John Strong Newberry. — Stevenson. 7 
reached that the area of land in the western regions must have 
been greater than supposed by most writers, for otherwise one 
can not account for the accumulation of such vast thickness - 
of sediment as are shown in the region crossed by his party. 
Here too is presented the ingenious theory respecting the 
occurrence of gypsum with red shale, that it is due to the 
action of decomposing pyrite on calcium carbonate and shale. 
This report contains a recognition of Triassic, Jurassic and 
Cretaceous in the Mesozoic and of the Coal Measures in the 
Paheozoic. 
The report of the expedition with ('apt. Macomb* was pub- 
lished in 1876 as prepared in 1S60, and its author had good 
reason for self-congratulation upon the success with which it 
stood the test of later studies by others. It was at once an 
amplification and a revision of his previous work. The route 
was from Independence. Mo., to Santa Fe, the line being dif- 
ferent from that followed on the return from the Colorado 
river expedition. Thence the course led to the junction of the 
Grand and Green rivers "of the Great Colorado of the west." 
An especial feature of this report is the full identification of 
the Upper Missouri Cretaceous section in New Mexico and 
Arizona, though the subdivisions recognized by Meek and 
Ha} T den at the north could not be made out in full detail at 
the south. Dr. Newberry's grouping is: — 
Lower Cretaceous, equivalent to No. 1 of the Upper Missouri. 
Middle Cretaceous, equivalent to Xos. 2, 3 and 4 of the Upper Mis- 
souri. 
Upper Cretaceous, equivalent to No. 5 of the Upper Missouri. 
But the enormous thickness of the Upper Cretaceous led him 
to surmise that part of it might be Tertiary. Detailed de- 
scriptions of Cretaceous make up much of the volume. Juras- 
sic was recognized with some hesitation at Beveral localities, 
but the gypsum-bearing formation of New Mexico wm< placed 
in the Trias without hesitation because of the plant- discov- 
ered in the old copper mines of Abiquiu. The Cretaceous 
sandstones, both Upper and Lower, were found to contain 
leaves of angiospermous plants, not merely in eastern New 
*Report of the Exploring Expedition from Santa Fe, Xew Mexico, 
to the junction of the Grand and Green rivers of the Great Colorado of 
the West, in 18o9, under the command of Capt.J. X. Macomb; with Geo- 
logical Report by Prof. J. S. Xewberry. geologist of the expedition. 
Washington, L876. 4to, pp. 148, map and 19 plates. 
