have been the other major source of data. However, many were drilled without adequate sampling and logging 

 and with minimal geologic study so it is not misleading to say that the Georgia Coastal Plain is almost 

 virgin material to the oil-driller's bit and that this area currently can be considered a relatively unexplored 

 province. The approximately 100 oil tests give a well density of about 1 for each 350 square miles. Many 

 of these wells are grouped so that the 34 oil tests logged by Herrick (1961) probably give a more repre- 

 sentative figure for use in a ratio — namely, 1 geologically studied oil well for each 1,000 square miles 

 of Coastal Plain. The 354 oil-test and water wells described in the well-log report give a ratio of one 

 well for every 100 square miles of Coastal Plain. Ratios such as these indicate that much more geologic 

 study of well samples will be needed for an adequate interpretation of Coastal Plain geology and that the 

 present report still allows for much additional work. Although this is a preliminary study with great dis- 

 tances separating the wells studied, much new information has been added to the knowledge of the subsur- 

 face geology and areas where additional work is needed have been delineated. 



This report summarizes paleontologic and stratigraphic work in the Coastal Plain of Georgia by the 

 senior author done intermittently over several years. The maps are based almost solely on the logs pre- 

 pared by him (Herrick, 1961). The maps, geologic sections, tables, and part of the text have been prepared 

 by the junior author after some restudy of the well-log data. Differences to be found between the data as 

 mapped herein and as published in the well-log report represent changes in interpretation. 



The maps and sections (see fig. 1 inside back cover) are based on the published logs of 354 wells in 

 the Coastal Plain of Georgia (Herrick, 1961). Because these logs have all been made by the senior author, 

 they represent a uniform considered treatment, a balance often difficult to achieve when synthesizing data 

 from many different sources. Therefore, with the wealth of new data, a completely fresh interpretation 

 seemed needed. A major exception in this policy is the area along the Georgia-Florida line where the 

 new maps were made to agree with the published literature: The thickness of the Miocene was reconciled 

 with that for Florida by Vernon (1951) ; the top of the Ocala was reconciled with data given in Black and 

 Brown (1951) and Meyer (1963); and the thickness of the Ocala tied to that given by Puri (1957). 



Paul L. and Esther R. Applin kindly furnished picks on the top of the Lower Cretaceous(?) Series 

 in the following wells: Colquitt 170, Early 121, and Echols 189; also from discussions with them revisions 

 of the Lower Cretaceous(?) in the well-log report were made in Liberty 363, Mitchell 109, Seminole 

 187, and Wayne 52. Unpublished lithologic logs by the late Vaux Owen, Jr., furnished formational tops 

 in the following wells: Sumter 281 and Sumter 296. Supplementary data on oil tests in Georgia were 

 taken from Hurst (1960). 



The foraminiferal names in the faunal lists of this report are mainly those as given in the well-log 

 report. The authors are cognizant that many of the names are not in accordance with recent generic 

 revisions. Examples include Epistomina caracolla which is now Hoglundina caracolla: Rotalia mexicana 

 var. mecatepecensis , which has also been called Neorotalia mecatepecensis (E.R. Applin, 1960, p. B208) 

 and Streblus mexicanus mecatepecensis (Cole and Applin, 1961, p. 127); many of the species of Cibicides 

 that now would be put in Cibicidina; and many of the species of Discorbis that could be regrouped under 

 Rosalina , Neoconorbina , and Rotorbinella . Nomenclatural changes such as these would be desirable 

 mainly for those concerned with taxonomic usage. However, for the many who are concerned with check- 

 ing their finds against the plates and descriptions as contained in paleontological publications, the use 

 of the older established names seems highly desirable. Because the names as given are generally those 

 found with the published plates, comparisons can be made far more readily than if the "up-to-date" names 

 had been used. 



Previous Work 



The interpretations in this report represent a fresh look at the stratigraphy, paleontology, and struc- 

 ture of the Coastal Plain in Georgia. Although the previous work has not been used directly, it has been 

 examined. Because the pertinent geologic literature on the area is synthesized by Murray (1961) and is 

 summarized by LeGrand (1961), the authors believe that any extensive review of the literature is un- 

 necessary in this report. The review of the literature on the Coastal Plain of Georgia is condensed into 

 two tables: one listing published subsurface geologic maps; the other listing published geologic sec- 

 tions. Also, in the discussion of the stratigraphy, pertinent paleontologic papers are cited. 



The subsurface maps in table 1 include those of the entire Georgia Coastal Plain as well as those of 

 individual counties. To facilitate use of the table, the maps generally are listed by geologic age of the 

 top or thickness of the unit mapped. Where titles mentioned base of a unit, this was altered to indicate 

 the top of the next lower unit. The list is restricted to original contributions and does not include maps 

 that are copied from previous publications. 



The geologic sections pertaining to the Georgia Coastal Plain (see table 2) are listed by author. To 



