158 THE COASTAL PLAIN FOK^IATIOXS OF CECIL COUNTY 



In Cecil county the beds of Upper Cretaceous age are not rich in 

 fossils. Remains of marine rnollusca have been discovered, but the 

 forms have not been as yet thoroughly collected and studied. They 

 are frequently in an advanced state of dissolution. 



THE MATAWAN EOR^IATIOX. 



The Matawan formation is the basal division of the Upper Creta- 

 ceous deposits of Maryland. It is so called from its great develop- 

 ment along the Matawan river of Xew Jersey. It is the oldest repre- 

 sentative of the Upper Cretaceous in Cecil county and is developed 

 along the Coastal Plain from Atlantic Highlands to the Potomac 

 river. It lies unconformably on the Raritan formation, the upper- 

 most member of the Potomac group, but is overlain conformably by 

 the Monmouth formation, the next younger member of the Upper 

 Cretaceous. In Cecil county it is found within a very narrow strip 

 of country, scarcely exceeding three miles in width, which extends 

 from the north bank of Bohemia River to Grove Point. Outside 

 of this district it is found in only one other locality, near the top 

 of Maulden Mountain. Although the Matawan undoubtedly forms 

 the substratum throughout the former area, still it is so largely 

 covered up by deposits of later age that good exposures are less com- 

 mon than might be expected. In only two localities does this form- 

 ation come prominently into view, namely, at Maulden Mountain and 

 Grove Point. At the former locality, on the western side of the 

 mountain, there is a steep sea-cliff, extending from the shore of Ches- 

 apeake Bay to a height of 170 feet, The lower 90 feet of this ex- 

 posure is composed of sands and clays belonging to the Potomac group. 

 Resting immediately and unconformably upon these beds are 60 

 feet of Matawan having a dusty green color. These are overlain in 

 turn with a bed of gravel and loam belonging to the Lafayette form- 

 ation. The Matawan beds of Maulden Mountain are slightly mica- 

 ceous and glauconitic. This latter characteristic is particularly evi- 

 dent near the center of the bed. Its upper portions show little or 

 no lamination, but at its base thin iron crusts appear which lie imme- 

 diately above a narrow band of dark to light gray clay, which has 

 been referred to the Raritan formation. 



