Gilbert’s Geology of the Henry Mountains. 17 
Art. Il.—Gilbert’s Report on the Geology of the Henry 
Mountains.* 
Mr. GILBERT presents much that is new to Geology in his 
account of the Henry Mountains. These mountains—so name 
y Mr. Powell in honor of Professor Joseph Henry—are situated 
in Southern Utah, about the meridian of 110° 45’, and the par- 
allel of 38°. They are an irregular group—not a range—of 
five mountains, the highest about 5,00 feet above the arid 
plateau at their base, and 11,000 feet above the sea. It is 
stated that although much cut up by vallies of erosion, they 
still show, to some extent, 
by their forms, but chiefly 
by the dip of their beds, that 
they were originally mammi- 
form bulgings of the strata of 
the region, or groups of such 
bulgings. The accompany- 
Ing figure is a ground-plan 
of the Henry Mountains: N, 
Mt.Ellen; P, Mt. Pennell; H, 
Mt. Hillers; M, Mt. Holmes; 
KE, Mt. Ellsworth; it rep- 
resents N (Mt. Ellen), P (ate 
alone as single, The single 
bulgings or domes vary in 
diameter from half a mile to | ~ 
four miles, and the outline is Scole of 
nearly circular or somewhat Sa 
oval, though more or less 
irregular where they have en- Map of the Henry Mountains. 
croached on one another. 
The strata constituting them are those of the Cretaceous 
formation, which comprisés, beginning above, the “ Maruk,” 
Blue Gate” and “ Tununk” sandstones, and “ Henry’s Park 
Group,” and has there a thickness of 3,500 feet; the Jura-Trias, 
which is divided into the “Flaming Gorge,” “Gray Cliff,” 
port on the Geology of the Henry Mountains, by G. K. Girpert. U. 8. 
Geographical and Geological Survey of the Rocky Mountain Region, J. W. PowELL 
in charge. 160 pp. 4to, with plates, maps, and sections. De artment of the 
Interior. Washington, 1877. Although this date makes the printing of the Report 
to have been done in 1877, the volume has i ithi t 
Am. Jour, —. Serizs, Vou. XIX.—No. 109, Jan., 1880. 
