510 



SCIENCE 



[N. S. Vol. XXXIV No. 877 



Carnegie Institute, wlio has been studying on 

 the spot for a considerable time, along with 

 Mr. Ellsworth Huntington, the desert condi- 

 tions of Arizona, will give a paper on Ameri- 

 can Deserts. Sir William Willeocks, whose 

 paper on Mesopotamia last session created so 

 much interest, will deal with his further re- 

 searches on the Garden of Eden and its res- 

 toration. Dr. Mackintosh Bell, late director 

 of the Geological Survey of New Zealand, has 

 promised a paper on an Unknown Corner of 

 South Island. Mr. Douglas Carruthers, who 

 has made extensive explorations in Central 

 Asia during the last 18 months, will give a 

 paper, probably in March, describing the re- 

 sults of those journeys. Mr. A. J. Sargent 

 will deal with the Commercial Geography of 

 the Tyne Basin, and Mr. P. A. Talbot with 

 the journeys in the central Soudan along with 

 Mrs. Talbot and Miss Olive MacLeod. In 

 January or February a course of three lec- 

 tures will be given in the afternoon on the 

 Desert of North Africa, by Captain H. G. 

 Lyons, E.E., F.E.S., formerly director of the 

 Egyptian Survey. The Christmas lectures 

 this session will be, on January 5, by Mr. 

 Julian Grande, the subject being " Amongst 

 the Alps " ; on January 8, by Mr. W. Herbert 

 Garrison, on " Our World Wide Empire " ; 

 and on January 11 " A Lady's Journeys in 

 the Central Sudan," by Miss Olive MacLeod. 

 Many glacial moraines contain particles of 

 gold, yet the metal is very rarely so abundant 

 as to make their treatment profitable. This is 

 due to the fact that running water has not had 

 opportunity to concentrate the precious metal 

 scoured by the glacier from the decomposed 

 fsurface of the mountains. In a short report, 

 however, just issued by the United States 

 Geological Survey, F. C. Schrader gives an 

 interesting account of gold-bearing ground 

 moraines at Kennedy Creek and Libby Creek, 

 Montana. The Kennedy Creek deposit, says 

 Mr. Schrader, is commonly known to mining 

 men who have examined it as ancient lake 

 gravel, but it seems plainly to be a subglaeial 

 or ice-laid deposit of till — a ground moraine. 

 The material is evidently derived from the 

 upland mountains on the northeast, whence it 



was scoured off the surface by the ice sheet, 

 shoved and dragged down the slopes, crushed, 

 ground and finally compressed beneath the 

 ponderous ice mass. The ice sheet probably 

 covered the basin with a thickness of a thou- 

 sand or more feet for a period of centuries. 

 A most unusual feature is the fact that this 

 glacial deposit does not seem to have been con- 

 centrated by later streams nor to have derived 

 its gold from preexisting placers. If this view 

 is correct there must occur in the mountains 

 or uplands to the northeast, in the path of the 

 ice that deposited the moraine, some rich gold- 

 bearing vein or bedrock area as yet undis- 

 covered. Tests made of the deposit in six 

 different shafts fairly well distributed over 

 about half a square mile in the southern part 

 of the basin show the gold content of the 

 deposits to range from 20 cents a cubic yard 

 near the surface to about $5 a cubic yard in 

 the bottom foot of gravel next to bedrock, 

 from which it is readily apparent that the 

 deposits contain considerable gold. By some 

 mining men the amount of gold present in the 

 basin has been estimated at $18,000,000. 

 From the data obtained in the present tests, 

 after reasonable allowance is made for bowl- 

 ders, which in the lower part of the section 

 constitute about 10 per cent, of the material, 

 the deposit in the southern part of the basin 

 seems to contain on the average about 80 cents 

 a cubic yard, including everything from the 

 surface down to bedrock, or about $4 a bedrock 

 yard. This would amount to about $17,360 

 an acre, or more than $5,500,000 for the Ken- 

 nedy placer portion of the area examined. 

 The estimate does not include the neck of the 

 deposit in the downstream outlet, which in 

 places attains a thickness of 80 feet or more 

 and is known to carry considerable gold. In 

 the basin as a whole, if gravel of this grade is 

 present throughout, there is probably more 

 than $11,000,000 worth of gold. The entire 

 district of which Kennedy Creek is a portion 

 is roughly estimated by Mr. Schrader to con- 

 tain about $100,000,000 worth of gold, much 

 of which, he states, to judge from the attention 

 the district is receiving, will probably be won 

 in the near future. 



