boundary between the Central Lowlands and great plains
GSW Books, 2014Co-Authors: Jesse T KorusAbstract:Geological and human forces have created some spectacular treasures at the boundary between the Central Lowlands and the Great Plains, and three of them are explored in this guide. In northern Nebraska, the Ashfall Fossil Beds site, a world-class Lagerstatte of articulated mammal, reptile, and bird skeletons, reveals the mass death of a Miocene biotic community. Chapter [1][1] provides a detailed overview of the geology, paleontology, and reconstructed paleocommunity at Ashfall. The bluffs of the Missouri River in eastern Iowa contain some classic type sections of Pleistocene stratigraphic units. Chapter [2][2] explores the historical development of Pleistocene stratigraphy in this area and presents new data to refine understanding of the area’s complex geological history. Finally, Chapter [3][3] presents a unique tour of the Nebraska State Capitol in Lincoln, which is clad with Indiana limestone and adorned with igneous, metamorphic, and sedimentary rocks from European and U.S. quarries. The field guide describes the historical, architectural, and geological aspects of these stones. [1]: /gswbk/9780813756363/9780813756363/SEC1.atom [2]: /gswbk/9780813756363/9780813756363/SEC2.atom [3]: /gswbk/9780813756363/9780813756363/SEC3.atom
Eileen Johnson - One of the best experts on this subject based on the ideXlab platform.
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late quaternary landscape evolution soil stratigraphy and geoarchaeology of the caprock canyonlands northwest texas usa
Quaternary International, 2014Co-Authors: Laura R Murphy, Stance Hurst, Vance T Holliday, Eileen JohnsonAbstract:Abstract In northwest Texas, USA, between the Southern High Plains to the west and the Central Lowlands to the east, lies a geographic boundary known as the “Escarpment Breaks” or “Caprock Canyonlands.” The canyonlands contain abundant springs, lithic resources, shelter, and plant and animal food sources that attracted hunter-gatherer groups. A geoarchaeological study was conducted in the canyonlands to determine the effects of late-Quaternary landscape evolution, especially intensive erosion, on the region's archaeological record. Geomorphic and stratigraphic field research and a total of 95 new radiocarbon age determinations, 94 of which were determined on paired samples, aid in reconstructing an understudied dynamic and erosive landscape, and explain how the landscape has changed. The pattern is similar to reported data from the Central Plains and western Rolling Plains but dissimilar to the Southern High Plains. High rates of erosion and geological controls on the South Fork of the Double Mountain Fork of the Brazos River, a 4th order stream, have hindered the discovery of deeply buried soils and in situ Paleoindian artifacts and features, but a late-Holocene pedocomplex is relatively intact in valley fills beneath remnants of the T-2 terrace of the South Fork. The eroding slopes near the edge of the caprock escarpment exposed a record of in situ Archaic to Protohistoric-aged materials. The eroding slopes should be targeted for future quantification of erosion and archaeological preservation bias for the canyonlands.
Jared D Abraham - One of the best experts on this subject based on the ideXlab platform.
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three dimensional architecture and hydrostratigraphy of cross cutting buried valleys using airborne electromagnetics glaciated Central Lowlands nebraska usa
Sedimentology, 2017Co-Authors: Jesse T Korus, Matt R Joeckel, Dana Divine, Jared D AbrahamAbstract:Buried valleys are characteristic features of glaciated landscapes and their deposits host important aquifers worldwide. Understanding the stratigraphic architecture of these deposits is essential for protecting groundwater and interpreting sedimentary processes in subglacial and ice-marginal environments. The relationships between depositional architecture, topography and hydrostratigraphy in dissected, pre-Illinoian till sheets is poorly understood. Boreholes alone are inadequate to characterize the complex geology of buried valleys, but airborne electromagnetic surveys have proven useful for this purpose. A key question is whether the sedimentary architecture of buried valleys can be interpreted from airborne electromagnetic profiles. This study employs airborne electromagnetic resistivity profiles to interpret the three-dimensional sedimentary architecture of cross-cutting buried valleys in a ca 400 km2 area along the western margin of Laurentide glaciation in North America. A progenitor bedrock valley is succeeded by at least five generations of tunnel valleys that become progressively younger northward. Tunnel valley infills are highly variable, reflecting under-filled and over-filled conditions. Under-filled tunnel valleys are expressed on the modern landscape and contain fine sediments that act as hydraulic barriers. Over-filled tunnel valleys are not recognized in the modern landscape, but where they are present they form hydraulic windows between deep aquifer units and the land surface. The interpretation of tunnel valley genesis herein provides evidence of the relationships between depositional processes and glacial landforms in a dissected, pre-Illinoian till sheet, and contributes to the understanding of the complex physical hydrology of glacial aquifers in general. This article is protected by copyright. All rights reserved.
