102 THE GEOLOGY OF ST. MARY's COUNTY 



jx'riod, it was again submerged, l.mt not to tlie same extent as in the 

 previous cycle, during the deposition of the Sunderland formation. 

 The subsidence, however, was sufficient to drown the rivers which 

 had opened up their valleys across the county and to transform these 

 into estuaries, so that a waterway extended across Calvert County 

 from what is now the mouth of Fishing Creek to the mouth of Hunting 

 Creek. Another waterway from the south ran from Drum Point south- 

 westward to what is now the head of the Hunting Creek estuary, and a 

 third extended from what is now the mouth of Parker Creek across the 

 divide to Battle Creek. Other streams of less importance were also trans- 

 formed into estuaries, so that the county presented a most irregular 

 shore line and the lower half of the region was transformed into a group 

 of small irregular islands. The subsidence at this time amounted to 

 about 90 feet. As the region remained at this level for some little 

 time, the waves along the shore had an opportunity to do considerable 

 erosive work and forced the shore lines back toward the rivers, widening 

 the valleys which had been previously opened during the erosive interval 

 which followed the uplift of the Sunderland formation. The material 

 which was derived from the wave erosion was deposited along the floor 

 of these estuaries, filling them in to a considerable extent and raising 

 them up to a higher level than that which they possessed when the 

 country was submerged at the beginning of the epoch. While this pro- 

 cess of sedimentation was still in progress, the country once more rose 

 above the level of the waves and permitted the streams to cut again in 

 their old valleys. This epoch of elevation was apparently a short one 

 for there was not enough time to enable the streams to completely re- 

 establish themselves throughout the entire length of their former valleys. 

 They had only partially begun the erosive work when the country was 

 once more submerged beneath the waves and the deposition of the Talbot 

 terrace was begun. At this time, the streams were once more transformed 

 into estuaries, but not to the extent which they were in the previous 

 Wicomico cycle of deposition. The land did not sink more than 45 feet 

 below its present altitude and remained there for only a short time when it 

 was once more raised and eroded. This epoch of elevation was the one 



