814 



SCIENCE. 



[N. S. Vol. XXIII. No. 595. 



well as of various accessions and additions to 

 the exhibition series. We note that the 

 ' Warren ' mastodon is said by Dr. Dwight to 

 be twelve feet high, but when properly mount- 

 ed it will be decidedly under ten. In regard 

 to the group of the crested cassique the de- 

 sirability of treating the bottom of the case 

 as if it were the ground may be questioned. 

 The impression will certainly be given, no 

 matter what the label says, that the nests are 

 close to the ground instead of high above it. 

 It may not look well to leave the bottom of 

 the case bare, but it is better to do this than 

 to give a wrong impression. 



SOCIETIES AND ACADEMIES. 

 THE GEOLOGICAL SOCIETY OF WASHINGTON. 



At the 179th meeting, April 11, 1906, 

 Major C. E. Button gave an outline of his 

 paper on ' Radioactivity and Volcanoes ' in 

 advance of its formal presentation before the 

 National Academy of Sciences. 



The Gold Field District, Nevada: Mr. F. L. 

 Eansome. 



Drainage of the Taylorsville Region, Cali- 

 fornia, during the Auriferous Oravel 

 Period: Mr. J. S. Dillek. 

 The drainage system of the Taylorsville 

 region, outlined by its deposits of auriferous 

 gravels, includes the broad valley of a river 

 heading south of Haskell Peak and flowing 

 north through the Downieville quadrangle for 

 nearly fifty miles across the fortieth parallel 

 by Mount Jura into a lake or estuarine water 

 body that covered the north end of that por- 

 tion of the Sierra Nevada. This ancient 

 watercourse is directly across the present 

 drainage, which is west into the North Fork 

 of Feather River. 



Though the exact head of the auriferous 

 gravel stream is in doubt, it originated in a 

 distinct mountain range near the source of 

 the Tuba and American Rivers. Its course 

 is clearly marked by numerous gravel deposits 

 well exposed by hydraulic mining. The bulk 

 of the material is gravel with some sand and 

 boulders which indicate, as pointed out by H. 

 W. Turner, a steeper grade for this stream 



than for those flowing down the west slope of 

 the Sierras. 



The delta deposit at the mouth of the 

 stream is nearly a dozen miles in length and 

 breadth. Where thickest it has 400 feet of 

 arkose sand beneath about 600 feet of gravel, 

 and possibly represents the whole of the gravel 

 period. Towards the top are rhyolitic tuffs 

 and andesitic breccias such as cover the earlier 

 gravels of the west slope of the range. Its 

 well-preserved flora is clearly that of the 

 auriferous gravel period. 



Since the gravel period that portion of the 

 range has been profoundly faulted and the 

 gravels displaced at several points to the ex- 

 tent of 2,000 feet. The fault along the Honey 

 Lake escarpment runs out into a fold over 

 which the gravel is lithified into solid con- 

 glomerate and some of the pebbles are faulted 

 and crushed in a remarkable manner. 



A Source of Hydrocarbons in the Ordovician: 



Mr. David White. 



It having been observed that the zinc de- 

 posits in southwestern Wisconsin are largely 

 coincident geographically with the distribution 

 of certain carbonaceous or ' oil ' shales ; the 

 examination of the latter was undertaken to 

 determine, if possible, the origin and mode of 

 occurrence of the hydrocarbons which seemed 

 to have influenced the ore deposition. 



The shales, known as Plattville shales, of 

 lower Ordovician (Black River?) age, lie at 

 the base of the Galena limestone, regarded by 

 Ulrich as Trenton. They occur in irregular 

 patches scattered over an area of nearly 2,000 

 square miles. The oil shales embrace thin 

 black shales and thicker chocolate to buff 

 shales mingled with calcareous sediments and 

 containing occasional marine invertebrate re- 

 mains. The approximate analysis is reported 

 to show a loss of volatile of 21 per cent, from 

 air-dried material, with an additional loss of 

 about 8 per cent, by incineration. The rock 

 yields a very porous light oil, 1.98 in specific- 

 gravity, giving gas bubbles in water. The 

 gas distilled from the oil shale gave Professor- 

 RoUin T. Chamberlain: H,S, 6.Y9; hydrocar- 

 bon vapors, 11.11; CO,, 18.12; heavy hydro- 

 carbons, 4.00; CO, 8.40; 0„ .26; CH., 35.98;. 



