30 THE PHYSICAL FEATUKES OF PKINCE GEORGe's COUNTY 



Eocene beds which outcrop there. He also found similar fossils at 

 Collington. In 1895 Clark re-visited the Fort Washington region 

 and published his observations in a brief article in the Johns Hop- 

 kins University Circulars. He stated that the Upper Cretaceous 

 strata found there are principally of Matawan age, but Kavesink 

 and Eedbank deposits occur sparingly. In the same year he pre- 

 sented a paper before the Geological Society of America, in which 

 the Upper Cretaceous deposits of the entire State were discussed. 

 A map showing the distribution of the strata accompanied the article. 

 White in 1891, in a correlation bulletin of the United States Geo- 

 logical Survey, and Clark, in 1897, in Volume I of the Maryland 

 Geological Survey, summed up all existing knowledge concerning the 

 Upper Cretaceous formations of the State in which references were 

 made to Prince George's County localities. Darton in 1901, in the 

 Washington Folio, mapped the distribution of the Matawan and 

 Monmouth formations and briefly described the character -of the 

 deposits. Somewhat more detailed information covering a larger 

 portion of the county is contained in the Patuxent Folio by Shat- 

 tuck, Miller and Bibbins. The fossil plants, which occur princi- 

 pally in the Magothy formation, are described by Berry in several 

 papers, beginning with one published in 1906. 



The Eocene. — The literature relating to the Eocene strata of 

 Prince George's County is more extensive than that pertaining to 

 any of the other groups of formations represented within the County. 

 This is accounted for by the presence of excellently preserved fossils 

 in finely exposed strata at Upper Marlboro, along Piscataway Creek 

 and in the Fort Washington bluff. With few exceptions all of the 

 numerous articles refer either to the deposits found at these places 

 or to the fossils obtained from them. 



Pierce in 1826, Avas the first to mention the Eocene strata of 

 Prince George's County. He speaks of the exposures at Upper 

 Marlboro. In 1830 Conrad i^ublished his first paper dealing with 

 the fossils of this region. In this publication he described several 

 new species of fossils from Piscataway. This marked the beginning 

 of some very careful work which he continued for over thirty years. 

 Between 1830 and 1866 the same author published thirteen other 



