February 10, 1905.] 



SCIENCE. 



221 



well-shaped driimlin had beeu removed by 

 erosion, leaving an abnormally steep slope ; 

 deep transverse trenches at right angles to 

 their longer axes ; straight or curved 

 trenches extending from their summits 

 down their sides; irregular pits in their 

 normally smooth surfaces; and, in one in- 

 stance, a terrace-like shelf with a convex 

 longitudinal profile, parallel with the crest- 

 line of the drumlin on the side of which it 

 occurs. In the valleys between the drum- 

 lins there are several eskers. From the 

 evidence the conclusion is drawn that the 

 drumlins of the Menominee area were pro- 

 duced by ice erosion from a previously 

 deposited till sheet. 



The drumlins of central New York State 

 were the subject of a brief paper by Pro- 

 fessor H. L. Fairehild, of the University of 

 Rochester, who also summarized the more 

 important glacial problems in the state. 

 A third paper by Professor Fairehild took 

 up the thesis that the theory of erosion by 

 ice is a fallacy, in amplification of a paper 

 presented by him at the preceding annual 

 meeting of the society. The author gave 

 arguments for arriving at the conclusion 

 that deep ice-erosion of living rock has 

 never been proven, and that it is practically 

 impossible of accomplishment. In New 

 York State there seems to be positive proof 

 that there has been no effective excavation 

 by ice in the valleys of the Finger Lakes, 

 the field study thus sustaining the theoret- 

 ical consideration of the question. 



The stratigraphical section of the pro- 

 gram showed the largest number of titles 

 of papei-s offered and read. Professor 

 W. G. Miller, of Toronto University, dis- 

 cussed the pre-Cambrian rocks in the vicin- 

 ity of Lake Temiskaming, Ontario, not 

 only from a stratigraphical, but also from 

 an economic, point of view. The region in 

 question shows at the base a complex as- 

 semblage of igneoias rocks, including gran- 

 ite. Erosion of this complex has given 



rise to conglomerate and finer-grained 

 slate-like rocks. Afterwards ensued a sec- 

 ond period of erosion during which arkose 

 and quartzite were deposited on the sur- 

 face of the older two series. Finally each 

 of these three series is intersected by dykes 

 of pre-Paleozoic age. The second group 

 or series, the conglomerate and slate, is of 

 economic interest on account of the occur- 

 rence therein of fissure veins carrying im- 

 portant amounts of silver and of cobalt 

 and nickel ores and smaller quantities of 

 other ores. 



In a paper on the paleogeography of St. 

 Peter time. Dr. C. P. Berkey, of Columbia 

 University, showed by means of charts and 

 sections the probable varying distribution 

 of land and water during the formation of 

 the St. Peter sandstone of Minnesota. The 

 rock was interpreted as of marine origin 

 where early deposited. The region then 

 became a land area with the production of 

 sand-dune phenomena, after which there oc- 

 curred another period of submergence. In 

 the discussion which followed the reading 

 of the paper the fact was brought out by 

 Professor Gilbert van Ingen that rounded 

 sand grains are not necessarily an indica- 

 tion of arid conditions of deposition, since 

 they are found in coastal sand-dunes to- 

 day. Dr. Berkey 's second paper was upon 

 the stratigraphy of the Uinta Mountains 

 and announced the discovery of an erosion 

 interval in the section, which favored the 

 reference of the great basal Weber quartz- 

 ite to Cambric age, rather than to Carbonic, 

 as held by King, or to Devonic, as contend- 

 ed by Powell. 



Professor A. W. Grabau, of Columbia 

 University, in a paper on the relative areas 

 of the Oneida and Shawangunk conglom- 

 erates advanced the theory that these beds 

 represent different portions of a basal con- 

 glomerate in the transgressing Silurie sea. 

 In another paper. Professor Grabau dis- 

 cussed Helderberg seas and the interrela- 



