Febeuaby 9, 1900.] 



SCIENCE. 



229 



the Weisner formation, which has a thickness of 

 several thousand feet. The explanation offered 

 for these sinks is that the beds in which they 

 occur have been faulted over beds of limestone, 

 and the material which originally occupied the 

 depressions has fallen into underground chan- 

 nels through which it was carried off by flow- 

 ing water. 



(2) Mr. J. E. Spurr : ' Structure of the Basin 

 Ranges.' 



This paper describes the structure of many 

 hitherto unstudied ranges in southern Nevada. 

 The general structure is a series of open reg- 

 ular folds, with general north and south axes, 

 accompanied by occasional parallel and trans- 

 verse faults. Folding and faulting have gone 

 on continuously since the region was upheaved 

 at the close of the Jurassic. The present 

 mountains owe their forms chiefly to erosion, 

 which has been in progress, synchronously 

 with the folding and faulting, since Jurassic 

 time. The more common types are anticlinal 

 ridges and synclinal valleys. The mountains 

 are the compound result of erosion on rocks 

 upheaved by these compound movements. 

 F. L. Ransome, 

 David White, 



Secretaries. 



NEW TOKK ACADEMY OF SCIENCES. 

 SECTION OF GEOLOGY AND MINERALOGY. 



At the meeting on January 15, 1900, with 

 Mr. G. F. Kunz in the chair, there were 

 twenty persons present. 



A report was presented by Professor J. J. 

 Stevenson in behalf of the committee appointed 

 November 20, 1899, in reference to the death of 

 Sir William Dawson, of Montreal. On motion 

 by Professor D. S. Martin, the report was 

 adopted and recommended to the Council for 

 printing. 



The Chairman called attention to the coming 

 meeting this year, in Paris, of the Eighth Ses- 

 sion of the International Geological Congress, 

 described the proposed excursions, and sug- 

 gested the earnest cooperation of the Section by 

 delegates, contribution of papers and financial 

 aid. On motion by Professor J. F. Kemp, the 

 matter of the representation of the Academy at 



the International Congress was referred to the 

 Council for action. 



A paper was read by Professor F. B. Peck 

 ' On Serpentines and Talcs in the Vicinity of 

 Easton, Pennsylvania,' with abundant illustra- 

 tions by specimens of rocks, diagrams and lan- 

 tern views. 



In the subsequent discussion Professor Kemp 

 stated that, in the talc deposits on the west 

 side of the Adirondacks, described by Professor 

 Smyth, the derivation of the talc had been 

 attributed to the magnesium limestone or in- 

 trusion of a magnesium silicate rock. 



Professor Peck replied that he considered the 

 tremolite rock to be due to the alteration of a 

 siliceous dolomite ; the talc, possibly to the in- 

 terchange of silica from the pre-Cambrian 

 gneisses and magnesia from the adjacent dolo- 

 mite limestone. 



The serpentine and ' viridolite ' had indeed 

 been subjected to much shearing and fracture, 

 but had been solidly re-cemented, so that they 

 they could be quarried out in large blocks, free 

 from cracks — sometimes of twenty tons weight, 

 in the case of the ' viridolite. ' 



Professor J. J. Stevenson then discussed ' C. 

 E. Bertrand's Theory respecting the Origin of 

 Certain Coals.' 



Mr. F. E. Lloyd remarked that the cells of 

 algse, to whose accumulation Bertrand and 

 R6naud mainly attributed the formation of 

 these coals, are exceedingly delicate and often 

 mucilaginous. Those of sphagnum are much 

 thicker, solid and woody, and yet a large 

 quantity of this is required to produce much 

 deposit of carbonaceous matter in swamps. 



The Chairman inquired whether freezing or 

 the introduction of silty waters might cause the 

 precipitation of ulmic acid referred to by these 

 authors. 



Professor Stevenson stated that ulmic acid so 

 precipitated would tend to carry down sus- 

 pended matters and to clear the waters. 



A paper by Mr. H. Ries was then read, ' Note 

 on the Occurrence of Allanite in the Yosemite 

 Valley, California.' 



While in the Yosemite Valley in September, 

 1899, my attention was attracted by a black, 

 coaly-looking mineral in the pegmatite veins on 

 the northwestern side of the Valley. On closer 



