68 



THE EOCEXE DEPOSITS OF MAEYLAXD 



Creek, Stafford county, Ya., and Popes Creek, Charles connty, Md. 

 Throughout this distance the blnffs afford a nearly complete sequence 

 of the several beds of the formations, -ndiile the fossils are numerous 

 and well-preserved. 



The full Potomac Eocene series is given in both generalized and local 

 columnar sections on Plates Y and YI. The former is made up chiefly 

 from the local sections afforded by the bluffs at Glymotit, Aquia Creek, 

 Potomac Creek, JSTanjemoy Creek, Woodstock, and Popes Creek, but con- 

 tains additional data obtained at a few points inland. 



The local sections are presented in columnar form on Plate YI, and 

 the numbering corresponds with that given at the head of the descrip- 

 tions of the sections which follow. The numbering of the zones in the 

 general section is the same as that in the local sections. The unnum- 

 bered zones are pre- or post-Eocene, as the case may be. 



Pleistocene. 



Eocene. 



Cretaceous. 



I. Section at Glymont, north of wharf and ravine. 

 Gravel and loam 



Feet. 

 20 



'1% < 



r Light green glanconitic sand, underlain by argillaceous 



sand, TTith few fossils (Zone 4) 10 



Indurated greensand (Zone 3) 1 



Greenish marl with numerous fossils including Ostrea com- 

 pressirostra, CrassateUites alaeforrnis, TurriteUa mortoyii, 

 Dosinopais lenticularis, Jleretrix ovuta var. pyga, etc. 



(Zone 2) [ 21 



Argillaceous glauconitic sand for the most part without 

 fossils, but containing indeterminate plant remains and 

 l_ molluscan casts at the base (Zone 1) 8 



Yariegated claj-s of the Potomac group. 



20 



Total 80 



Pleistocene. 



Eocene. 





II. Section two miles up Aquia Creek. 



Feet. 



Gravel and sand 



r 



; Indurated greensand (Zone 3) 1 



J Greensand with characteristic fossils (Zone 2) 1.5 



I Argillaceous sand more or less glauconitic without fossils 



I (Zone 1) IS 



L _ 



Total 41 



