410 Scientific Intelligence. 



A large number of analyses of the drift of this region were 

 made and its lithological character carefully determined there- 

 from. The interesting result is found that 87 per cent of the 

 material is of local derivation, thus indicating a subglacial origin. 

 The surface bowlders are predominantly foreign and therefore 

 probably englacially transported. No essential lithological dif- 

 lerence was noted between the drift of terminal moraines, out- 

 wash, ground moraines and drumlins. i. b. 



17. Platinum in Black Sands from Placer Mines, David T. Day. 

 — A circular sent out by U. S. Geological Survey in March, 1905, 

 to some 8,000 placer miners, chiefly in the United States, has thus 

 far brought in some 828 samples of black sands ; these are largely 

 from the western states and territories, but also from British 

 Columbia, Central America and Mexico. Of these samples, 1 95 

 specimens were assayed for gold and platinum with tne result of 

 finding platinum in 72 of the specimens. Of these 72, 17 showed 

 only a trace and 14 an amount equal to tw T o ounces or more per 

 ton of concentrate. A sample from Junction City mining district, 

 Trinity Co., Cal., showed 25*8 oz. ; one from Oroville, Butte Co., 

 Cal., showed 27'45 ; and one from Riddle, Douglas Co., Oregon, 

 128*73 oz. In addition to these tests, 190 samples were examined 

 as to the minerals present with interesting results ; polycrase is 

 noted in sands from Idaho Co., Idaho, and columbite and tantalite 

 from Shoshone Co. Field work has also been carried on in the 

 collection and examination of sands of various placer deposits, as 

 also from bars in the Columbia river ; important results may be 

 anticipated from this thorough work. 



18. Cassiterite, a new cleavage, or perhaps parting law/ by 

 William E. Hidden (communicated). — Preliminary announce- 

 ment is hereby made of my late observation, at the Ross Tin 

 Mine, near Gaffneys, S. C, of a new cleavage (or "parting") in 

 cassiterite. This new cleavage is very common, almost perfect 

 and is parallel to e (101, 1-i). Very imperfect cleavages parallel 

 to s (111, 1) and m (110, I) were also noticed, those with s being 

 most common. 



Measurements of e A e (cleavage surfaces), with hand goni- 

 ometer, gave 133^°, while the required angle is 133° 32'. Faces 

 of the new cleavage up to four inches long and over two inches 

 wide were noticed, remarkably smooth and flat. They are very 

 characteristic of the locality. Twins parallel to the well-known 

 twinning plane (e, 101) were not uncommon. Some of these 

 were elongated with the s planes, making what seem to be pris- 

 matic planes, similar to sphene, etc. This new tin locality is 

 already credited with having produced about forty tons of cas- 

 siterite (yielding over 70$ metallic tin) and gives good promise 

 for the future. The associated minerals are albite, microcline (?), 

 amphibole, quartz, biotite, menaccanite, rutile, garnet and proba- 

 bly scapolite, monazite and eudialyte. 



