92 THE EOCEXE DEPOSITS OF MARYLAND 



Piscataway sands Lelow. and the ]Marlburougli rock above — as represent- 

 ing a horizon nearly equal to that of the Thauet sands of England and 

 the Brachenx sands of the Paris Lasin, or of the British Bognor rock 

 (London clay). In either case they woiUd be near the base of the Eocene 

 series." 



Dr. Dall," in a recent article on " A Table of the ISTorth American 

 Tertiary Horizons, Correlated with one Another and with Those of 

 Western Europe, with Annotations," correlates the Maryland formations 

 with the Suessonian of Europe. As the writers of this report believe, 

 however, that the Eocene of Maryland represents more than the lower 

 Chickasawan of the Gulf, they would assign to the Maryland Eocene a 

 somewhat wider range in the European Eocene. It seems highly 

 probable that the Londonian and even the Parisian in part are also 

 represented. The few identical species in the two areas have a wide range 

 geologically, and are thus of little value for purposes of detailed corre- 

 lation. Other species may ultimately be found in common, but more 

 careful comparisons than have been made will be necessary to estab- 

 lish this fact. Until such investigations have been made the correlation 

 of the deposits on the two sides of the Atlantic can be at best only 

 provisional. 



' 18th Auu. Kept. U. S. Geol. Survey, pt. ii, 1S9.S, pp. 327-348. 



