136 PHYSIOGRAPHY AND GEOLOGY OF THE COASTAL PLAIN PROVINCE. 



I. Section heloiv mill dam on MarricossicJc CreeTc one mile north of 



Bowling Green. 



Feet 



Miocene. Calvert Light greenish-gray sandy clay 10 



Dark green sandy clay containing casts, espec- 

 ially abundant near base, Turritella plebeia, 

 Venus, etc 8 



Total 18 



The top of the section is about on a level with the top of the dam. The 

 base is about 60 feet below the plain on which Bowling Green stands. 



II. Marricossicli Creek, at Travers mill, three and one-Jmlf miles north- 



east of Milford. 



Just below the east end of the dam there is a 5-foot exposure of green- 

 ish-gray clay containing casts of Turritella pleheia, Venus, Dosina, etc. 

 It belongs to the Calvert formation. In the compact clay in the bed of the 

 stream there are a few small potholes. 



III. Marricossich Creek, Smoot's mill. The dam is on the branch entering 



the creel' just above the mill. 



Just below the north end of the bridge 8 or 10 feet of greenish colored 

 clay are exposed, containing Miocene casts, principally Turritella plebeia^ 

 and some diatoms. The elevation is a little less than 100 feet above sea 

 level. Below the tail race at the mill similar materials are exposed. 



Miocene marl occurs four miles northwest of Walkerton on the farm 

 of G. Murdock, and was formerly dug. Specimens of the marl can 

 be seen about the old marl pit. The shells are so weathered that only 

 Plicatula, Pecten, Disdnisca, Ostrea, Chama, etc., could be recognized. 

 This marl appears in many small ravines on this and adjoining farms. 



In some ravines on the farm of T. M. Barefoot, three miles northeast 

 of Walkerton, great quantities of shell marl have been dug. The marl 

 is not being used at present because of the scarcity of labor. The marl, 

 as exposed, is about 25 feet in thickness. The upper portion is the same 

 bed as described on farm of G. Murdock, consisting of rotten shells form- 

 ing a lime sand in which Plicatula is unusually abundant. Beneath 

 €omes yellow and blue (where unweathered) sand in which there is a rather 

 varied fauna with shells preserved. 



