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Full-Text Articles in Physical Sciences and Mathematics
Hargraves Crater Ejecta And Implications For Impact Processes, Leah E. Sacks
Hargraves Crater Ejecta And Implications For Impact Processes, Leah E. Sacks
Electronic Thesis and Dissertation Repository
Impact craters and their ejecta deposits offer insights into the structure and composition of planet crusts. Hargraves Crater, Mars, demonstrates an unusual balance of exposure and preservation in its ejecta. Analysing its morphologic, morphometric, thermophysical, and stratigraphic characteristics, we interpret two predominant units: an underlying ballistic lithic breccia and an overlying impact melt-bearing deposit. The lower unit is a lithic breccia composed of sub-angular, unsorted clasts (~10-12 m mean diameter), while the overlying unit is a smooth, dark toned, smaller clast-bearing (~1 m diameter at image resolution) impact melt-bearing unit with polygonal fracturing. There appears to be a sharp contact …
Impact Melt-Bearing Deposits Around Martian Craters, William A. Yingling
Impact Melt-Bearing Deposits Around Martian Craters, William A. Yingling
Electronic Thesis and Dissertation Repository
In this work, we investigate impact melt emplacement around Martian craters. We compare our results to melt emplacement processes found on Venus, the Moon, and Mercury. We tentatively find Martian melt emplacement more closely resembles Venusian emplacement, rather than lunar emplacement. This suggests Martian melt emplacement likely takes place during the excavation stage where impactor momentum is imparted to the melt. Mercury and Mars have amongst the highest and lowest average impact velocities, respectively, of terrestrial bodies in the Solar System, but a significant difference in emplacement is not observed. This suggests impact velocity may not have as large an …
Characterization Of Impactite Clay Minerals With Implications For Mars Geologic Context And Mars Sample Return, Christy M. Caudill
Characterization Of Impactite Clay Minerals With Implications For Mars Geologic Context And Mars Sample Return, Christy M. Caudill
Electronic Thesis and Dissertation Repository
Geological processes, including impact cratering, are fundamental throughout rocky bodies in the solar system. Studies of terrestrial impact structures, like the Ries impact structure, Germany, have informed on impact cratering processes – e.g., early hot, hydrous degassing, autometamorphism, and recrystallization/devitrification of impact glass – and products – e.g., impact melt rocks and breccias comprised of clay minerals. Yet, clay minerals of authigenic impact origin remain understudied and their formation processes poorly-understood. This thesis details the characterization of impact-generated clay minerals at Ries, showing that compositionally diverse, abundant Al/Fe/Mg smectite clays formed through these processes in thin melt-bearing breccia deposits of …