2. Autoclastic chert with clay
General Atlantic, Tjaden 1A1 WIW #1, 4337 ft, autoclastic chert breccia with clay infiltration below arrow. Interpenetrating clasts of brown porous chat. Thin section photomicrograph from 4398 ft. contains autoclasts lined by clay and brown microcrystalline calcite. Abundant microporosity, molds, and vugs in spiculitic microcrystalline chert (chat). Scale bar is 0.1 mm. Plane polarized light and blue epoxy impregnation