MARYLAND GEOLOGICAL SURVEY 153 



The strike of the formation extends across the county from north- 

 east to southwest, and the normal clip is 60 feet per mile to the south- 

 east. An exception to this dip is found in the southwestern part 

 of the county, where the formation descends from an elevation of 

 440 feet near Woodlawn to tide in a distance of 6 miles, making 

 a dip of 74 feet per mile. This exceptionally high dip may possibly 

 be accounted for by movement along the " Fall line. 7 ' The thick- 

 ness of the formation shows a maximum at Elkton of 142 feet, which 

 was obtained by a well-boring at the City Pumping Station at that 

 place. 



The unusual thickness is believed to be caused by the materials 

 occupying a deep trough in the subjacent crystalline rocks. The 

 following section is the one obtained during the sinking of the well 

 at the Pumping Station. 



Section at Pumping Station Well, Elkton. 

 Formations. Feet. 



Talbot. Sandy Loam 4 



Patuxent. White plastic clay 10 



Coarse and fine sand, bearing lignite 32 



Coarse water-bearing gravel, with abundant transparent quartz 



pebbles and some white clay 3 



Fine white quartz sand 7 



Tough drab lignitic clay 85 



Water-bearing sand 1 



The estimated thickness of the formation in the vicinity of Poplar 

 Point is 60 feet. 



The fossils of the Patuxent formation in this county include ferns, 

 cycads, and conifers. ~No dicotyledons have, up to the present 

 time, been discovered in this formation. These plant remains have 

 largely been changed to lignite, and are found imbedded in the 

 stratified black clays in the Broad Creek depression. 



THE PATAPSCO FORMATION. 



The Patapsco formation is so called because of its typical develop- 

 ment along the Patapsco river near Baltimore. Its age, judging 

 from the plant remains, which have been found imbedded in its 



