126 
GEOLOGICAL REPORT-THIRTY-FIFTH PARALLEL. 
gres. Plusieurs gros blocs cle ces gres per 
cent la surface par suite de la decomposition et 
paraissent comme des boulders. Pas d’allu- 
vions, on trouve plusieurs especes d’ Unio et 
d 'Anodonta, dans le Sans Bois et ses affluents. 
Gros Equiseteum giganteum dans le ruisseau 
pres du camp. 
3 Aout. —Le Docteur traverse la montagne 
et va jusqu’ a 1-a Canadian river; la montagne 
est des sandstone des coal measures et des allu¬ 
vions sabloneux jusqu’ a la riviere. 
4 Aout.—Du No. 9 au No. 10, 17 milles .— 
Toujours sur le carboniferous limestone , pas d’ 
alluvions. Yallees avec montagnes au sud et au 
nord, plus elevees au nord qu’ au sud. Merne 
direction qu’ auparavant. 
5 Aout. —Sandstone plonge au nord sous 
un angle de 15° au second ruisseau, (Gaines’ 
creek). Au sommet, au dessus de la plantation, 
on decouvre un plateau qui ferme la vallee lon- 
gitudinale du Sans Bois. On est eleve a peu 
pres 250 pieds au dessus du Fort Smith. Car¬ 
boniferous limestone toujours. Alluvion sableux 
avec des cailloux de quartz de la grosseur d’ 
un oeuf. 
Camp No. 11, on voit que 1’alluvion a 
change et de sableuse est devenue sablo-caillou- 
teuse. Je fais une collection de 7 ou 8 species 
d’ Unio et Anodonta dans Gaines creek, ou 
South Fork of the Canadian. 
6 Aoid.—Du 11 au 12.—Nons traversons 13 
milles de mamelons de carboniferous sandstones 
avec alternations de schistes, alluvion sableuse 
avec quelques cailloux tres-petits de quartz. 
Beaucoup de lits de sandstone sont tres-ferru- 
gineux. Les assises sout disloquees, meme di¬ 
rection et inclinaison de 10 a 15 degres au nord 
et au sud ouest. 
7 Aout.—Du No. 12 au No. 13, 5 milles .— 
Suivant les couches de corboniferous sandstone 
on trouve 5 ou G specimens de tiges de Sigilla- 
ria, tres-caracteristiques des coal measures , 
the south at an angle of from 20 to 30°. Sev¬ 
eral large blocks of these sandstones pierce the 
surface, in consequence of the decomposition of 
the surrounding portions, and succeed each 
other like boulders. No alluvial deposites 
seen. Several species of Unio and Anodonta 
were found in the Sans Bois and its affluents ; 
also a large Equisetum giganteum in a brook 
near the camp. 
August 3.—The Doctor traversed the mount¬ 
ain, and went as far as the Canadian river. 
The mountain is of sandstone of the coal- 
measures, and is bordered by a sandy alluvium 
as far as the river. 
August 4.— From Camp No. 9 to Camp No. 
10, (17 miles.) —We were always on the carbon¬ 
iferous sandstone ; there is no alluvium. Val¬ 
leys and mountains are visible in the south and 
in the north ; but more elevated in the north 
than in the south. Their direction is the same 
as before given. 
August 5.— From Camp No. 10 to No. 11.— 
Sandstone dips in the north at an angle of 15° 
at the second brook, (Gaines’ creek.) At the 
summit, above the plantation, we discover a 
plateau, which ends the longitudinal valley of 
the Sans Bois. We are elevated about 250 
feet above Fort Smith. Carboniferous sand- 
| stone prevails, as before. Sandy alluvions, 
with pebbles of quartz of the size of an egg. 
At Camp No. 11 we find that the alluvium 
; has changed, and becomes more pebbly. I 
made a collection of seven or eight species of 
Unio and Anodonta in Gaines’ creek, or South 
j fork of the Canadian. 
August 6 .—From Camp No. 11 to Camp 
No. 12.—We crossed for thirteen miles small 
rounded hills of carboniferous sandstone, with 
alternations of shales, and sandy alluvium 
with very fine quartz pebbles. Many of the 
sandstone beds are very ferruginous. The 
strata are dislocated in the same direction, to 
the northeast and southwest, and the inclina¬ 
tion is from ten to fifteen degrees. 
August 7.— From Camp No. 12 to No. 13, 
(five miles.) —We followed the beds of carboni¬ 
ferous sandstone, and found five or six speci¬ 
mens of the stalks of Sigillaria, very charac- 
1 teristic of the coal-measures. 
