RESUM £ AND FIELD NOTES. 
169 
vallee s’elargit de nouveau et l’on est encore 
entre deux couches de diluvium assez abond- 
ant, et le meme que precedemment. 
13 Fevrier.—Du No. 61' au No. 62', 6| 
milles. —On passe des montagnes de trap amyg- 
daloide, rougeatre du systeme N.S. qu’ont re- 
leve des gres et poudingues rouges tertiaires, 
probablement pliocene le gres rouge tres-fin et 
differente de la couleur du gres rouge plus 
ancien. La vallee s’elargit, et est remplie de 
diluvium plus petit que dans le canon. Le sys¬ 
teme nord sud finit a peu de distance au sud 
de nous, et une nouvelle chaine du systeme 
E.E.S. a O.O.N. commence au sud de nous. 
15 Fevrier. — Du No. 61' au No. 62', 9|- 
milles. —On entre bientot dans un canon de 
sept milles de long qui traverse une troisieme, 
chaine des monts Cerbat, E.E.S., O.S. N. ce 
canon --[?] abrupte a montagne et cliff de 
300 a 600 pieds, est forme de roches metamor- 
phiques, conservant des indices de stratifi¬ 
cation avec quelque plications. Les roches 
sont des quartzites blanchies, par veines; alter¬ 
nant avec des micaschistes bruns noirs et verts; 
il y a des veines de fer dans le canon. Au sortir 
du canon on a un immense developpement de 
drift qui semble indigner le voisinage du Rio 
Colorado Grande. 
16 Fevrier.—Du No. 62' au No. 63', 6 
milles f.—On entre de nouveau dans un canon a 
un mille de distance ; ce canon est forme de ro¬ 
ches trappeennes et de quartzites metamorphi- 
ques. Puis on entre dans une region de pou- 
dingue rouge et de gres rouges tertaires. Les 
Poudingues sont redresses par le systeme Nord 
sud qui vient-[?] ici centre le sys¬ 
teme Mogoyon. Vallee assez etroite. 
17 Fevrier.—Du No. 63' au No. 64' 7 
milles —L’eau disparait encore, le canon est 
large mais le lit sableux de la rive, l’occupe en- 
terement ; a gauche systeme Mogoyon a droite 
systeme Cerbat; memes roches eruptives et 
metamorphiques, basaltiques, formant le som- 
met d’une mesa, a droite pres de Camp 64'. 
mountains. The valley again widens, and we 
are still between two beds of diluvium, which is 
abundant, and the same as before. 
February 13.— From Camp No. 120 to No. 
121, (6^ miles.) —We passed mountains of 
amygdaloidal trap of a reddish color, and be¬ 
longing to the north and south system. They 
have raised same Tertiary sandstones and con¬ 
glomerates of a red color, probably pliocene. 
This very fine red sandstone is very friable, and 
has a reddish-yellow color, which differs from 
the color of the older red sandstones. The valley 
widens, and is filled with diluvium smaller 
than in the canon. The north and south sys¬ 
tem ends at a short distance south of us, and a 
new chain of this system E.E.S. to W.W.N. 
commences at the south of us. 
February 15.— From Camp No. 121 to No. 
122, (9£ miles.) —We soon entered a canon 
seven miles long, which crosses a third chain 
of the Cerbat mountains, which has the direc¬ 
tion of E.E.S. and W.W.N. This canon is 
abrupt, with a mountain and cliff of 300 to 
600 feet high, formed of metamorphic rocks, 
preserving indications of the stratification, with 
some plications. The rocks are of quartzite, 
whitened by veins, alternating with brown, 
black and green mica-schists. There are some 
veins of iron ore in the canon. On leaving the 
canon we found an immense development of 
drift which appears to indicate the vicinity of 
; the Great Colorado river. 
February 16. —From Camp No. 122 to No. 
123, (6§ miles.) —At the distance of a mile from 
camp we again enter a canon, which is composed 
of trappean rocks and metamorphic quartzite ; 
we then enter a region of red pudding-stone 
and Tertiary red sandstones. The conglomer¬ 
ates are raised up by the north and south sys¬ 
tems, which interfere at this point with the Mo¬ 
goyon system. The valley is rather narrow. 
February 17.— From Camp No. 123 to No. 
124, (1{-miles.) —We are yet without water. 
The canon is wide, but is entirely occupied by 
the sandy beds of the river. The Mogoyon 
system is on the left, and the Cerbat mountains 
are on the right. We find the same metamor¬ 
phic and eruptive rocks. In the Cerbat mount¬ 
ains there is much basaltic trap forming the 
summit of a mesa on the right near camp. 
