GEOLOGY. 295 



in gold-seeking has not exceeded in value $3.00, a sum which will 

 barely pay the expenses of living in that country. 



As regards the evidence of diluvial action in California, Mr. Tyson 

 says, " The boulders scattered in the region of the Mokelemy, even 

 on the highest grounds, prove that the vast floods which prevailed dur- 

 ing a former period in the earth's history, and which bore icebergs 

 from the northward, over Europe, Asia, and the northeastern portion 

 of North America, also carried them over parts of California." It 

 was during this era, that the large valleys along the California rivers 

 were formed, by the removal of conglomerates, sandstones, &c., some- 

 times to the extent of twenty miles in area. During this erosion, the 

 gold in 'u\o veins of the rock destroyed was liberated, and borne by vir- 

 tue cf its great specific weight to the bottom of ravines, where the 

 force of the currents and great depth of the torrents were sufficient to 

 leave nothing else of less comparative weight behind. As these cur- 

 rents decreased in force, the heavier stony fragments began to be de- 

 posited, and mix with, and cover th auriferous and other metallic sub- 

 stances : but the gravel and sand continued on, and formed the im- 

 mense bees now seen upon the rolling country at the foot of the moun- 

 tains, while much of the finer materials was carried further, even into 

 the ocean itself, through openings probably formed at that period in 

 the coast range. 



There is a tradition among the Indians to the effect, that the narrow 

 strait which connects the ocean with the Bay of San Francisco was 

 effected within a recent period (about four generations ago) and that it 

 was suddenly done. Much greater effects than the sinking of a suffi- 

 cient area to have opened this narrow passage have been produced by 

 earthquakes within the last 200 years. Besides, the coast range bears 

 incontestable marks of being within a district wherein internal disturb- 

 ing forces have acted with violence sufficient to produce earthquakes 

 of great energy during very recent geological periods ; and there is no 

 reason to suppose that these apparently slumbering causes may not at 

 intervals manifest themselves by producing visible changes upon the 

 face of the country. Its geological structure indicates that it is within 

 the great region of volcanoes and earthquakes, which embraces nearly 



all Western America. Tyson s Report on the Geology of California. 







CALIFORNIA GOLD MINING. 



FROM various statements published during the past year, we learn 

 that several successful attempts have been made, and are now in prog- 

 ress, to work the gold-bearing quartz of California in a regular and 

 systematic manner. The position and extent of the gold-bearing quartz 

 at Mariposa Creek, where mining operations have been commenced 

 under the direction of Messrs. Stockton and Aspinwall, are thus de- 

 scribed by Mr. Forrest Shepherd. He says : 



" The quartz vein varies from three to six feet in thickness, and runs 

 nearly E. and W. in walls of talcose slate. It has a slaty structure 

 similar to the neighbouring rock, and dips to the south at an angle of 

 about eight degress. A shaft has been sunk to the depth of twenty- 



