12 
MESOZOIC EOEMATIONS. 
a locality. The two horizons are separated by the lignite, and, when this 
is eroded, a double line of hog-backs results. Several miles to the west¬ 
ward of this locality rise the horizontal beds of the Eocene, and the arroyo 
which drains their slope pursues its way eastward into the Gallinas 
Creek. Immediately bordering its valley is a detached hill of Cretaceous 
No. 3, on whose summit stands a large stone building, one of the many 
which strew the crests of all these hog-backs. An account of these is given 
in my report on archaeology.* Further observations on the Cretaceous beds 
are deferred until the Eocene deposits are considered. 
The following is an approximate estimate of the Mesozoic beds in the 
same locality. As they were not accurately measured, the numbers will 
have to undergo revision. Their relative thickness is nearly as given: 
Feet. 
Uncertain (concealed in the sage-plain). 500 
Cretaceous No. 3. 1,500 
Cretaceous No. 2 ... 1,500 
Cretaceous No. 1..... 500 
Jurassic. GOO 
‘•Trias” (bottom not seen). 1,000 
Total . 5,600 
The Mesozoic beds of this section (excepting some of the higher mem¬ 
bers of the Cretaceous) have been examined over extensive areas to the 
west and south by Messrs. Marcou and Newberry, whose valuable reports 
accompany those of Lieutenants Whipple and Ives, on the routes surveyed 
by them through Arizona and New Mexico. The horizon here termed after 
Hayden “Triassic” has been referred previously to this formation by Pro¬ 
fessor Marcou also, who had the opportunity of examining it in Texas and 
the Indian Territory. So far as the latter region is concerned, I can confirm 
the identification, having examined bones from the red beds of that country 
which appear to be those of Belodonts. Dr. Newberry terms it in Arizona 
the “salt group”, or “saliferous sandstones”, referring to it as probably 
including both Triassic and Permian strata. The formations here called 
Jurassic iare partially included by Professor Marcou in his Triassic series, 
and are termed by Dr. Newberry the “variegated marls”, who is inclined 
to refer them to the Jurassic. 
/ 
* Anuuul Kcpoi't Chid' of Engineers, 1875, 11, p. 1080. 
