Index No: MRTN102350; Collected By: Thomas B. Nolan; Sample Type: hand sample; thin section; Notes: Location taken from Ohio Tonopah Mine shaft; Fine-grained, green clastic rock with a dense green matrix containing small to large white, angular feldspars. The variation in size and amount gives the rock a banded appearance. The widest bnads contain the finer material and are up to 5 cm wide. The coarser bands may be as small as 1 cm wide. The groundmass is chiefly small sericite shreds with flakes of altered biotite and angular quartz fragments. Apatite and zircon are present, but feldspar phenocrysts, if present, have been practically all torn out. This rock looks much more like a member of the tuff series rather than CA. Rutile is [...]
