210 abstracts: geology 



tions of the Carboniferous. The lowest rock (Cuyahoga shale) appears 

 in the bottom of the Allegheny Gorge ; the Burgoon and Pottsville sand- 

 stones outcrop along the valley sides, and the Allegheny and Conemaugh, 

 which consist of shale, sandstone, and limestone, with interbedded 

 coal and clay, appear higher in the hills. The dip is gently to the south 

 with modification by low folds. 



The principal streams are Allegheny and Clarion rivers and Redbank 

 Creek, and along these a much discussed system of high terraces and 

 abandoned valleys is well developed. 



The coal beds lie mainly in the Allegheny formation. The lower and 

 upper Clarion, lower Kittanning, and upper Freeport coals are the most 

 important. Oil and gas in great quantities have been found in sand- 

 stones of the upper part of the Devonian and lower part of the Carbon- 

 iferous. E. W. S. 



GEOLOGY. — Geology and mineral resources of the St. Louis Quadrangle, 

 Mo.-Ill. N. M. Fenneman. Bulletin U. S. Geological Survey 

 No. 438. Pp. 73, with maps, sections, and views. 1911. 



The hard rocks outcropping in the St. Louis quadrangle are all of 

 Carboniferous age and include the Osage, Merrimac, and Chester (?) 

 groups of the Mississippian, all of which have been further subdivided, 

 and the Pennsylvanian coal measures. Older rocks, including the Kin- 

 derhook formation (Mississippian) and part of the upper, Ordovician 

 have been reached by drilling. The Paleozoic rocks are unconform- 

 ably overlain by Lafayette gravel of Tertiary age. The Pleistocene 

 is represented by the Kansan and Illinoian drifts, by loess, and by gla- 

 cial outwash of the Wisconsin stage. The recent deposits of the region 

 include terrace gravels and the alluvial filling of river valleys. 



The Paleozoic strata dip in general north-northeasterly, the fall 

 being from 50 to 60 feet to the mile. A. H. Brooks. 



PROGRAMS AND ANNOUNCEMENTS 

 PHILOSOPHICAL SOCIETY 



699th Meeting, November 11, 1911, Cosmos Club at 8.15. 

 A. J. Lotka: Evolutions in discontinuous systems. 



