GEOLOGY. 



GEOLOGICAL SURVEYS OF THE UNITED STATES. 



AT the recent meeting of the American Association, resolutions 

 were offered, strongly urging the completion of geological surveys of 

 the several States of the Union which still remain unfinished. There 

 are several cases of this kind, and the interests of the State, the 

 country, and of knowledge, strongly demand that the work be carried 

 forward. Large portions of our territory, rich, it may be, in wealth of 

 minerals, building material, fertile soil, and various productions valuable 

 in the arts, remain unexplored, and, where explorations have been made, 

 there have been delays in the publication of reports, which are not 

 creditable to the legislatures that have this matter in control, nor 

 just to those who have been laboring in the surveys. Sillimari's 

 Journal, 



GEOLOGY OF THE GOLD REGIONS OF CALIFORNIA. 



THE following account of the geology of the gold regions of Califor- 

 nia is compiled from various sources. The region of the Sacramento 

 is remarkable for the great extent of its alluvial plains or flats. Two 

 hundred miles from its mouth they are twenty miles wide, but near Sut- 

 ter's Fort the width is between fifty and sixty miles. The country about 

 Sutter's Fort during the winter is mostly covered with water, and the 

 same is true of the bottom-lands of the rivers of the gold region. All 

 the gold thus far discovered occurs uniformly in one geological forma- 

 tion. This is the stratum of drift, or diluvium, composed of a heteroge- 

 neous mixture of clay, sand, gravel, and pebbles, and varying in thick- 

 ness from a few inches to several feet. There are many boulders 

 lying directly beneath the soil, and resting on the rocks below, which, 

 in most of the diggings, consist of gneiss or clay-slate, running about 

 north-northwest and south-southwest, and dipping nearly perpendic- 

 ularly. The stratum of diluvium is, however, neither horizontal nor 

 of uniform slope, but conformed to the varying inclination of the 



