MARYLAJvT^D GEOLOGICAL SUKVEY i O 



portion of the county to about 300 feet in the hills southeast of 

 Washington. 



Talbot Plain. — The Talbot plain borders the tide marshes and ex- 

 tends from sea level to an altitude of about 45 feet. It is present 

 throughout the county along the larger streams. In the valley of the 

 Patuxent Kiver this plain is characteristically developed. Here it 

 extends in an almost continuous belt from the southern margin of 

 the county to Hills Bridge, growing gradually narrower as it ascends 

 the streams and broken only by the shallow valleys of small streams 

 which cut across it in their course to Patuxent River. ISTorth of 

 Hills Bridge and on the western branch of , the Patuxent, the Talbot 

 plain is present only in scattered remnants. In the western portion 

 of the county this plain is Avell developed in the lower valleys of 

 Piscataway and Henson creeks, and occurs in an unbroken flat ex- 

 tending np the valley of Anacostia River as far as College Park. 

 The Talbot plain has been dissected by stream action less than any 

 of the other plains described below. 



THE DRAINAGE OF PKIXCE GEOKGe's COUXTY. 



The drainage of Prince George's County is comparatively simple, 

 as a result of the simple structure of the Coastal Plan formations 

 and the contiguity of the region to Chesapeake Bay. While prac- 

 tically all portions of the County are naturally drained there are 

 numerous small areas in which there is little surface drainage. Such 

 areas are most common on the wide stream divides near Brandy wine. 

 Numerous small upland swamps from which the surface water es- 

 cajjes only through percolation or evaporation occur in this vicinity. 

 In the northwestern portion of the county where the stream divides 

 are very narrow the only undrained regions are the tide-water 

 marshes already described. 



Stream Divides. — In the examination of the stream divides of 

 Prince George's County two peculiarities attract attention. The first 

 is their relative widths and the second their asymmetrical develop- 

 ment. In the southern portion of the County where the Lafayette 



