152 THE COASTAL PLAINT FORMATIONS OF CECIL COUNTY 



to the Jurassic. The Patuxent formation is developed in a broad 

 belt extending across the county from the Delaware line to the 

 Susquehanna river with an average width of about 5 miles. Its 

 southern margin, where it passes beneath the overlying formations, 

 is approximately coincident with the north shore of Northeast River 

 as far as the town of Northeast, and from here to Iron Hill with the 

 line of the Philadelphia, Wilmington and Baltimore Railroad. The 

 northern border of the belt lies roughly parallel to the southern 

 and passes through Barksdale, Cherry Hill, Egg Hill, Bay View, 

 Theodore and "Woodlawm. Throughout this belt the Patuxent for- 

 mation is by no means continuously developed, but has suffered so 

 from stream erosion that it is present in irregular masses and isolated 

 outliers only. The formation has not only been removed from a 

 great territory to the north over which it formerly extended, but has 

 also been swept out of most of the stream channels which cross it. It 

 is thus restricted to the divides and is found on them with circuitous 

 and irregular outlines. The area possessing the greatest width is 

 found on the western end of the belt, extending from a mile northwest 

 of Woodlawn to the mouth of Furnace Creek with a width of 7 

 miles. The formation is laid down unconformably on the under- 

 lying crystalline rocks and unconformably beneath the deposits of 

 later age. It is overlain throughout a portion of this belt with out- 

 lying remnants of the Patapsco formation, the next younger member 

 of the Potomac group, and also by sands and gravels of the Lafayette 

 formation and the Columbia group. 



The materials making up the Patuxent formation are extremely 

 varied. They consist of variegated clay^ sand, gravel, ironstone and 

 conglomerate, both cross-bedded and horizontally stratified. These 

 materials are not regularly distributed throughout the formation in 

 well-defined and continuous beds, but alternate and change rapidly 

 the one into the other both horizontally and vertically. As a whole 

 the formation is predominantly sandy and bears an abundance of 

 water. The great development of drab clay, which is described in 

 the accompanying section, is a rather unusual occurrence of that 

 sort of material in this formation. 



