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...

Nanobacteria-like objects evidenced at the surface of the orthopyroxenes of the Tataouine meteorite in South Tunisia have been studied by scanning and transmission electron microscopies. A method of micromanipulation has been developed to ensure that exactly the same objects were studied by both methods. We have shown that the nanobacteria-like objects are spatially correlated with filaments of...

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...

Introduction. The Wark-Lovering rims [1] found on many refractory inclusions are important recorders of nebular environments to which refractory inclusions were exposed after their formation, such as different temperature regimes and isotopic reservoirs [2]. As part of a large-scale survey of W-L rims to enable us to better understand the range of environments reflected in rims, an inclusion of...

Introduction: Ca-Tschermak (hereafter CaTs), CaAl 2 SiO 6 , component has been one of the most important hypothetical members of pyroxene, and CaTs-rich pyroxene was abundantly reported from refractory inclusions in carbonaceous chondrites [e.g., 1]. However, the nature of such pyroxene has not been characterized in detail because of their tiny grain size. For the first time, we succeeded to id...

Introduction: The metal-rich CH and CB chondrites are among the most primitive (unmetamorphosed, unaltered), but controversial meteorites: both nebular and asteroidal models have been proposed to explain the origins of their components [1-14]. In addition to porphyritic chondrules and rare refractory inclusions, the CHs contain a high abunbance (~20 vol%) of metal and dominant cryptocrystalline...