The Geological Society of America (GSA) performed a study to reconstruct the sea-level history in Chesapeake Bay.  As a part of that study the GSA arranged for borings to be taken on Taylors Island (see photos below). In 2013 Pat Neild allowed the borings to take place on his property and was in contact with the study's author, Benjamin D. DeJong. Although it is not mentioned in the study abstract, DeJong found that a branch of the Susquehanna River once passed under where Taylors Island is now.  The study makes a case that the local Chesapeake Bay region is subsiding. Here is a link to the study:
​https://www.geosociety.org/gsatoday/archive/25/8/article/i1052-5173-25-8-4.htm