Introduction. Acapulcoites and lodranites constitute two related groups of " primitive achon-drites " [1-3] that possess recrystallized textures, chondritic mineralogy, planetary-type rare gases, and approximately chondritic bulk compositions. They are widely considered to have formed by partial melting of chondritic material [4-10]. Although Kallemeyn and Wasson [11] suggested that acapulcoite...

Although asteroid 4 Vesta and Vestoids have been believed to be the source of a group of basaltic meteorites called HEDs, there have been detailed spectral analyses on the spectral redness and the 506.5 nm absorption band, suggesting controversy on their space weathering processes and origins. In order to evaluate a possibility that such an apparent inconsistency may be explained by the space w...

Introduction: Lunar meteorite Dhofar 026 was previously interpreted as an impact melt [1, 2]. Detailed studies of the rock and comparison to Apollo lunar samples 15418 and 60017 indicate that the rock instead is a shocked, partly melted, granulitic breccia. These studies, presented by [3], are summarized herein. Petrology of Dhofar 026: Most of the rock consists of blocky patches of monomineral...

We mapped six distinct glacial moraines alongside Stocking Glacier in the McMurdo Dry Valleys, Antarctica. Stocking Glacier is one of several alpine glaciers in the Dry Valleys fringed by multiple cold-based drop moraines. To determine the age of the outermost moraine, we collected 10 boulders of Ferrar Dolerite along the crest of the moraine and analyzed mineral separates of pyroxene for cosmo...

Ideal pyroxenes are hypothetical structures based on ideal closest-packed arrangements of O anions. They are modeled after observed pyroxene structures and have the general formula M2M1T2O6, where M2 and M1 represent octahedrally coordinated cations, and T represents tetrahedrally coordinated cations. An algorithm has been created to construct all possible ideal pyroxenes based on closest-packe...