30 , TRANSACTIONS OF THE [1888 



the red sands of the Cretaceous Lower Marl beds rise to the 

 surface in the region of Round Bay, and in contact with these 

 the fossiliferous ferruginous sandstones of the Eocene overlap 

 and mix their sand and broken fragments. A little farther 

 north of the same region, in the sandy belt adjoining the 

 Albirupian, the brown sandstone underlying the lowest bed of 

 the Cretaceous also comes to the surface, and here again the 

 Eocene fossiliferous brown sandstone runs in contact with the 

 similar rock and becomes confused with it. The same thing 

 appears to occur with the brown sandrock of the Columbian 

 formation. This latter pushes south and eastward from the 

 region of the primitive rocks and appears to blend with the 

 brown sandstone of the Eocene territory, or at least to mix 

 its sands with those derived from the latter. Notwithstanding 

 such obstructions, however, the northwest boundary of the 

 Eocene on the Eastern Shore may be said to begin at the Dela- 

 ware State line, near the northeast corner of Kent County, and 

 to extend west of southwest past Urieville and Fairlee to Chesa- 

 peake Bay, near Rock Hall. After crossing the bay it becomes 

 very conspicuous in the prominent red sandhills which rise in 

 Anne Arundel County, above the Cretaceous, east of Rock 

 Creek, and keeps on southwest across the Magothy, Severn, 

 South, and Patuxent rivers, all the way to the Potomac, as 

 before stated. 



As far as has been ascertained, the southeastern boundary of 

 this formation begins on the Eastern Shore near the head of 

 the Andover branch of' Chester river, next the Delaware line, 

 and extends, in an interrupted order, west of s(5uthwest past 

 Sudlersville, Churchill, and Centreville, and taking in Kent 

 Island, crosses to Chesapeake Bay. On the Western Shore it 

 starts at the mouth of West river, and following the trend of 

 the bay shore, keeps on through Calvert County to above Lower 

 Marlboro, and then passing across to the Potomac river near 

 Ludlow's Ferry, as before mentioned. 



This formation, in its fullest accessible extent across the 

 State of Maryland, may -be said to have a width of nearly 

 twelve miles, and this estimate does not include a few outlying 

 patches of the ferruginous sand and sandstone lying apparently 

 detached from the inner border of the main body of strata. 



