126 THE PLIOCENE AND PLEISTOCENE DEPOSITS OF MARYLAND 



that cypress, pine, beech, gum, locust, alder, huckleberry, sycamore, elm, 

 oak, hickory, and poplar were among the trees whicji composed the 

 forests. 



The Sunderland epoch was brought to a close by the elevation of the 

 region once more and the retreat of the Sunderland sea. The estuaries 

 gave place to rivers with rapid currents which extended their head waters 

 inland, sent tributaries back on to the divides, and began to rapidly tear 

 away the materials which the Sunderland sea had but a short time before 

 deposited. This epoch of uplift and erosion was not of such long dura- 

 tion as that which followed the Lafayette deposition. It was brought to 

 a close by the region sinking once more beneath the ocean and permitting 

 the Wicomico sea to advance as the Sunderland sea had done previously. 

 The various scenes enacted during this period were similar to those which 

 took place during the advance of the Sunderland sea. Chesapeake Bay, 

 which at first was separated from the ocean by an Eastern Shore barrier, 

 later on disappeared by the destruction and subsidence of this land mass 

 and the ocean broke once more unimpeded on the Western Shore. In the 

 northern part of this region as far south as the site of Baltimore, the 

 Wicomico sea broke near the base of the Piedmont, but south of this 

 point a great peninsula, covering the territory now occupied by Amie 

 Arundel, Calvert, Prince George's, Charles, and St. Mary's counties, car- 

 ried the Coastal Plain well out toward the southeast and about the border 

 and up the valleys of this peninsula, the waves of the Wicomico sea broke 

 and cut away the borders of the Sunderland formation and widened the 

 valleys. Grays Hill still stood out as an island in the Wicomico sea, but 

 Elk Neck appeared as a peninsula. The climatic conditions were similar 

 to those which held during Sunderland time and ice floes again drifted 

 down the rivers and scattered their contents of boulders and silt over the 

 sea bottom. The appearance of the region at this time is approximately 

 represented in Plate XXIX, where it will be seen that the depression of 

 the Coastal Plain did not much exceed 100 feet beneath the present stand 

 of the land. 



The Wicomico epoch was brought to a close by the elevation of the 

 region once more above water-level. The erosion which accompanied tin's 



