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 sufficiently 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. Each of these soils, so 

 different in their constituents, produces different grasses, wild tiowers, 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. 



