36 NEW YORK STATE MUSEUM j 



Theresa formation is only 50 to 75 feet thick and is overlaid by a ' 

 limestone formation, some 100 feet thick, which contains but little ' 

 interbedded sandstone and is quite fossiliferous. This seems to us 1 

 on the horizon of the upper portion of the Theresa of the sections i 

 north and west, and we therefore classify it as a member of the ' 

 Theresa formation. j 



The rock cuts along the Adirondack Railroad, northwest of Sara- ' 

 toga, together with quarries to the south of the railroad, furnish us 

 with the best section of this phase of the Theresa formation and i 

 of the Potsdam beneath. The section has already been published, 

 and is here reproduced.^ j 



FEET INCHES ' 



22 Rocks concealed between two railroad cuts; j 



boundary between Theresa and Hoyt limestone 

 member in the interval; thickness about 20 .... j 



21 Rotten, brown, calcareous sandstone; blue when i 



fresh 8 j 



20 Hard, vitreous, light colored sandstone, banded \ 



with narrow streaks of darker, calcareous . ] 



sandstone 2 4 



19 Thin bedded, blue, calcareous sandstone, weather- , 



ing brownish -. 9 j 



18 Blue black, oolitic dolomite, frequent rounded 



quartz grains, many small drusy cavities i 3 : 



17 Blue, calcareous sandstone, weathering light col- \ 



ored, upper portion shaly i 8 • 



16 Hard, light colored, vitreous sandstone i 6 | 



15 Thin bedded, calcareous sandstone, somewhat j 



oolitic, blue when fresh but rapidly weathering ^ 



brown, mottled and crumbly, many drusy cavi- ^ * 



ties with calcite and quartz crystals ; abundant s ■ 



trilobite fragments, the lowest zone of these I :^ 



so far discovered in the Saratoga region i 3 



14 Light colored, vitreous sandstone 2 5 ' 



13 Bluish, nodular, finely crystalline dolomite, with j 



a slight amount of calcite cement, shaly at base • ,. » 



and summit, frequent nodules of crystalline " ' 



calcite ; holds Lingulepis acuminata 2 3 j 



1 N. Y. State Mus. Bui. 140, p. ttt-I2. 



