Introduction: Phase transformations occurring during severe meteoritic impacts on planetary bodies are crucial indicators for estimating maximum shock pressures and temperatures. Their identification is not only essential for a detailed understanding of the shock history and origin of these meteorites, but also for deciphering their pre-shock petrology and magmatic evolution. Most shock-induced...

Introduction: Since 1999, the lunar sample collection has been supplemented with about 50 meteorites from the Moon. Many of these stones are paired, and the total number of different lunar meteorites in the present collection is 37. Of these 37, five are lunar mare basalts, which represents ~14% of the lunar meteorite collection. Considering that the maria represent ~17% of the lunar surface, t...

Introduction: The study of terrestrial analogs to Martian igneous rock compositions and surface features is important in order to gain insight into past and present dynamic processes experienced on Mars. Previous Martian analog studies have been performed on materials from various terrestrial environments [e.g., 1-3]. For this study, we investigated petrological and mineralogical properties of ...

Introduction: Yamato 980459 (Y98) is an olivine-phyric basaltic shergottite [1] composed of 48% pyroxene, 26% olivine, 25% mesostasis, and 1% other minerals. Unlike the other Martian basalts, it contains no plagioclase. Olivine in Y98 is the most magnesian of all Martian meteorites. Thus Y98 is believed to be the most primitive [2] and its composition may be the closest to a primary or direct m...

Introduction: We have studied the petrography and Fe-isotope composition of seven chondrules, four from the Allende (CV3) carbonaceous chondrite and three from the Chainpur (LL3.4) ordinary chondrite. Three textural-chemical chondrule types are represented within this sample set: (1) BO, (2) RP and (3) PO/POP. These textural differences allow us to exa mine the Fe-isotope composition in materia...

Introduction: Micrometeorites are that fraction of the extraterrestrial dust flux that survives atmospheric entry to be recovered from the Earth’s surface. The majority of large micrometeorites (>50 μm), recovered from Antarctic ice, experience significant heating during atmospheric entry with the result that volatilebearing phases, such as clay minerals, have thermally decomposed. A significan...

Introduction: The metamorphosed CK chondrites frequently contain evidence of shock darkening of silicates, a feature which has been documented by several authors [1,2]. This darkening is the result of shock mobilization of sulfides and their injection into silicate minerals forming micron to submicron inclusions. Several studies have observed matrix olivines in CK chondrites which appear to be ...

Introduction: Libourel and Krot [5] reported the discovery of lithic clasts having granoblastic texture and composed of forsterite and Fe,Ni-metal within Type I chondrules from the CV carbonaceous chondrite Vigarano. They suggested that Type I chondrules consist of an inherited, relict component, mainly forsteritic olivine and ±Fe,Ni-metal, originated from olivine-dominated (dunite-like) mantle...

Introduction: The Lu-Hf decay system can be used to resolve planetary differentiation timescales, but this application requires knowledge of Hf isotopic evolution for bulk planets. Because Lu and Hf are refractory and lithophile, the isotopic evolution of bulk planets and their silicate portions can be reconstructed by back-calculation from the present-day Hf/Hf and Lu/Hf in chondrites [1–3]. H...

Introduction: Amoeboid Olivine Aggregates (AOAs) are irregular-shaped, fine-grained aggregates of olivine and refractory minerals and are important components of C chondrites. The AOAs in CV chondrites have been interpreted to be primary nebular condensates [1] and therefore, can provide constraints on models for nebular condensation. AOAs are intermediate in composition, and may be a link, bet...