MARYLAND GEOLOGICAL SURVEY XXXV 



at about this time, visited the Coastal Plain of Maryland and was so 

 impressed with its interesting geology and vast deposits of fossils, that, 

 on his return to Europe, he published an account of his experiences in 

 southern Maryland, and drew some interesting conclusions regarding 

 its geology. Finch in this book, which appeared in 1834, took excep- 

 tion to the classifications proposed by his predecessors. He believed 

 that the deposits included under the term " Alluvial " were contem- 

 poraneous with the Lower Secondary and Tertiary of Europe, Iceland, 

 Egypt and Hindoostan. He went further and divided Maclure's " Allu- 

 vial " up into Ferruginous Sand and Plastic Clay. He believed that 

 the Plastic Clay was Tertiary, and based his conclusions on the pres- 

 ence of amber, which he found entombed in it at Cape Sable, correlat- 

 ing it with the amber of the Baltic. He also assigned to the Plastic 

 Clay certain of the Indian kitchen-middens, which are found along 

 the shore of Chesapeake Bay, thus opening a controversy regarding 

 the age of these interesting deposits of oyster shells which did not reach 

 a final settlement until many years later. He believed that the mate- 

 rials composing his Ferruginous Sand and Plastic Clay were deposited 

 by a flood from the north or the northwest, agreeing somewhat closely 

 with Hayden in this particular. His correlations were based almost 

 entirely on lithologic distinctions, supported by a general similarity of 

 fossil forms. Xo critical study of the fossils was undertaken, however, 

 and few localities were given and no geologic boundaries whatever. It 

 is consequently impossible to ascertain where he intended to place the 

 formations which we now ascribe to the Miocene, and which he surely 

 visited. He might have thought them to belong to the London Clay, 

 together with those of the James and Rappahannock rivers, which he 

 also visited and ascribed to this formation, but it is more likely that 

 he placed them in the Plastic Clay. One thing, however, he perceived 

 very keenly — that the deposits in the Coastal Plain would with future 

 work be separated into many distinct formations. This prophecy has 

 since been fulfilled. During the same year Thomas Say described the 

 collection of fossil shells made by Finch, and among them appeared 

 many Maryland forms. This collection is preserved in the British 

 Museum. 



