308 ANNUAL OF SCIENTIFIC DISCOVERY. 



* 



was increasing. On transferring the solution to another basin, he found that 

 the crack presented a vein of gold ; the pure gold forming small nodular 

 masses along the iissure, both inside and out, and resembling veins of gold in 

 auriferous quartz rocks. Under the circumstances of the low temperature at 

 which the solution was being evaporated, the diluted state of the solution 

 still left unevaporated, and the difference of the appearance of the nodular 

 form of the gold vein from the usual appearance of the metallic gold obtained 

 by evaporation from such a solution, the author thought it worth while to 

 describe and exhibit the specimen. 



ON A POSSIBLE ORIGIN OF INCLINED STRATA. 



At the Albany meeting of the American Association, Mr. J. D. Whitney 

 gave a description of a remarkable instance of inclined stratification near 

 Lake George, where fine white sand containing small quartz pebbles has 

 been deposited over a considerable extent, and with a thickness of 25 feet 

 vertical, having a -dip of 30 degrees. This fact, thus established, that strata 

 may be deposited at a high angle, led to the development of a theory of the 

 formation and dip of the sandstones of the Connecticut valley and other 

 similar deposits on the Atlantic slope of the Appalachian chain. The main 

 point of the theory was this : that these beds of sandstone were originally 

 deposited in an inclined position in a basin of subsidence by currents of 

 water carrying detritus, which currents were produced by the subsidence 

 itself. If a fault originated in a valley, at one side or the other, and there 

 should be a subsidence on that side, a current of water would be produced, 

 of greater or less violence, which current would set across the valley and 

 carry with it the material abraded from the adjacent region, which would be 

 deposited in strata dipping, at a considerable angle, at right angles to the 

 line of direction of the fault, as in the Connecticut valley. According as the 

 subsidence was to the east or the west, the dip of the strata would be in the 

 opposite direction. Thus the origin of limited basins of sandstone, having a 

 dip transverse to the direction of the basin, would be fully explained by a 

 cause lying within the basin itself a phenomenon which had not as yet been 

 satisfactorily explained by geologists. 



ON THE MOUNTAIN CHAINS OF WESTERN AMERICA. 



At the Albany meeting of the American Association, "W. P. Blake, Esq., 

 in a paper on the Orography of the Western portion of the United States, 

 thus delineated and named the three chains of mountains, crossing the 

 country between the Mississippi and the Pacific ; the deductions being made 

 from a careful examination of all the recent Government surveys : First, the 

 Rocky Mountains, extending from the table land of Mexico to and beyond 

 the northern boundary. Second, the Sierra Nevada and its prolongations 

 north and south ; and third, the Great Basin range and other broken ranges 

 between the first and second groups. He then proceeded to describe these 

 chains. The length of the first, he said, was 1,400 miles, and its general 

 direction KN".W. and SS.E. The second chain is formed of many and 



