CHAPTER V. 
CORRELATION. 
SEDIMENTARY ROCKS. 
Several excursions were taken into the surrounding country for the 
purpose of correlating the formations of the Iron Springs district 
with those of the Colob Plateau, one of the High Plateaus of Utah, and 
with the Pine Valley Mountains. 
The rocks of these areas were first studied in 1871, 1872, and 1873 
by G. K. Gilbert, A. R. Marvine, and E. E. Howell for the Wheeler 
Survey." In 1875, 1876, and 1877, they were studied by Maj. C. E. 
Dutton 6 for the Rocky Mountain Survey and again in 1880 for the 
United States Geological Survey in connection with the work in Grand 
Canyon. In the summer of 1902 a small area east of the Pine Valley 
Mountains along the west margin of the High Plateaus was mapped 
by E. Huntington and J. W. Goldthwait, c under the direction of Prof. 
W. M. Davis, of Harvard University. 
Dutton d classified the rocks of this region int o systems from Carbonif- 
erous to Quaternary. Huntington and Goldthwait 6 subdivided the 
larger division of Dutton to some extent, and applied geographic 
names. The following tables show the correlation of the rocks of the 
Iron Springs district with those given by Huntington and Goldthwait 
and by Dutton: 
a Gilbert, G. K., Report on the geology of portions of Nevada, Utah, California, and Arizona, exam- 
ined in the years 1871 and 1872: U. S. Geog. Surv. W. 100th Mer., vol. 3, Geology, pt. 1, 1875, pp. 17-187. 
Marvine, A. R., Report on the geology of route from St. George, Utah, to Gila River, Arizona, examined 
in 1871: U. S. Geog. Surv. W. 100th Mer., vol. 3, Geology, pt. 2, 1875, pp. 189-225. Howell, E. E., Report 
on the geology of portions of Utah, Nevada, Arizona, and New Mexico, examined in the years 1872 and 
1873: U. S. Geog. Surv. W. 100th Mer., vol. 3, Geology, pt. 3, 1875, pp. 227-301. 
b Dutton, C E., Report on the geology of the High Plateaus of Utah: U.S. Geog. and Geol. Surv. Rocky 
Mtn. Region, 1880, pp. 307; Tertiary history of the Grand Canyon district: Mon. U. S. Geol. Survey, vol. 2, 
1882, pp. 264. 
c Huntington, Ellsworth, and Goldthwait, J. W., The Hurricane fault in the Toquerville district, 
Utah: Bull. Mus. Comp. Zool., Harvard Coll., No. 42 (Geol. Ser., vol. 6), 1904, pp. 199-259. 
d Dutton, C E., op. cit. 
e Op. cit., pp. 202-208. 
62 
