RESUMfi AND FIELD NOTES. 
163 
9 Mars.—Du No. 80' au No. 81' 13 milles .— 
On acheve de traverser ce lac sale et sec, puis 
les sables modernes qui s’elevent de chaque 
cote sur les montagnes ; puis on vient camper 
dans un canon au pied de la 5 me cliaine, ou il y a 
des roches metamorphiques, des dykes de quartz 
et de greenstone porphyroide. Direction du 
dykes de quartz N. S. 
10 Mars.—Du No. 81' au No. 82'.—On trav¬ 
erse la 5 me cliaine qui n’est pas tres elevee, 
elle est formee en partie de roches metamorphi¬ 
ques, trap, quartzites, et appuyee contre la 
cote de 1’ouest; il y a un enorme drift, 800 a 
1,000 pieds d’ epaisseur ; cailloux assez petits 
entremeles avec du sable grisatre ; ces cailloux 
sont un peu stratifies, non rayes, et quelques 
couches sont cementees par du carbonate of lime , 
et forment un poudingue. Au Camp 82' le 
pays est plus decouvert, il y a beaucoup d’efflor- 
escences salines aux environs du camp. 
11 Mars.—Du No. 82' au No. 83', Ilf 
milles. —On remonte la vallee du Mojave river, 
qui est large avec mesa de drift et dunes de 
sables. Quelques-unes des dunes de sables 
s’elevent sur les montagnes au sud de nous. 
13 Mars. — Du No. 83' au No. 84'.—On con¬ 
tinue a remonter le Mojave ; la vallee est tres- 
large; c’est du drift assez petit. Pres du 
chemin des Mormons, on a des montagnes au 
nord de roches metamorphiques et de porphyre 
rose. Ou nons nons arretons, dans 1’ apres 
midi, il y a des roches metamorphiques. 
14 Mars.—Du No. 84 au No. 85'.—On a les 
memes roches qu’ hier. 
15 Mars. — Du No. 85' au No. 80'.—La vallee 
du Mojave se retrecit trois ou quatre milles 
avant 1’ endroit ou l’on quitte la riviere, et l’on 
voit les roches trapeennes et de mica schistes, se 
trouvant jusqu au bord de l’eau. En quittant 
le Mojave creek on s’eleve graduellement sur 
un plateau forme de poudingue tertiaire. 
16 Mars.—Du No. 86' au N. 87'.—On arrive 
on sominet de Cajon Pass et l’on descend un 
ravin dans le quaternaire ou drift. Ce quater- 
naire, forme de sable endurci aveG cailloux 
March 9.— From Camp No. 142 to Camp No. 
143.—We crossed to the other side of the dry 
and salty lake ; there the recent sands succeed 
and rise on the mountains on each side. We 
encamped in a canon at the foot of the fifth 
chain, where there are metamorphic rocks, 
dykes of quartz, and of porphyroid greenstone. 
The direction of the quartz-dykes is north and 
south. 
March 10.— From Camp No. 143 to Camp 
No. 144.—We crossed the fifth chain, which 
is not much elevated ; it is in part formed of 
metamorphic rock, trap quartzites, resting 
on the side towards the west. There is an 
enormous body of drift, from 800 to 1,000 feet 
in thickness ; the pebbles are rather small, 
and are intermixed with grey sand. They are 
slightly stratified, not in red bands, and some 
beds are cemented by carbonate of lime, and 
form a conglomerate. At Camp 144 the coun¬ 
try is more open, and there are many saline 
efflorescences around the camp. 
March 11.— From Camp No. 144 to Camp 
No. 145, (Ilf miles.) —We ascended the valley 
of the Mojave river, which is wide, and 
bounded with plains, mesas of drift, and sand- 
dunes. Some of the sand-dunes rise on the 
mountains south of us. 
March 13. —From Camp No. 146 to Camp 
No. 147.—We continued the ascent of the Mo¬ 
jave ; the valley is very Avide, and there is 
some fine drift. Near the Mormon road, Ave 
have mountains at the north, of metamorphic 
rocks and roseate-porphyry. There are meta¬ 
morphic rocks Avhere Ave stopped in the after¬ 
noon. 
March 14. —From Camp No. 147 to Camp 
No. 148.—We find the rocks the same as yes¬ 
terday. 
March 15.— From Camp No. 148 to Camp 
No. 149.—The Mojave valley narroAved three or 
four miles before Ave left the river, and we 
saw the trappean rocks and mica-schists as far 
as the border of the stream. On leaving the 
Mojave river, we gradually ascend a plateau 
formed of Tertiary conglomerate. 
March 16. —From Camp No. 149 to Camp 
No. 150.—We arrived at the summit of Cajon 
Pass, and descended a ravine in the quater¬ 
nary or drift. This quaternary is formed of 
