150 



LOWER EOCEISrE FLORAS OF SOUTHEASTERN NORTH AMERICA. 



It is not now and perhaps never will be ad- 

 visable to part with the terminology and con- 

 sequent ])erspective which has orginated in the 

 liistorical development of the Cenozoic geology 

 of southeastern North America. At the same 

 time the standard chi-onologic units should be 

 international and not provincial. In order, 

 therefore, to state the results of my study nf 

 the -American Tertiaiy floras in terms of general 

 imdei-standing, I have attempted correlations 

 with standard European sections, and as the 

 Eocene and Oligocene terranes of the Paris 

 Basin were not only the first to be elucidated 



different continents and by more exact corre- 

 lation between these remote regions. It is 

 obviously impossible to determine in wliich 

 areas certain types make their first or last 

 appearance if our chronology is inexact. This 

 is my main reason for attempting precise cor- 

 relation with European plant-bearing horizons. 

 The composition, habitat, and environment 

 of the Tertiary floras of southeastern North 

 America can be worked out by a careful study 

 of the prcscrvetl flora, but this is after all only 

 provmcial. ^\^uch are the endemic and which 

 the exotic types, whence they came and 



Figure U.— Skott-h map showing thn ar^a or Wilcox sedimt'ntation (solid blackj and the loialioii oi fossil floras with which that of the Wilcox 

 has IJi'iin compared. 1, Raton formation (ICnowlton); 2, Denver formation (ICnowlton): 3, Fort Union formation (Ivnowlton); 4, Ivenai 

 formation (Hollick); 5, West Greenland (Hucr); (i, Bolivia (Engelhardt); 6A, Chile (Engclhardt); 6B, Colombia, and Ecuador (Eng 'Ihardl i; 

 7, Southern England (Ettingshausen, Starkie Ciardncr): 8, Paris Basin (Watelet.Fritel); 9,Gelinden (Saporta and Marion) Tricude Ij-val 

 (ilarty); 10, Provence (Saporta); 11, Ha;ring (Ettingshausen); 12, Dalmatia (Ettingshausen); 13, Austria (Ettingshausen); 11, Bohemia 

 (Ettingshausen). 



but also because the nomenclature used is wliither they went, when they originated and 



highly pliilosophic and has already come to be when they became extinct — such questions can 



wi(U'lv accepted as the standard, I have en- only be answered by the broader study wliich 



deavored to make close comparisons with the includes the known Tertiary floras of the 



French etages. whole world. 



Most floral studies are provincial at first and In Professional Paper 84 I gave a brief ac- 



many are never further cleveloped. However, count of the more im|)ortant Eocene floras of 



a great variety of important and interesting Europe and enumerated tlie recorded species. 



questions regarding the origin, evolution, mi- The present work is so lengthy that it is not 



gration, and extinction of the plant types of worth wiiile to i-c))eat these enumerations, 



the Tertiary, which are in reality the most The areas where Tertiary floras have b(H>n 



important questions that a study of Tertiary found willi whicli the Wilcox can be coinptired 



floras can solve, can only be attacked 1)y very most pro(ilal)ly are shown on the accompany- 



exact comparisons between flie floras of the ing sketch map of tlie world (fig. 11). The 



