Index No: NBM055780; Collected By: ; Sample Type: hand sample; Notes: Rock chip sample of poorly welded, vapor-phase crystallized ash flow tuff (Tcr) with pervasive strong red-orange iron oxide stain. Mn-Fe oxide coats fracture surfaces. Partial argillic alteration of groundmass and plagioclase and mafic phenocrysts; sanidine and biotite phenocrysts are fresh. -Weiss, 4/6/95.