Lingunite nanocrystals and amorphous plagioclase (maskelynite) are identified at the contacts between augite and labradorite wedge-shaped interfaces in the doleritic rocks of the Lockne impact structure in Sweden. The occurrence of lingunite suggests that the local pressure was above 19 GPa and the local temperature overwhelmed 1000 °C. These values are up to 10 times higher than previous value...

Introduction: Basaltic rocks available for laboratory study include samples from the Earth, Moon, Mars and at least seven asteroids – the parent bodies of eu-crites (probably 4 Vesta), angrites, mesosiderites, and Shock Effects in Retrieved Lunar Rocks: None of the shock effects in Apollo samples were produced during launch of these rocks off the lunar surface. Consequently , most Apollo mare b...

The Pb isotopic compositions of maskelynite and pyroxene grains were measured in ALH84001 and three enriched shergottites (Zagami, Roberts Massif 04262, and Larkman Nunatuk 12011) by secondary ion mass spectrometry. A maskelynite-pyroxene isochron for ALH84001 defines a crystallization age of 4089 ± 73Ma (2σ). The initial Pb isotopic composition of each meteorite was measured in multiple maskel...

Introduction: Apatite has been extensively studied on Earth because of its geological, geobiological, and materials importance [1], and it is one of the most common mineralogical reservoirs for phosphorus on Earth. Apatite is also present in each of the three types of SNC meteorites, implying the same may also be true for Mars. In addition to phosphorus, apatite commonly contains some combinati...

Nearly a decade ago, Gorter (1) suggested that the Bedout basement high, offshore Western Australia, might represent an impact structure, in view of the site_s well-defined circular Bouguer anomaly and seismic reflection data indicating a possible ring syncline. Recently, Becker et al. (2), as part of the search for the cause or causes of the mass extinction that marks the Permian-Triassic (P-T...

Introduction: Most martian meteorites are highly shocked, with plagioclase transformed to maskelynite or even melted and partially crystallized [1,2]. These responses to shock conditions on Mars provide clues to the nature of the ejection events for martian meteorites and to local shock conditions. Where new-to-science phases are discovered, meteoritic occurrences can also inform the study of e...

IN SHERGOTTITE. M. Kayama, T. Nakazato, H. Nishido, K. Ninagawa and A. Gucsik Research Institute of Natural Sciences, Okayama University of Science 1-1 Ridai-cho, Okayama, 700-0005, Japan ([email protected]), Department of Applied Physics, Okayama University of Science 1-1 Ridai-cho, Okayama, 700-005, Japan, Max Planck Institute for Chemistry, Department of Geochemistry, Joh.-J. Becherweg 27...

Introduction: Minerals subjected to high shock pressures exhibit structural changes with increasing pressure (e.g., fractures, deformations, formation of diaplectic glass, and complete melting [1-6]). Petrologic and thermal infrared spectroscopic studies have shown that diaplectic glass (maskelynite) formation in feldspars occurs between ~25-45 GPa, while significant melting occurs above ~45 GP...