664 Ae Die 
Wy 84: Taken at Cambrian Creek, tributary to East Fork of 
Little Bighorn River, long. 10° 45’ W., lat. 44° 50’ N., 34 ft. below 
the flat-pebble conglomerate. 
Description of hand specimen: Limestone, massive, gray-green, 
weathering gray to reddish brown, subsoft, coarse-grained, arena- 
ceous, glauconitic, subvitreous luster, with calcite veins and 1-in. 
crystals; breaks in smooth angular blocks; presents corrugated 
surface where calcite has dissolved on weathering. 
Texture granular-fragmental. Constituents quartz 47 per cent; 
calcite 47 per cent; small amount of glauconite as accessory, and 
limonite as alteration product. Cement calcite. 
Quartz averaging o.3mm., largest grain 0.5 by 1.8mm.; sub- 
rounded; grains broken and healed by calcite; slight traces of 
secondary growth; small grains seemingly fragments of larger ones 
cemented. Calcite shows recrystallization. Glauconite aggre- 
gates about 0.1 mm., rounded. Bryozoan-like fragments. 
Classed: glauconitic trilobitic medium-grained calarenite. 
Wy 66: ‘Taken on south side Tongue River, directly opposite 
mouth of Sheep Creek, 60 ft. below the Cambrian-Ordovician 
contact. 
Description of hand specimen: Limestone, ;/,- to 1-in. beds, 
greenish-white to buff, hard, fine-grained, argillaceous, arenaceous, 
subvitreous luster, slightly ripple-marked, raindrop-pitted (?). 
Texture granular-fragmental. Constituents siderite 30 per cent; 
calcite 30 per cent; quartz 30 per cent; glauconite 5 per cent; a 
little apatite, ilmenite, muscovite, magnetite, and plagioclase; 
muscovite and plagioclase very rare; a little limonite as alteration 
product. 
Calcite averages o.t mm., larger grains 0.2mm. Quartz 0.05 
mm., near-angular to subrounded; inclusions of hematite scales ( ?). 
No fossils. 
-Classed: glauconitic-arenaceous medium-grained siderocalcite. 
Wy 72: Taken on East Fork of Little Bighorn River, 2 mi. 
northeast of Little Bald Mountain, at base of Ordovician “ Bighorn 
dolomite.” 
