l.J NEBRASKA. 229 
PORTLAND-CEMENT RESOURCES OF NEBRASKA. 
The possible sources of cement materials in Nebraska are confined 
the formations of Carboniferous and Cretaceous age. Named in 
der, from above downward, these include the following: 
Laramie formation Yellowish and greenish sandstone and 
shale. 
Pierre clay Dark -gray clay or soft shale. 
.{Niobrara formation Chalky limestone. 
Benton shale : Dark-gray or black shale or clay. 
(Greenhorn limestone) . . . (Limestones in Benton shale. ) 
Dakota sandstone Brown sandstone. 
Permian limestone Buff limestones and shales. 
Cotton \v 1 limestone Massive light-colored limestone. 
Wabaunsee formation Limestones, shales, sandstones, and thin 
coal beds. 
coniferous. J 
CARBONIFERO US FORMA TTOXS. 
The Carboniferous limestones, shales, and sandstones underlie all of 
Nebraska, rising to the north and northwest about the Black Hills and 
[id on the slopes of the Rock}^ Mountains. The outcrops in eastern 
Nebraska are in Douglas, Sarpy, Cass, Lancaster, Otoe, Gage, John- 
Dn, Pawnee, Nemaha, and Richardson counties. The rocks are hard 
nd would give rise to more prominent features in this region if it 
r ere not for the heavy covering of glacial drift and loess. As it is, 
le exposures constitute cliffs along Platte River from Ashland to 
lattsmouth, and thence at intervals along Missouri River to the 
outheast corner of the State, and occur in scattered outcrops along 
le valleys of Big Blue, Nemaha, and Little Nemaha rivers and Weep- 
lg Water, Turkey, and Southeast Salt creeks and their branches. 
The Upper Carboniferous rocks in this region comprise formations 
f Permian and Upper Coal Measure or Pennsylvania age. The Per- 
lian outcrops are probably restricted to the valley of Big Blue River 
rom Beatrice southward. The rocks are mainly magnesian limestones 
f light color, with interbedded shales. They are extensively exposed 
outh of Beatrice, at Rockforcl, Bluesprings, Wymore, and Holmes- 
ille. The other Carboniferous members appear to comprise the Cot- 
onwood and Wabaunsee formations of the Kansas geologists. They 
onsist of limestones, shales, and sandstones, which contain thin coal 
)eds in some localities. Professor Prosser has made a preliminary 
examination of the Carboniferous formations of Nebraska, and identi- 
iesas Wabaunsee the exposures about Peru, Aspinwall, Nebraska City, 
aDarton, N. H., Preliminary report on the geology and water resourcesof Nebraska west of the One 
mndred and third meridian: Prof. Paper U. S. Geol. Survey No. 17, pp. 14-20. A colored geologic 
nap of Nebraska, showing the surface distribution of all the formations, forms PL IX of the report 
ited. The data concerning Nebraska cement material have been obtained from Mr. Darton's report, 
vhich is in part cited verbatim. 
