April 2, 1915] 



SCIENCE 



513 



as a memorial of her husband, and in March, 

 1914, a bill ivas introduced and passed in the leg- 

 islature accepting the gift and constituting the 

 American Scenic and Historic Preservation Society 

 the custodian. The park embraces the most pic- 

 turesque and geologically interesting part of the 

 Helderberg range in Albany County. 



The remarkable geologic formations to be seen 

 in this park include one of the finest exposures of 

 the Upper Silurian and Devonian strata in the 

 country, and offer classic types of several forma- 

 tions, as is shown by the designations "Helder- 

 berg limestone" and "Helderberg group"; the 

 rocks contain, a great number of characteristic 

 fossils, especially of marine forms. On the slope 

 appear Hudson shales, and flaggy sandstones of 

 the Hamilton formation crown Countryman Hill. 

 The deep amphitheater at Indian Ladder has been 

 worn out by the water of a small stream. 



There is now a small museum and library in the 

 park, and the Geological Survey has set up a 

 bench-mark. It is hoped that very soon the cot- 

 tage-building for the reception of guests will be 

 completed, so as to afford comfortable shelter for 

 visiting geologists who wish to study this Mecca 

 of geologists. The library would be glad to re- 

 ceive geological publications having any bearing 

 on the local conditions; such mail should be ad- 

 dressed to the curator of John Boyd Thaeher 

 Park, East Berne, New York. (By title only.) 



The Belief of our Pacific Coast: J. S. Dillee. 



The continental feature bordering the Pacific 

 coast of the United States is a mountain belt of 

 surpassing grandeur and composed in general of 

 two lines or ranges of mountain elevations with a 

 depression between. For the most part the two 

 lines of mountains appear to be parallel with each 

 other and the coast, the Sierra Nevada and the 

 Cascade Ranges on the east and the Coast Ranges, 

 including the Klamath Mountains of California 

 and Oregon and the Olympic Mountains of Wash- 

 ington on the west, from the Mexican line to that 

 of British Columbia. Cross folds connect the side 

 ranges and separate the great valley of California 

 from the Willamette Valley of Oregon. 



The Sierra Nevada is composed of folded sedi- 

 ments and igneous rocks of various ages from 

 Silurian to Jurassic, and faulted and tilted as one 

 great block with long gentle slope to the west and 

 steep slope to the east. 



The Cascade Range is essentially volcanic and 

 due mainly to volcanic upbuilding, though partly 

 to uplifting, from Mount Adams in Washington 



to Lassen Peak in California, but beyond these 

 limits the older crystalline rocks rise to the sur- 

 face. 



The Klamath Mountains are in large measure 

 like the Sierra Nevada in their rocks, although 

 more fossiliferous, but differ in structure, being 

 characterized by broadly curved thrust faults with 

 the overthrust into the concave curve and thus 

 toward the Pacific ocean. 



The coast ranges of California and Oregon are 

 composed almost wholly of Mesozoic and Tertiary 

 roeks. In California the coast range rocks are 

 greatly crushed and faulted, but in Oregon the 

 compression has been much less intense. 



At eight o'clock p.m., on December 29, the 

 society convened in the lecture hall of the Acad- 

 emy of Natural Sciences and listened to the 

 reading by Vice-president W. Lindgren of an ab- 

 stract of the address of the retiring president, 

 George P. Becker. The title of his address was 

 ' ' Isostasy and Radioactivity. ' ' 



In addition to the papers which were read at 

 the general sessions, the following papers were 

 presented in the sectional meetings of the society: 

 "Origin of the Red Beds of Western Wyo- 

 ming," by El. B. Branson. 



"Some New Points on the Origin of Dolo- 

 mites," by Francis M. Van Tuyl. 



"Range and Rhythmic Action of Sand-Blast 

 Erosion, from Studies in the Libyan Desert," by 

 William H. Hobbs (by title). 



"Corrasive Efficiency of Natural Sand-Blast," 

 by Charles Keyes (by title). 



"False Fault-Scarps of Desert Ranges," by 

 Charles Keyes (by title). 



"iStratigraphic Disturbance Through the Ohio 

 Valley Running from the Appalachian Plateau in 

 Pennsylvania to the Ozark Mountains in Mis- 

 souri," by James H. Gardner (by title). 



"Preliminary Paper on Recent Crustal Move- 

 ments in the Lake Erie Region, ' ' by Charles E. 

 Decker. 



"Quaternary Deformation in Southern Illinois 

 and Southeastern Missouri, ' ' by Eugene Wesley 

 Shaw (by title). 



' ' Old Shorelines of Mackinac Island and their 

 Relations to the Lake History, ' ' by Frank B. Tay- 

 lor. 



' ' Some Peculiarities of Glacial Erosion Near the 

 Margin of the Continental Glacier in Central Illi- 

 nois," by John L. Rich. 



"New Evidence for the Existence of Fixed 

 Anticyclones above Continental Glaciers," by 

 William Herbert Hobbs (by title). 



