Introduction: The early Late Devonian, wet-target Alamo Event at southern Nevada resulted in one of the best-exposed and well-dated impact deposits ever documented, the Alamo Breccia [1]. Because post-impact geologic processes have modified, obscured [2, 3] and perhaps wiped away its original morphological and architectural relationships, the crater stratigraphy has remained uncertain. Thus, th...

This paper reports the detailed examination of three basalt clasts from Apollo 16 breccia 60639 that represent a new variant of high-Ti basalt returned from the Moon by the Apollo 16 mission. Mineral chemistry and whole-rock analyses were conducted on aliquots from three clasts (breccia matrix, basalt, and basalt + breccia matrix). The basalt clasts, which are not overtly porphyritic, contain c...

Misra [1] has strong reservations on our finding of Archean crustal signatures in the Lonar crater impact breccia. Our inference was based on textural, mineralogical, trace element and Nd, Sr, Pb isotopic analyses of the target basalts and the impact breccia rocks of the crater [2], whereas Misra's arguments are based on the non-in situ nature of some of the impact breccia samples of the crater...

High-pressure polymorphs recovered in terrestrial craters are evidence of meteoroid impact events on the Earth’s surface. Despite countless impact craters on the Moon, high-pressure polymorphs have not been reported to date in returned Apollo samples. On the other hand, recent studies report that the high-pressure polymorphs of silica, coesite and stishovite occur in shocked lunar meteorites. W...

The Lonar impact crater in the Deccan Traps of the Indian peninsula provides unique opportunities to study physical and chemical processes of impact cratering on basaltic targets, because terrestrial impact craters on basalts are extremely rare. Such studies are needed for determining provenance and other parameters of the excavated rocks and the cratering phenomenon that may have implications ...

available online at http://meteoritics.org 1675 © The Meteoritical Society, 2006. Printed in USA. Breccia dikes and crater-related faults in impact craters on Mars: Erosion and exposure on the floor of a crater 75 km in diameter at the dichotomy boundary James W. HEAD* and John F. MUSTARD Department of Geological Sciences, Brown University, Providence, Rhode Island 02912, USA *Corresponding aut...

Introduction: The formation of impact related pseudotachylitic breccias and their occurrence in large impact structures such as Vredefort and Sudbury is still a matter of debate. The main formation processes that are currently considered – in the absence of large-scale fault/shear zones where massive friction melts could be generated-are shock melting, frictional melting and decompression melti...

Large volumes of carbonate breccia occur in the late syn-rift and early post-rift deposits of the Billefjorden Trough, Central Spitsbergen. Breccias are developed throughout the Moscovian Minkinfjellet Formation and in basal parts of the Kazimovian Wordiekammen Formation. Breccias can be divided into two categories: (i) thick, cross-cutting breccia-bodies up to 200 m thick that are associated w...

Introduction: In simple impact craters like Barringer Meteorite Crater (aka Meteor Crater), very little molten material was generated. There are no detectable melt ponds within the breccia lens or any significant melt pools on the crater walls or in the ejecta blanket. There was either an insufficient volume of melt produced by the impact event and/or it was too finely disseminated, possibly be...

Through this work I engaged the geological process of brecciation as a metaphor in an arts-integrated critical analysis event that changed trajectory my career and initiated transformation relationship with geoscientific knowledge professional practice. integrated personal stories from time exploration geologist Red Lake, ON, reflections on current role post-secondary geoscience educator, to sp...