12 DIRECTIONS FOR THE MINERALOGICAL AND GEOLOGICAL EXAMINATIONS, 
The best mode of effecting these objects would be, in the first place, to collect sufficient data 
for the construction of a geological section and map, showing the order and succession of rocks 
from the upper Mississippi river to the Pacific ocean. To accomplish this object, careful exam- 
ination should be made of every exposure of rock in place on the route; the dip, or inclination 
from the horizontal; thickness of each stratum of rock exhibited; relative position; and, so 
far as practicable, the lithological character noted. Where outbursts of granite or other 
igneous rocks occur, through the stratified rock, observe the general range of the volcanic 
action; also notice the direction of veins of quartz or other minerals. Specimens for analysis 
should be collected at all important points. ‘Two inches by one of surface, and half an inch in 
thickness, will answer this purpose. Careful barometrical observation should be made, not 
only of the elevations, but at regular intervals, say six times a day, along the whole extent of 
country. The small streams and rivers afford the best opportunity for geological investigations. 
In all cases where the rocks are fossiliferous, collect two or three well preserved specimens; 
these would better determine the age and true position of the rocks than weeks of investigation 
without them ; one or two perfect specimens being far more valuable than a dozen that have 
been rubbed or fractured. 
From the Sioux river to the falls of the Missouri, on both sides of the Missouri, you pass 
through the cretaceous and tertiary formations, perhaps as rich in fossil remains as any other 
region in the country, or it may be in the world. 
Microscopic organic deposits, recent and fossil, are occasionally met with. These infusorial 
remains are sometimes found in layers of considerable thickness, and are well worthy of careful 
investigation. These rocks are silicious and calcareous, usually of a yellowish tinge and some- 
what friable, and have been found in the banks of the Missouri, and in the beds of several of its 
small tributaries. Small specimens should be collected. 
All discoveries of valuable ores, or useful minerals, clays, marls, saline and chalybeate 
springs, &c., should be located, when practicable, by the distance and direction from some 
prominent geographical feature of the country, as mountain, river, &c., and specimens be col- 
lected for analysis. In connexion with this subject it is highly important that a series of 
observations be made on the dip and intensity of the needle, as intimately connected with 
the geological and mineralogical character of that region of country, and as likely to lead to 
results interesting to the cause of general science. Note carefully at all times whether there 
are such indications of valuable minerals as would render expedient a further examination. 
All specimens of rocks, minerals, and fossils, should be wrapped in strong paper, with a label 
of the locality inside written in ink, and packed sufticiently tight, either in bags or boxes, to 
prevent rubbing. Crumbling fossils may be preserved by soaking them in a thin solution of 
glue or gum arabic. 
Specimens of soil for analysis should be collected, and the sub-soil noted, in prairie and 
bottom land, throughout the entire route; at least on every change of surface rocks, as you 
pass over the various geological formations, from the magnesian limestone and lower sandstone 
of the St. Peter’s river, through the vast drift region extending to the Sioux river of the Mis- 
souri, through the various chalk marls, sandstones, plastic clays and slaty clays of the creta- 
ceous formations, the limestone coarse conglomerates and silicious clays of the tertiary period, 
on to the comparatively fertile strip of land caused by the decomposition of the older limestones 
of the Rocky mountains and the vegetable matter washed down from their various slopes, to the 
basaltic soils of Middle Oregon, occupying three hundred miles in extent, and, crossing the 
Cascade range of mountains, to the tertiary soils of Western Oregon. Lach of these soils, so 
different in their constituents, produces different grasses, wild flowers, and trees, and is more 
or less adapted to various agricultural purposes. Hence the vast importance of a careful 
analysis of these soils in advance of the settlement of the country. Bags, made of ticking, 
holding from a pint to a pint and a half, are best suited to a preservation of these specimens. 
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