OF NORTH AMERICA. 
57 
Camp N° 27. — From Atrisco to tlic Rio Pucrco we cross a sandy mountain entirely composed of 
white sandstone of the Upper Cretaceous epoch; fossils are rare, e.xcept pieces of petrified wood. I 
found Ammonites Novi-Mexicani , a piece of a BacuHtes and an Jnoceramiis. 
Camp N° 28. — Almost immediately on leaving the Rio Puerco wo met with a sort of gray marl 
containing a great quantity of nodules of oxide of iron , w ith numerous fragments of fossil silicilied trees. 
These marls are of the age of the Upper Cretaceous epoch. Our camp N° 28 at Alamo is again on 
the New Red Sandstone rocks. 
Camp N° 29. — From Alamo to Laguna the road follow's the foot of bluffs composed of the New 
Red Sandstone rocks, such as white gypsum, dolomite, red sandstone and red marls. Half way to La- 
guna the bottom of the valley is occupied by a lava stream coming from the large extinct volcano of 
Mount Taylor or SioiTa do San Mateo. 
Camp N^ 30. - The bluffs bordering the road on each side arc composed of massive strata of the 
yellowish-white Jurassic sandstone. There is an isolated mountain at the village of Covero, composed 
of Jurassic sandstone and clav, capped at the top by a stream of basaltic trap. The clay contains nu- 
merous fragments of the Gryphcea dilalata var. Tucumcarii. 
Camp N° 31. — We follow the same valley bordered by bluffs of Jurassic sandstone, with a lava 
stream at the bottom of it. This lava stream is one of the most beautiful I have seen , and reminds me 
of the Mer de Glace at Chamounix. Nothing resembles a glacier so much as a lava stream, the differ- 
ence being that one is white and the other dark, and also fhat the lava stream is stopped by the cold, 
while the glacier is only stopped by heat. After seeing a lava stream it is difficult not to admit of a 
certain plasticity in the motion of glaciers. 
Camp N" 32. — Near the camp are seen the strata of the New Red, then a high bluff composed 
of Carboniferous Limestone, and finally the camp is placed on rose colored granite. 
Camp N° 33. — From N° 32 to 33, at Agua Fria, the road follows the junction of the granite with 
the lava stream, and red sandstones of the New Red epoch are seen a little distance to the south of 
our camp. 
Camp N^ 34. — Shortly after leaving the Agua Fria we cross the culminating point of the Sierra 
Madre. We pass on our road a narrow strip of blue-gray limestone of the Lower Carboniferous, a part 
of the numerous strata of the New Red Sandstone epoch, and finally wo cross a large stream of lava 
which occupies the bottom of the valley between the Sierra de Zuni and the mesa or table land of 
Inscription Rocks. On each side of the Sierra de Zuni the strata dip east and west at an angle vary- 
ing from 15 to 40 degrees. 
Camp N^ 35. — I do not find any geological notes in my private journal fur this day's march. 
Camp N° 35 is situated in the narrow valley of Ojo Pescado. The bluffs of the valley' are formed at 
the top of massive strata of rose coloied sandstone, then black marl, intercalated with yellow limestone 
and also containing two or three little seams of bituminous coal, from half to one foot in thickness. All 
the strata are Jurassic. The bottom of the valley is occupied in part by a lava stream. 
Camp N° 36. — We follow' the same valley with Jurassic bluffs on each side and the lava stream 
at the bottom. When we enter the broad valley' of Zuni, the strata of the New Rod Sandstone crop out 
from under the Jurassic rocks, and we establish our camp on the led marl of the Kcuper. The lava 
stream terminates near our camp. 
Camp N° 37. — New Red Sandstone strata. 
Camp N° 38. — - New Red Sandstone strata; all the country round Zuni is of a deep red and Ver- 
million color, and has the same characters as the part of our route between Beaver-town and Antelope- 
hills, Texas. 
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