COMPOSITION, DISTRIBUTION, AND EXCAVATION OF GYPSUM 17 



is referred for a much more detailed discussion of the subject, and from 

 which most of the descriptive matter given below has been abstracted. 



East of the Mississippi River, the producing localities are confined 

 to central and western New York, southwestern Virginia, northern 

 Ohio, and two widely separated areas in Michigan; while a large unworked 

 deposit occurs in Florida. West of that river, gypsum deposits are 

 both numerous and widely distributed, and plaster-mills are in operation 

 in fourteen of the Western States and Territories. 



Brief descriptions of the gypsum resources of the various States 

 are given below, the States being taken up, for convenience of reference, 

 in alphabetical order. 



Arizona. Gypsum can be obtained in quantity at several localities 

 in southern Arizona, the following being particularly noteworthy: 

 (1) In the Santa Rita Mts., Pima County, southeast of Tucson; (2) hi 

 the low hills along the course of San Pedro River, Cochise and Pinal 

 counties; (3) in the Sierrita Mts., Pima County, south of Tucson; (4) in 

 the foothills of the Santa Catalina Mts., Pima County, north of Tucson; 

 (5) on the Fort Apache Reservation, Navajo County. Of these localities 

 only the fourth, north of Tucson, has as yet been commercially developed. 



California. In the Tertiary rocks of California gypsum is widely 

 distributed. It is found throughout nearly all the Coast Ranges, par- 

 ticularly south of San Francisco Bay, in the foothills of the Great Valley, 

 and in the valleys of southern California. Deposits are known to occur 

 in the counties of Fresno, Kings, Monterey, Kern, San Luis Obispo, 

 Santa Barbara, Ventura, Los Angeles, San Bernardino, Riverside, and 

 Orange. 



Colorado. The gypsum-producing localities of Colorado occur at 

 intervals from the northern to the southern border of the State, along 

 the eastern foothills of the Rocky Mountains. "Gypsum has been 

 worked extensively near Loveland: beds have also been opened on 

 Bear Creek, near Morrison, and eight miles to the southeast, on Deer 

 Creek. Quarries have been developed near Perry Park and in the 

 Garden of the Gods, near Colorado City, and also in the vicinity of Canyon 

 City." Other deposits, as yet unworked, are known to occur in the 

 central and western parts of the State. 



Florida. An extensive area of gypsum, 6 to 8 feet thick, has been 

 described as occurring about six miles west of Panasoffkee, Fla., on 

 a low-lying area of hummock-land known as Bear Island. The material 

 has not, as yet, been exploited. 



Iowa. The gypsum of Iowa is confined to a single area of 60 to 70 

 square miles, near Fort Dodge, Webster County. The material occurs 



