298 
CEMENT MATERIALS AND INDUSTRY. 
Generalized section in the Black Hills region — Continued. 
[bull. 243 
Formation. 
Character. 
Average 
thickness. 
Age. 
Sundance 
1 )ark-drab shales and 
buff sandstones; mas- 
sive red sandstone at 
base. 
Feet. 
60-400 
Jurassic. 
Spearfish 
Minnekahta limestone. 
Red sandy shales with 
gypsum bed. 
Thin-bedded gray lime- 
stone. 
350-500 
30-50 
Triassic. 
Permian. 
( >peche. 
Red slabby sandstone 
and sandy shale. 
90-130 
Permian? 
Minnelusa 
Sandstones, mainly buff 
and red; in greater 
part calcareous. Some 
thin limestone in- 
cluded. 
400-450 
Carboniferous. 
Pahasapa limestone 
Massive, gray limestone. 
250-500 
Do. 
Englewood limestone.. 
Pink slabby limestone. . 
25 
Do. 
Dead wood 
Red-brown quart zite 
and sandstone, locally 
conglomeratic, partly 
massive. 
4-150 
Cambrian. 
1 
Of the various formations named in the above tables, the limestones 
are described by the same writer/' 
ENOLEWOOD LIMESTONE. 
In the southern Black Hills the Deadwood formation is overlain by a series of thl 
bedded, pale pinkish-buff limestones. On the suggestion of Mr. Jaggar, it is proposes 
to designate this formation the Englewood limestone, from a locality in the norther: 
Black Hills where it is extensively exposed. It appears to extend continuous! 
around the Black Hills, everywhere immediately underlying the Pahasapa limestonw 
It averages 20 to 30 feet in thickness and presents frequent outcrops in the lowt 
slopes of the limestone escarpment and in numerous canyons. It merges rapidl I 
into the overlying limestone, occasionally with a few feet of impure buff limestoDi 
intervening. It is usually sharply separated from the Deadwood formation, but onl I 
by a sudden change in the ?iature of the materials. The Englewood limestone i 
usually fossiliferous, containing numerous corals and occasional shells. The follow i 
ing forms have been reported: Fenestella, Orthothetes, Leptama, Spirifer, Chondki 
logani, Reticularia peculiaris, Syringothyris carteri, and crinoids. It is correlated wit.il 
the Chouteau or Kinderhook of the Mississippi Valley. 
PAHASAPA LI M ESTONE. 
This prominent member, heretofore known as the gray limestone, has an extensiv 
outcrop area in the Black Hills uplift. It constitutes much of the high, wide platea 
" [bid., pp. 509, e1 seq. 
