334 J- S. BRADLEY, JR. 



tion. With the exception of the rocks at Stanbridge, it is not known 

 to be represented in the Champlain Valley. 



OTHER EXPOSURES OF BEEKMANTOWN IN THE 

 CHAMPLAIN VALLEY 



In a section at Fort Ticonderoga, New York, Brainerd and Seely 

 report the presence of 75 feet of limestone with Ophileta compla- 

 nata which they correlate with their Division Di. They report the 

 presence of Division E with several undetermined species of Euom- 

 phalus, Lituites, Cyrtoceras, and Orthoceras. The strata between 

 the top and bottom of the Middle Beekmantown are apparently 

 unexposed here. 



At Thompson's Point, 28 miles north of Fort Ticonderoga, 

 Beekmantown strata occur, which probably belong to the Lower 

 and Middle divisions. 



At Providence Island, 24 miles north of Thompson's Point, 

 New York, 236 feet of largely magnesium Hmestone occurs which 

 probably belongs to the upper Middle Beekmantown. 



The type section one-half mile north of Beekmantown station 

 is very poorly exposed but carries the gastropod and cephalopod 

 fauna which appears to mark the upper Middle Beekmantown. 



Keith has recently brought to attention two formations from 

 northern Vermont which may have close relationship with the 

 Philipsburg strata to the north.^ Three miles N.E. of Burlington 

 occurs the Shelburne marble of 200 feet or more in thickness, 

 which occupies the same stratigraphic position as the Highgate 

 slate to the north. The Highgate slate has yielded fossils which 

 Walcott and Schuchert have determined as Upper Cambrian. It is 

 believed that the Shelburne marble is younger than the Highgate 

 slate, and that the disappearance of the Highgate southward was 

 more likely due to Upper Cambrian erosion than to non-deposition. 

 The formation is almost entirely of white marble and may be con- 

 temporeaneous with the lowest beds (Bi) of the Middle Beekman- 

 town at Philipsburg, which have a similar marbleized facies. 



The next succeeding formation described by Keith is the Willis- 

 ton limestone, which also outcrops near the town of Burlington. 



' Arthur Keith, Am. Jour, of Sci., Vol. V (1923), pp. 97-139. 



