Fig. 1. Photomicrographs of textural features of ALH 84001. Plane polarized (a) and crossed-nichols (b) transmitted-light photographs of thin section ,64. Scale bar in each represents 1 mm. Coarse, deformed orthopyroxene is cut by numerous crushed zones of fine-grained orthopyroxene and chromite. Relatively large interstitial maskelynite (m) is visible at the top center of (a). White veins in (a) are cracks in the thin section. (c) Crossed nichols transmitted light photomicrograph showing remnant primary textures. Note 120° triple junctures and grain boundary offsets on duck-shaped chromite
along fractures. Scale bar represents 0.5 mm. (d) A BSE photomicrograph of a complexly zoned early carbonate associated with euhedral pyrite (p) and enclosed in maskelynite (m). Note offsets in the zoning along fractures (arrow) demonstrating that the carbonates predate the last shock event, and magnesite crystal faces overgrown by Fe-, Ca-rich carbonate of the thicker white band.