MISCELLANEOUS MINERALS. 65 
VOLCANIC ASH. 
A deposit of volcanic ash is exposed on the south end of a low 
mesa in the NW. \ sec. 6, T. 13 N., R. 73 W., a mile northeast of 
Sportsman Lake. The section here is as follows: 
Section of volcanic ash deposit near Sportsman Lah . 
Buff sandstone and conglomerate 1 
Volcanic ash 4-5 
Red clay 5 
Volcanic ash 5 
Red shale to bottom of slope. 
The material is a pure white, massive, soft, fine-grained rock which 
has been prospected under the supposition that it was kaolin and 
''aluminum ore." Under the microscope it is seen to be volcanic 
ash. The following analysis shows its composition: 
. 1 an lysis of volcanic ash near Sportsman Lake. 
Silica (Si0 2 ) 67 
Alumina and iron oxide i Al 2 < > ; $. Fe 2 3 ) 16 
Lime (CaO) 1 
Soda (Na 2 0) 2. 8 
Potash (K 2 0) 5 
Water (by difference) 8. 2 
100 
The upper bed has been opened in two or three places within a 
quarter of a mile. It appears to be approximately level and is cov- 
ered by 1 to 2 feet of sandstone overlain by 3 to 4 feet of gravel. 
Probably the deposit is not extensive, for it does not outcrop in other 
poit ions of the area. Its age is either Quaternary or Tertiary, more 
probably the latter, though there is no decisive evidence to indicate 
to which system it belongs. 
CEMENT. 
Materials for the manufacture of cement exist in large amount in 
the Laramie Basin, but they have not as }^et been utilized. One of 
the most promising rocks is the impure limestone of the Niobrara 
formation, which is of wide distribution. The limestones of the 
Casper, Chugwater, and Morrison formations mighl also l>e wsvd 
mixed with Benton or other shales or alluvial clays to afford the nec- 
essary constituents. 
SAND. 
Large amounts of sand for building and other uses are obtainable 
from the terraces and alluvial deposits throughout the Laramie 
Basin. Sand for the glass works formerly in operation at Laramie 
58050— Bull. 364 09 —5 
