DESCRIPTION AND NAMING OF SEDIMENTARY ROCKS 659 
Description of hand specimen: Arkose conglomerate, pebbles 
not ranging above ? in. Prevailing color where fresh dark-brown 
shot with gray, the pink of feldspar sharply contrasting; from 
dirty grays and whites of weathered surface pebbles stand out in 
relief. Fucoid markings on what may be bedding-planes 1 in. 
apart. Pebbles 90 per cent quartz, faintly brownish-green, rounded 
to near-angular, breaking with matrix; feldspars pink fresh cleav- 
age fragments. Matrix 90 per cent of rock, sand, fine-grained, 
dull to earthy luster. 
Texture granular-fragmental, large grains showing micrographic 
intergrowth. Constituents quartz 90 per cent; microcline, ortho- 
clase, uncertain plagioclase 8 per cent; small amounts of biotite, 
apatite, zircon as accessories, and sericite, kaolin, limonite, and 
chlorite as alteration products. Liquid and gas inclusions in 
quartz. Cement a sericitic-kaolinic-limonitic ‘“‘mess.”’ 
~ Quartz vari-sized, 1.5 by 0.8 mm. in larger grains, perhaps vein 
quartz, to judge by wavy extinction; average grains, 0.08 mm.; 
rounded to near-angular. Microcline fresh, 0.03 to 0.04 mm. 
Orthoclase same size, largely sericitized. Much organic material, 
seemingly chitinous. 
Classed: ferruginous arkose-conglomerate. 
Wy 93: Taken on Willow Creek at Burgess Ranger Station, 
- 2 ft. above granite. 
Description of hand specimen: Shale, thin-bedded, green when 
fresh, sparsely specked with glistening mica flakes and containing 
lenses of whitish-green sandstone, 1 in. long; on weathered surface 
bluish-black. Hard, arenaceous, fracturing irregularly, fresh sur- 
face of dull luster, bedding-planes subvitreous luster and slightly 
wavy. 
Texture granular-fragmental, pilitic through alteration and with 
parallel arrangement of minerals, excluding quartz. Constituents 
chlorite, sericite, epidote, presumably alterations from biotite, 
muscovite, feldspar; small amounts of quartz, plagioclase, mag- 
netite, zircon. Glauconite indeterminable. Cement a sericitic- 
chloritic felt. 
