BEEKMANTOWN AND CHAZY FORMATIONS OF CHAM PLAIN BASIN 399 



B7, series of heavier, dark gray beds with abundant plates of 

 Palaeocystites. 



7a-io inches, barren; 7b-i4 inches, in lower 3 inches full of 

 trilobites ; 7C-3 feet 6 inches, heavy, crystalline bed, full of 

 Palaeocystites ; 7c^-24 inches, barren ; 7c^-8 inches, hard crystal- 

 line gray limestone with trilobites. 

 Bg, 5^ feet of dark shaly limestone, nearly bluish gray and very 

 fossiliferous, containing orthoceracones. 



Since we can do no better than base our future stratigraphic work 

 on the larger lithologic divisions recognized by Brainerd and Seely 

 in the Beekmantown formation at East Shoreham Vt. and in the 

 Chazy formation at Chazy village, we refer the fossils obtained 

 at other places than the Valcour shore provisionally to those 

 divisions. 



The Beekmantown beds have been divided by these authors 

 [1890, p. 2] into five divisions, termed A-E. 



Section at East Shoreham in ascending order 



Division A. Dark iron gray magnesian limestone, usually in beds one 

 or two feet in thickness more or less silicious, in some beds even ap- 

 proaching a sandstone. Fossils none. Thickness 310 feet. 



Division B. Dove colored limestone, intermingled with light gray 

 dolomite, in massive beds. Fossils : Orthoceras primigenium, 

 Cryptozoon steel i. Thickness 295 feet. 



Division C. In succession graj^, thin bedded, fine grained, calciferous 

 sandstone; magnesian limestone in thick beds, weathering drab; sand- 

 stones, sometimes pure and firm, but usually calciferous or dolomitic; 

 magnesian limestone like no. 2, frequently containing patches of black 

 chert. Fossils, none, except S c o 1 i t h u s m i n u t u s Wing. Thickness 

 350 feet. 



Division D. In succession blue limeston-e, in beds one or two feet thick, 

 breaking with a flinty fracture; the weathered surface with a rough, 

 curdled appearance; drab and brown magnesian limestone; sandy lime- 

 stone in thin beds; blue limestone in thin bands. Fossils: Ophileta 

 complanata, Maclurea affinis, Lituites eatoni, 

 Asaph us can alls and species of Cryptozoon, Bathyurus, Maclurea, 

 Murchisonia, Orthoceras, Cyrtoceras. Thickness 375 feet. 



Division E. Fine grained magnesian limestone in beds one or two feet 

 in thickness, weathering drab, yellowish or brown. Fossils: B u c a n i a 

 t r i p 1 a, Murchisonia c o n f u s a, Bathyurus e x t a n s ? var., 

 Primitia seelyi and species of Lingula, Maclurea?, Murchisonia, 

 Orthoceras, Bathyurus, Cheirurus? and encrinal columns. Thickness 470 

 feet. 



Brainerd and Seely as well as Gushing and the writer have 

 observed that also on the west side of Lake Champlain these greater 



