MARYLAND GEOLOGICAL SURVEY 163 



worked Red Bank, and a short distance down the valley the forma- 

 tion itself appears, although poorly exposed. Across the stream from 

 the mill on Scotchman Creek is a very good exposure of Red Bank 

 showing its contact with the Navesink below. Here the formation 

 is a coarse, reddish-brown, case-hardened sand with little lenses and 

 pockets of gray-green glauconitic sand, which are usually surrounded 

 by a more or less developed layer of concretionary ironstone. Above 

 the dam the continuance of this deposit is slightly indicated in places, 

 and where the north and south road crosses a small tributary there 

 is an exposure of 15 feet. 



On the east bank of the first stream east of Scotchman Creek at 

 the road crossing there is a fine exposure of 25 feet of Red Bank. 

 It is a loose, brown sand unaffected by case-hardening. By far the 

 best exposure of the Red Bank sands is found at Bohemia Mills. 

 Here there is an exposure of 15 feet of Red Bank overlain with 5 feet 

 of Columbia loam and gravel. It is a reddish-brown, case-hardened 

 deposit containing hard pockets or lenses of grayish-green glanconitic 

 sand. The upper part is more firmly cemented than the lower. The 

 latter grades downward into a loose, greenish glauconite, containing 

 only a few ferruginous bands. Another extensive exposure, al- 

 though somewhat obscured, is found two miles south of Pivot Bridge. 

 The total section at the base is a brownish or a glauconitic sand, 

 while the top is reddish-brown, case-hardened sand belonging to the 

 Red Bank deposits. Unfortunately the contact between the two 

 beds is obscured, but it would seem that there is about 20 feet 

 of TvTavesink at the base of the cliff, and 35 feet of Red Bank above. 

 Beside these more instructive exposures, there are a large number of 

 lesser importance, which are frequently met with along the borders 

 of the Great and Little Bohemia creeks and their tributaries. With- 

 out going into details regarding these, it is sufficient to say that their 

 distribution indicates a great development of Red Bank in this re- 

 gion. Although fossils are occassionally discovered, they are not 

 well preserved, and are not numerous. They consist almost entirely 

 of marine mollusca. 



