684 R. W. RICHARDS AND G. R. MANSFIELD 
Bloomington formation (bluish-gray, more or less thin-bedded ££ 
limestones and argillaceous shales; small rounded nodules of 
calcite are scattered irregularly through many of the layers of 
TEMESEOME) ee 5: eas a Re ae ieee cae ais AAI ies ie cso eu gL A ea 1,162 
Blacksmith limestone (gray arenaceous limestones i in massive layers) 23 
Ute limestone: 
Blue to bluish-gray thin-bedded fine-grained limestones and 
shales, with some oolitic, concretionary, and interformational 
conglomerate layers). 6 cnt Faw eis ti eee ee ee 731 
Spence shale member (argillaceous shales)........ a 30 
Langston limestone (massive-bedded bluish-gray Iimestone wath 
many roundedsconeretions) 2.24.14 nee oe eee 30 
Brigham quartzite (massive quartzitic sandstones)............. 1,000 
Two of the formation names, those of the Wells and Phosphoria 
formations, and the name of one subordinate member, the Rex 
chert, appear for the first time in the above table. A discussion 
of the application of these names and detailed descriptions of the 
beds to which they are applied follow. 
PHOSPHORIA FORMATION 
The name of the Phosphoria formation is derived from Phos- 
phoria Gulch, which joins Georgetown Canyon at a distance of 2.5 
miles N. 16° W. of Meade Peak, Idaho, in which the formation is 
typically exposed. 
The name of the Rex chert member is derived from Rex Peak 
in the Crawford Mountains, Rich County, Utah,.where the chert 
forms an anticlinal cap. This locality has been described by Gale 
(roa) and the selection of the name for the member was originally 
made by him. 
The following section is complete and representative of the 
formation as exposed in the region about Phosphoria Gulch, Idaho. 
COMPLETE SECTION OF PHOSPHORIA FORMATION, INCLUDING THE REX CHERT 
MEMBER, MEASURED IN SECTION 12, T. 10 S., R. 44 E., AND 
PHOSPHATE SHALES IN PROSPECT PIT IN SECTION 7 OF 
A Dea key ay 1a ly Dp 
Thickness 
Description Ft. Tn. 
Shale, black, cherty, weathers red-brown to purple Sr eaile sere suirts 80 
Chert; in heavilyniron-stained edges ses pea eee 60 
