THE HABITAT OF THE EURYPTEEIDA 



4. THE PITTSFORD SHALE 



This formation is typically developed in the western part of cen- 

 tral New York where, in the town of Pittsford, Monroe county, the 

 following section is shown (Sarle, 240, 1082): 





FEET 



INCHES 



1. Red shale 



6 



I 



I 



I 



I 



I 





2. Light gray, compact, fine-grained, dolomite, with im- 

 perfect conchoidal fracture, weathering light brown 

 to cream color 





3. Soft, gritty mud-rock, purple with bright red mottlings 



4. Dolomite like No. 2 



5. Purple shale with red mottlings 



6. Green shale 



3 



4 



11 



2 



7. Thin layer dolomite like No. 2 



8. Black shale, very compact, the base splitting unevenly; 



grading to olive-green shale in the upper part 



9. Dolomite like no. 2 



4 



10 

 10 



10. Black shale, with leaf of dolomite \ inch thick four 

 inches from its base 



2 



11. Dolomite like no. 2 



12. Soft, green, arenaceous mud-rock, occasionally becom- 



ing shaly; the lowest exposed rock of the cut 



2 

 8 



The eurypterid fauna occurs in the black shales, Nos. 8 and 10. 



A more complete section is shown in the wells of the region, from 

 which the exact location of the fossiliferous black shale beds is ascer- 

 tainable. The section carries the series down to the Lockport-Guelph 

 horizon. 



Salinan 





FEET 



INCHES 



1 . Red shale or marlite 



2. Hard, fine grained, yellowish, 



perfect conchoidal fracture. 



dolomite, 



having an im- 



IO 



2 



I 



3 

 3 



4 

 1 

 2 

 2 





3. Red shale 





4. Break estimated at 





5. Dolomite like No. 2 



6. Green shale or marlite 



7. Red shale 



8 



8. Break estimated at about 





9. Green shale 



5 