Daniele Questiaux - One of the best experts on this subject based on the ideXlab platform.
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the Central Lowlands of the hunter valley nsw why so few early sites have been found in this archaeologically rich landscape
Australian Archaeology, 2014Co-Authors: Philip Hughes, Nigel A Spooner, Daniele QuestiauxAbstract:The Central Lowlands of the Hunter Valley are rich in Holocene-aged open stone artefact concentrations but, to date, very few verified traces of Pleistocene occupation have been found there. The Central Lowlands would have been a reasonably attractive place to live, so logic suggests that there should be Pleistocene sites. Given the geomorphic and soil formation processes that have operated over the potentially long period of Aboriginal occupation of the Central Lowlands, however, it is likely that most archaeological materials older than ca 10,000 years have been either completely removed or widely dispersed across the landscape and are no longer recognisable as discrete Pleistocene-aged assemblages. Sand bodies have the greatest potential to contain older sites, but in most, if not all, cases their stratigraphic integrity has been compromised, principally by bioturbation. Understanding the landscape history over the last 90,000 years is the key to understanding why finding Pleistocene sites in t...
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the Central Lowlands of the hunter valley nsw why so few early sites have been found in this archaeologically rich landscape
Australian Archaeology, 2014Co-Authors: Philip Hughes, Nigel A Spooner, Daniele QuestiauxAbstract:The Central Lowlands of the Hunter Valley are rich in Holocene-aged open stone artefact concentrations but, to date, very few verified traces of Pleistocene occupation have been found there. The Central Lowlands would have been a reasonably attractive place to live, so logic suggests that there should be Pleistocene sites. Given the geomorphic and soil formation processes that have operated over the potentially long period of Aboriginal occupation of the Central Lowlands, however, it is likely that most archaeological materials older than ca 10,000 years have been either completely removed or widely dispersed across the landscape and are no longer recognisable as discrete Pleistocene-aged assemblages. Sand bodies have the greatest potential to contain older sites, but in most, if not all, cases their stratigraphic integrity has been compromised, principally by bioturbation. Understanding the landscape history over the last 90,000 years is the key to understanding why finding Pleistocene sites in the Hunter Valley has proven to be so difficult. Geoarchaeological evidence which illustrates this difficulty is presented from sites in three deposits of probable Pleistocene to early Holocene age - two in sand bodies and one in colluvium. On one sand body (the Warkworth sand sheet) there is contestable evidence for traces of pre-LGM occupation beginning more than 23,000, possibly 50,000, years ago, but on the other (the Cheshunt dune) there is no evidence of occupation beyond the mid-Holocene.
Matt R Joeckel - One of the best experts on this subject based on the ideXlab platform.
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three dimensional architecture and hydrostratigraphy of cross cutting buried valleys using airborne electromagnetics glaciated Central Lowlands nebraska usa
Sedimentology, 2017Co-Authors: Jesse T Korus, Matt R Joeckel, Dana Divine, Jared D AbrahamAbstract:Buried valleys are characteristic features of glaciated landscapes and their deposits host important aquifers worldwide. Understanding the stratigraphic architecture of these deposits is essential for protecting groundwater and interpreting sedimentary processes in subglacial and ice-marginal environments. The relationships between depositional architecture, topography and hydrostratigraphy in dissected, pre-Illinoian till sheets is poorly understood. Boreholes alone are inadequate to characterize the complex geology of buried valleys, but airborne electromagnetic surveys have proven useful for this purpose. A key question is whether the sedimentary architecture of buried valleys can be interpreted from airborne electromagnetic profiles. This study employs airborne electromagnetic resistivity profiles to interpret the three-dimensional sedimentary architecture of cross-cutting buried valleys in a ca 400 km2 area along the western margin of Laurentide glaciation in North America. A progenitor bedrock valley is succeeded by at least five generations of tunnel valleys that become progressively younger northward. Tunnel valley infills are highly variable, reflecting under-filled and over-filled conditions. Under-filled tunnel valleys are expressed on the modern landscape and contain fine sediments that act as hydraulic barriers. Over-filled tunnel valleys are not recognized in the modern landscape, but where they are present they form hydraulic windows between deep aquifer units and the land surface. The interpretation of tunnel valley genesis herein provides evidence of the relationships between depositional processes and glacial landforms in a dissected, pre-Illinoian till sheet, and contributes to the understanding of the complex physical hydrology of glacial aquifers in general. This article is protected by copyright. All rights reserved.