MARYLAND GEOLOGICAL SURVEY XXxix 



as the second Mediterranean of Austrian geologists and the faluns of 

 Tonrraine, and that the Marylandian was, at least in part, equivalent 

 to the first Mediterranean of Austrian geologists and fahms of Leognan 

 and Saucats. Three years later the same author published a map 

 showing the distribution of these formations along the Atlantic coast. 

 In 1888 Otto Meyer took exception to Heilprin's correlation and con- 

 clusions, and introduced the term Atlantic Group to embrace the Ter- 

 tiary of the Atlantic States, and Gulf Group for that of the Gulf 

 States. The Maryland Miocene lay wholly within the Atlantic group. 



Three years later Darton employed the term " Chesapeake Group " 

 to cover a portion of the Miocene and in the following year Dall and 

 Harris published their report on the Miocene deposits in the Correla- 

 tion Papers of the IT. S. Geological Survey, and used the term " Chesa- 

 peake Group '' to include the Miocene strata extending from Delaware 

 to Florida. These deposits were made during the Yorktown epoch of 

 Dana and the group included a large part of Heilprin's Marylandian, 

 Virginian and Carolinian. Two years later Harris, basing his work 

 on a study of the organic remains found in the Miocene, subdivided the 

 Miocene faunas of Mar3^1and into the Plum Point fauna, the Jones 

 Wharf fauna and the St. Mary's fauna. 



The following year Darton, by bringing together a large number of 

 well records throughout the Coastal Plain from New Jersey southward, 

 rendered a most important service to the study of the Miocene problem 

 in Maryland by suggesting the structure and extent of the beds through- 

 out the region. In his Fredericksburg folio, published in the same 

 year, he was the first one to express, on a contour map, the develop- 

 ment of the Miocene throughout a portion of southern Maryland and 

 eastern Virginia. The following year Dana admitted Harris's faunal 

 zones but still retained the term " Yorktown," to part of which he 

 assigned the Maryland beds. In 1896 Darton published a bulletin 

 under the auspices of the U. S. Geological Survey, in which he brought 

 together a large number of well records throughout the Coastal Plain. 

 He also published the Nomini folio, and carried forward the mapping 

 of the Miocene deposits which he had previously started in the Freder- 

 icksburg folio. 



