.618 PROCEEDINGS OE WASHINGTON MEETING. 



13. Cambrian sandstone overlying Utica slate, which is not visible in this view, bav- 



ins; dipped out of sight. Lone Rock point, just north of Burlington, Vermont. 

 July, 1889. 



14. Au Sable chasm in Potsdam quartzite near Lake Champlain, New York. July, 



1889. 1st view. 



15. The same. 2d view. 



16. The same. 3d view. 



17. The Adirondacks, looking eastward from the summit of Mount Marcv. July, 



1889. 



18. Portage sandstone at Enfield gorge, near Ithaca, New York. Photographed by 



V.>. Marsters. 1890. 



19. Section of Portage shalv sandstone at the Buttermilk falls, near Ithaca, New 



York. Photographed by V. F. Marsters. 1890. 



20. Vertical schists, quartzites, etc., with trap dikes at Bald cliff, Maine. Photo- 



graphed by Harris Kennedy, 1888. Size, 6J x 8J inches. 



21. Schists and dikes at Kennebunkport, Maine. Photographed bv Harris Kennedy, 



1888. Size, 6^ x 8 J inches. (Amer. Geol., vol. V, 1890, p'. 129.) 



The United States Geological Survey, through the Director, Major J. W. Powell, 

 has contributed 269 photographs. These bear numbers from 22 to 290, inclusive, and 

 have been classified. Prices are stated at close of list. 



STRUCTURAL FEATURES OF ROCKS. 



Folds. 



22. Anticlinal in Levis terrane, on roadside leading up the bluff above Levis railway 



station. Province of Quebec, Canada. Size, 6x8 inches. Photographed by 

 C. D. Walcott, 1889. 



23. Southern shore of St. Lawrence river, 9 miles below Quebec, Canada. Plication 



of shales and sandstones of Sillery terrane. Size, 6x8 inches. Photographed 

 ' by C. D. Walcott, 1889. 



24. Anticlinal fold in Sillery shales and sandstones, 9 miles below Quebec, Canada, 



on southern shore of St. Lawrence river. Size, 6x8 inches. Photographed 

 by C. D. Walcott, 1889. 



25. Section of anticlinal ridge in railway cut one mile east of Dunkirk, New York. 



The rock is a black shale of Devonian age. The anticlinal structure was im- 

 posed after the retreat of the Pleistocene ice sheet. Size, 4 x 4| inches. Pho- 

 tographed by G. K. Gilbert, 1886. 



26. Arched strata on Chesapeake and Ohio canal, probably near Hancock, West Vir- 



ginia. Size, 8 X 10 inches. Photographed by H. R. Geiger, 1886. 



27. Fold in brown sandstone on Chesapealce and Ohio canal, 2 miles above Hancock, 



West Virginia. Size, 8 x 10 inches. Photographed by H. R. Geiger, 1886. 



Faults. 



28. Fault in sandstone and shale of the Newark system, Bogan cut, near Wades- 



borough, North Carolina. Hade toward the west. Size, 8 x 10 inches. Pho- 

 tographed by I. C. Russell, 1885. 



29. Fault between Archean gneiss and Trenton limestone and Utica shale, just south 



of Montmorenc}^ falls, Canada. Size, 8 x 10 inches. Photographed by C. D. 

 Walcott, 1889. 



30. Contact of rocks of lower Cambrian and lower Ordovician age, on the line of the 



great fault, about 2J miles northeast of Highgate springs, Vermont, Size, 6 x 

 8 inches. Photographed by C. D. Walcott, 1889. 



