Washington DC: United States Government Printing Office, 1956. Paperback. 303pp. Quarto [29 cm] Gray and black printed wraps. Very good condition. With the large folding Table 21 in the rear pocket, but lacking plates 1 through 4 (originally also in pocket). Item #39993
A comprehensive geologic and petrologic study of the occurrence and origin of the rocks in an area of 12,000 square miles in southwestern Colorado.