MAKA'LAXn GEOLOGICAL SURVEY 25 



1S09-1S30. Although previous writers had casually referred to 

 the gravels, sands and rocks of the Coastal Plain, not until 1809 were 

 any strictly geological investigations published. Between 1809 and 

 1830 Maclure, who is sometimes called the "father of N'orth Ameri- 

 can geology," published several general articles on the geology of 

 Xorth America which served to stimulate investigation, while other 

 geologists noted the occurrence of minerals and fossils at various 

 localities. 



1SS0-1S80. In the next period investigations were confined 

 almost entirely to the study of the fossils which are so abundant in 

 the Cretaceous and Tertiary formations and to discussions of the age 

 of the fossiliferous deposits. While many erroneous conclusions were 

 reached by certain investigators, the work in general Avas carefully 

 done and formed the basis for subsequent investigations. The publi- 

 cations of Conrad stand out most prominently during this period. 

 Morton, Eailey and Leidy also made valuable contributions to the 

 geology of the Coastal Plain during this period while Ducatel, Alex- 

 ander and Tyson, although their work was not as important as that 

 of the investigators previously mentioned, advanced the knowledge 

 of the geology in no inconsiderable degree. These last three men 

 were principally concerned in the exploitation of the economic re- 

 sources of the region yet they made good use of the results obtained 

 by other workers and helped to spread the information. By 1880 

 nearly all of the broader divisions of the geological time scale had 

 been recognized and many tentative correlations had been made with 

 the geological formations of other regions. 



1S80-190S. Since 1880 many important publications have ap- 

 peared. The work of previous investigators has been critically ex- 

 amined ; definite lines of separation between the different formations 

 have been determined ; numerous subdivisions have been made as the 

 result of detailed stratigraphic and paleontologic work; and impor- 

 tant correlations have been established. In addition monographic 

 studies have been made on some of the formations rejiresented in the 

 region. The publications of Clark, McGee, Darton, Ward, Shattuck 

 and Martin are of primary importance during this period. 



