162 PHYSIOGRAPHY AND GEOLOGY OF THE COASTAL PLAIIS^ PROVINCE. 



Feet 

 dita, Venus rileyi Ostrea sculpturata, Diplo- 

 donia clevatti {';), Glycrjmeris subovata, Dos- 

 inia acetabulum-, Pecten jeffersonius 14 



Gray sanch' and clayey marl. Contains Crepi- 

 dula, Venus, etc.. few and poorly preserved 14 



Blue sandy clay becoming marly and stained 

 brown by iron oxide. Contains Yoldia Icevis 

 (?), Cytherea sayana, Pandora crassidcns. 

 Spisula delumbis, Dosinia acetabulum, Ensis, 

 Scaphella, Dentalium dentate (?) 12 



Sandy marl with numerous shells that in some 

 portions are finely comminuted and cemented 

 together by calcium carbonate forming a 

 fragmentary rock; contains Pecten jefferson- 

 ius, Venus rileyi, Glycyineris subovata, Del- 

 phinula, Area incile. Ostrea compressirostra, 

 Ohama corticosa, Plicatula marginata, Raeta, 

 Pholadomya abrapta, Panopea reflexa, 

 Lucinae, Tellinae, Astarte limulata 27 



Blue sandy clay sometimes stained brown by 

 iron oxide; contains Tellinae, Spisula delum- 

 bis, Yoldia kevis. Pandora crassidois 5 



Sandy gray marl rendered somewhat hard by 

 the calcium carbonate from Crepidulae tliat 

 form the most of the bed; contains Crepidula 

 spinosa. Area centenaria, A. incile, Chama 

 corticosa, Ostrea compressirostra, Pecten 

 jeffersonius, Balanus proieus. . 13 



Soft yellowish-gray sandy marh Contains 

 Crepidula, though not so abundant as in 

 layers above or below 12 



Soft yellowish-gray sandy marl grading into 

 a blue clayey arenaceous marl; contains 

 Crepidula, Callocardia sayana, Turritella 

 alticosiata 12 



Total 119 



The above section was prepared by G. I). Harris, who made a careful 

 study of the Yorktown cliffs for Dr. Dall. The lowest member is exposed 

 about 3 miles below Yorktown and the highest outcrops near Indian Field 

 Creek. 



SECTIONS IN THE JAMES RIVER VALLEY. 



Because of the James Eiver being bordered by low land throughout a 

 large part of its lower course outcrops of Tertiary strata appear in few 

 places. However, in certain localities bluffs that are now being cut by the 

 waves of the estuary furnish admirable exposures for study and for the col- 

 lection of fossils. 



South of the James River in Nansemond County there are numerous 

 exposures, especially in the vicinity of Smithtield and Suffolk. 



