106 PHYSIOGRAPHY AND GEOLOGY OF THE COASTAL PLAIN PROVINCE. 



II. Section right hank of Potofnac River three miles helow Potomac Creel;. 



Feet 

 Pleistocene Sand and gravel 2 



Eocene. Nanjemoy Potapaco Greenish-gray argillaceous sand (Zone 15).... 4 



Greenish-gray argillaceous sand with gypsum 



crystals (Zone 14) 5 



Light gray greensand with band containing Ven- 



ericardia potapacoensis (Zone 13) 4 



Greenish-gray argillaceous sand (Zone 12).... 10 

 Indurated greensand with Venericardia pota- 

 pacoensis ( Zone 11) 1 



Total 26 



III. Section right hanTc of Potomac River, center of bluff at Woodstock. 



Feet 

 Pleistocene Yellow and orange-colored sands and gravel .... 25 



Miocene. Calvert Diatomaceous earth with Miocene fossils 5 



Eocene. Nanjemoy Woodstock Argillaceous greensand (Zone 17 6 



Dark greensand more or less argillaceous with 

 Mitra potomacensis, Mesalia obruta, Strep- 

 sidura suh scalar ina, Turrit ella potomacensis, 

 Corbula oniscus, Meretrix subimpressa, Pro- 

 tocardia lenis, Pecten dalli, Ostrea sellae- 

 formis, Glycymeris idoneus and Leda cultelli- 

 formis ( Zone 16 ) 20 



Potapaco Greensand with Tornatellaea bella, Cylichna 

 venusta, Ringicula dalli, Venericardia potap- 

 acoensis and other forms (Zone 15) 6 



Total 62 



IV. Section two miles west of Passapatanzy, along hillside. 



Feet 



Pleistocene Gravel and loam 10 



Miocene. Calvert Diatomaceous earth 25 



Blue and drab clay with a few fossil impres- 

 sions 6 



Eocene. Nanjemoy Greensand, exposed 3 



Total 44 



V. Section left hank of Potomac River, three miles above Pope's Creek. 



Feet 

 Pleistocene Gravel and sand 3 



Eocene. Nanjemoy Potapaco Argillaceous greensand (Zone 15) 6 



Greensand with gypsum crystals (Zone 14) . . . 5 



Total 14 



