38 THE PHYSICAL FEATURES OF ST. MART's COUNTY 



The first paper of importance was published b.y William Maclure in 

 1809. Althoixgh this contribution dealt in a broad way with the geology 

 of the United States, yet it shed considerable light on St. Mary's County. 

 He included the entire Coastal Plain of Maryland in one formation, the 

 " Alluvial," and so represented it on a geologic map. He also described 

 the unconsolidated Coastal Plain deposits from Long Island southward, 

 indicated the boundaries of the Alluvial formation and noted the pres- 

 ence of fossils. This paper was reprinted in substance in various maga- 

 zines in 1811, 1817, 1818, and 1826. Maclure's views seem to have 

 attracted considerable attention at first, for in 1820 Hayden incorpo- 

 rated them in his " Geological Essays " and attempted to establish the 

 theory that the Alluvial was deposited by a great flood which came down 

 from the north and crossed North America from northeast to southwest. 

 The following year Thomas Nuttall referred the Coastal Plain deposits 

 to the Second Calcareous formation of Europe, pointed out the fact that 

 it occupied the country east of the primitive and transition formations 

 of the Piedmont Plateau, and fixed Annapolis as about its northern limit. 



The next year, 1822, Parker Cleaveland brought out his treatise on 

 Mineralogy. In this interesting volume he reproduced Maclure's map 

 and recorded the occurrence of selenite crystals in the Alluvial soil on 

 the St. Mary's bank of the Patuxent Eiver. He probably had in mind 

 the locality directly opposite Solomons Island. 



Professor John Finch, an Englishman, who was travelling in America 

 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. Previously, in an article which appeared in 1824, he took ex- 

 ception to the classifications proposed by his predecessors. He believed 

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

 neous with the Lower Secondary and Tertiary of Europe, Iceland, Egypt, 

 and Hindoostan. He went farther and divided Maclure's " Alluvial " 

 up into Ferruginous Sand and Plastic Clay. He believed that the Plastic 

 Clay was Tertiary, and based his conclusions on the presence of amber. 



