CHAPTER V. 



THE CONGLOMERATES AND LOWER CARBONIFEROUS FORMA- 

 TIONS OF THE APPALACHIAN PROVINCE. 



Below the Pennsylvania Coal Measure series there are several thou- 

 sand feet of Conglomerates, sandstones and shales, with occasional 

 beds of limestones, and in localities showing thin beds of coal, which 

 have been referred to the Lower Carboniferous. Thej' present such dif- 

 ferences in their stratigraphy in different localities that considerable 

 difficulty has been experienced in correlating their several members. 

 In general they represent the Mississippian series of the interior, and 

 in some of the limestones fossils have been found establishing closer 

 correlation. But they rarely show any marine fossils and their classi- 

 fication has been made almost entirely upon lithologic and strat- 

 igraphic grounds. The Conglomerate at the top has been correlated 

 with the Millstone grit and classified as the base of the Coal Measures. 

 The lower formations were called " Umbral " and "Vespertine v by the 

 early geologists of the Appalachian province, "Mauch Chunk" and 

 "Pocono" by the Second Geological Survey of Pennsylvania, and 

 M Greenbrier r and " Pocono," by Stevenson in 1888. 



The Second Geological Survey of Pennsylvania, besides the elabora- 

 tion of the Pennsylvania series of Coal Measures, did good service in 

 differentiating the formations immediately below, which were called in 

 H. D. Rogers's nomenclature, " Umbral and Vespertine (Nos. XI and X)." 



Mr. I. C. White also took a conspicuous part in this work. He was 

 the author of the volumes on Lawrence County, 1 on Mercer County, 2 and 

 on Susquehanna and Wayne Counties, 3 on Pike and Monroe Counties, 4 

 and on "The Geology of the Susquehanna River region, in the six 

 counties of Wyoming, Lackawanna, Luzerne, Columbia, Montour, and 

 Northumberland." 5 In these volumes, besides the detailed correlations 

 of the outcrops of the several townships, constituting the bulk of the 

 reports, there is the development of a systematic classification and 

 nomenclature for the geological formations of the regions surveyed, 

 which were chiefly of Lower Carboniferous and Upper Devonian age. 



1 Second Geol. Surv. of Pennsylvania, Rept of Progress. Q 2 . Report on Lawrence County, and spe- 

 cial report on correlation of the Pennsylvania and Ohio coal beds. By I. C White, 1879, pp. 336. 



1 Q s . Report on Mercer County. By I. C White, 1880, pp. 233. 



S G 6 . Report on Snsquebanna and Wayne Counties. By I. C White, pp. 243. 1881. 



4 G 6 . Report on Pike and Monroe Counties. By I. C.White. Report on the Delaware and Lehigh 

 Water gaps. By H.M. Chance, pp. 407. 1882. 



6 G 7 . Report on Wyoming, Lackawanna, Luzerne, Columbia, Montour, and Northumberland Coun- 

 ties, (i. e., the parts lying outside of the anthracite coal fields). By I. C White, pp. 464. 1883. 

 108 



