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Showing 1 to 16 of 16 for “"Impact Crater"”.
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Thermal History of the Chesapeake Bay Impact Crater
… high groundwater salinities exist within the syn-impact sediment of the Chesapeake Bay impact crater, including an unexplained brine. This brine may be the result of phase-separation of seawater that occurred within the syn-impact sediments as underlying deformed and possibly melted basement rock …
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Structure of the Chesapeake Bay Impact Crater from Wide-Angle Seismic Waveform Tomography
The Chesapeake Bay impact structure is one of the largest and most well preserved impact structures on Earth. It has a unique morphology composed of an inner crater penetrating crystalline basement surrounded by a wider crater in the overlying sediments. In 2004, the U.S. Geological Survey …
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3D GROUND-PENETRATING RADAR (GPR) INVESTIGATIONS: BURIED CULVERTS, HISTORICAL GRAVES, A SANDSTONE RESERVOIR ANALOG, AND AN IMPACT CRATER
… historical graves, reservoir analogs, and impact craters. In the first case of “buried culverts” I evaluated the GPR performance across five antenna frequencies to determine which would best image buried culverts. Laboratory measurements of soil were made to provide independent measurements …
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A multi-proxy study of the Kalkkop impact Crater Lake deposits in south-central South Africa: implications for late neogene climate evolution
The Kalkkop Crater Lake deposit formed as a result of a meteorite impact, and is situated ~51 km southwest of Graaff-Reinet in the Southern part of South Africa. The structure is about 650 m wide, and contains 90 m of lake deposits that are mainly carbonate precipitates. A 90 m sediment core from …
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Carbon Chemistry Of Giant Impacts
Impact diamonds were found in several impactites from the Ries crater, Germany including fallout and fallback (crater fill) suevites. a glass bomb, impact melt rock and shocked gneiss. These diamonds formed two distinct grain size populations: 50-300µm apographitic. platy aggregates with surface …
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Geologic Setting of the Phoenix Lander Mission Landing Site
… by the ~0.6 Ga, 11.5 km wide, bowl-shaped impact crater, Heimdal, and its areally extensive ejecta deposits. The Lander is located ~20 km to the west of the crater and is sitting on a plains surface underlain by partially eroded Heimdal ejecta deposits. Heimdal was produced by a …
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Assessing the Crustal Source Depth and Cause of Magnetization North of Caloris Planitia, Mercury
… features were formed in the ejecta blankets of impactors. According to this hypothesis, the impactor material would mix with the crustal material, settle as the ejecta blanket, cool, and then become magnetized in an active core magnetic field. As Mercury's crust typically contains a low amount …
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Reassessing the Holleford impact structure: Applying modern techniques to a classic Canadian crater
Impact cratering is a ubiquitous geological process affecting all planetary bodies with a solid surface. Despite advances in impact crater classification and confirmation, there still exists a disparity in impact evidence quality and type for newly confirmed versus previously established sites. …
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Modern Pollen-Vegetation Relationships In Ghana, Tropical West Africa
… Ghana, is a 1 million year old meteorite impact crater-lake, in which pollen has been deposited tracking vegetation change, including the expansion and contraction of grass dominated landscapes evidenced by very high proportions of Poaceae pollen. This thesis explores the modern …
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Multiple Glaciations on Mars?
… Euripus Mons, a mountain east of the Hellas impact crater (45°S 105°E). The motivation behind this project was to determine if this ice, held within the Euripus Mons LDA, ever advanced beyond the current observed boundaries. Additionally, if the ice did advance was it a singular event, or, …
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Finite-element modeling of large impact craters: Implications for the size of the Vredefort structure and the formation of multiple ring craters
Impact cratering is a complex process which is not yet fully understood, especially in the cases of large planetary events. Most of the observations of impact craters created by such events are limited to remote sensing of their surface morphology; although there are large terrestrial craters whose …
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Description and Genesis of the Western Cold Turkey Creek Field Anomaly, Williston Basin, Bowman County, North Dakota
… identified by oil explorationists as a possible impact crater, but its origin remained uncertain. The purpose of this study is to attempt to ascertain if sufficient evidence exists to determine that the anomaly is of impact origin.</p><p>The study area was confined to a nine township area …
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The influence of cylindrical charge geometry on the velocity of blast-driven projectiles in one dimension
The impact of improvised explosive devices (IEDs) on the safety of civilians can be devastating, especially when solid objects are inserted into the explosives. These inserts are propelled at high speed and increase the lethality of an IED detonation. Due to the wide range of possible IED …
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Using Crustal Thickness Modeling to study Mars' Crustal and Mantle Structures
… in the misfit maps resembles a regional-scale impact crater that may have created the Borealis Basin in the Northern Lowlands, also consistent with current hypotheses about the formation of the Northern Lowlands. A result of Airy isostacy (with only the linear terms in topography) is that the …
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Lacustrine Turbidites from Tropical African Lakes as Indicators of Hydrologic and Climatic Changes
… and carbon isotopes, from the Lake Bosumtwi impact crater. Peak turbidite sedimentation is found to correlate with intervals of high TOC and markedly negative d13C values, suggesting that the turbidites were deposited during periods of high lake-levels. The multi-proxy paleohydrologic record …
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Fault formation in porous sedimentary rocks at high strain rates
… the porous Navajo Sandstone at the Upheaval Dome impact structure in Canyonlands National Park, southeast Utah, where high strain rate conditions are known to have occurred. We found no evidence for DBDZ formation along the fault planes at Upheaval Dome. Instead pulverized quartz grains within the …