462 Scientific Intelligence. 



interrupted deposition. Both series are assigned to the upper 

 Keweenawan and are believed to have been deposited subaerially 

 in a basin formed by folding of earlier Keweenawan strata. The 

 contact of the Bayfield groups with the Middle Keweenawan 

 traps is described as a fault. The basin of Lake Superior at its 

 western end is interpreted as the result of differential erosion. 



H. E. G. 



7. State Geological Survey of Wyoming, Bulletin 4, Series 



B, The Salt Creek Oil Field, Natrona County ; by C. E. 

 Jamison, State Geologist. Pp. 75 ; 16 plates, map in pocket, 

 1913. — The Cretaceous formations — Dakota to Laramie — repre- 

 sented in central Wyoming have been described by Darton, 

 Stanton and Knowlton, and a paper on the Salt Creek Oil Field by 



C. H. Wegemann was published by the U. S. Geol. Surv., Bulle- 

 tin No. 452. Mr. Jamison, in the report under review, adds cer- 

 tain structural and petrographic detail, particularly with regard 

 to the oil-bearing sands. A description of the present stage of 

 development of the field, which has already produced 2,500,000 

 barrels, constitutes the larger part of the bulletin. h. e. g. 



8. State Geological and Biological Survey of South Dakota, 

 Bulletin No. 5, 1912, The Geography, Geology, and Biology of 

 South Central South Dakota ; by E. C. Perisho and S. S. 

 Yishee. Pp. 152, 44 plates, 5 maps, and geological chart. — 

 While of a reconnaissance nature, the report of Perisho and 

 Visher constitutes a praiseworthy contribution to our knowledge 

 of "bad lands " and sandhill in a region somewhat unique. The 

 topics treated, including climate, soil, topography, water supply, 

 ecology, etc., give the paper a geographic aspect and make it of 

 general interest. The reproduction of numerous photographs 

 increases its attractiveness in this regard. The geological chap- 

 ters contain those features most desirable in a preliminary report, 

 viz., recognition of the larger stratigraphic units, description of 

 the more common fossils, composition and areal distribution of 

 distinctive beds, combined with a discussion of the views of pre- 

 vious workers in the field. h. e. g. 



9. Brief Notices of some recently described Minerals. — Beta- 

 fite, Samiresite, Ampangabeite, Manandonite are names 

 given by A. Lacroix to new minerals from the remarkable pegma- 

 tite localities recently exploited in Madagascar. Of these beta- 

 fite from Ambolotora and samiresite from Samiresy are allied to 

 the Swedish species blomstrandite, which also occurs at Tonga- 

 feno. All these last species are isometric in crystallization and 

 contain uranium in considerable amount and are hence radio- 

 active ; other bases are present in small amount. For the 

 blomstrandite Pisani found 23-30 Nb 2 0., 28-50 Ta 2 5 , 10*87 Ti0 2 ; 

 for betafite, 34-80 Nb 2 5 , 18-30 Ti0 2 ; for samiresite, 45-80 Nb 2 5 , 

 3*70 Ta 2 5 , 6-70 Ti0 2 ; it also gave 7'35 PbO while the others 

 gave 4-00 and 3*45 CaO respectively. — Bidl. Soc. Min., xxxv, 

 84, 234, 1912. 



Ampangabeite occurs in large rectangular crystals of a brown 

 color ; specific gravity 4*29. Analysis gave 34*80 Nb 2 6 , 8'90 



