WHITE.] POTTSYILLE FLORAS IN OTHER REGIONS. 819 



present near the Gladeville sandstones in the Estillville quadrangle,^ 

 Virginia-Tennessee region; also in the Breathitt formation in the 

 London quadrangle, Kentucky; and in the Fayette sandstone itself 

 near Zela, in the Nicholas quadrangle in ^^'est Virginia. The Mercer 

 coals of northwestern Pennsylvania are possibly near the same horizon. 



CAMPBELL LEDGE. NORTHERN ANTHRACITE FIELD. 



The dark plant-bearing shales which lie within a few feet~ of the 

 supposed representative of the Mauch Chunk (No. XI) in the very 

 thin section (56 feet, more or less) of the Pottsville formation at 

 Campbell Ledge, near Pittston, Pennsylvania, contain a large flora,'' 

 which can not be older than Lykens coal No. 1 or bed L, and which has 

 so much in common with l>eds M and N (Upper Intermediate division) 

 of the type section at Pottsville as to strongly argue for a reference to 

 the same time interval. 



The question of the equivalence in the southern and central Appa- 

 lachian regions of the Upper Intermediate division, including the upper- 

 most 3(»0 feet of the type section, involves a both complicated and 

 diflicult problem, which, on account of the great expansion of the ter- 

 ranes representing this period as we pass from Sutton in central West 

 Virginia southward, cati not be appropriately discussed without a care- 

 ful presentation of the accompanying paleontologic evidence. Omitting 

 all the details relating to this question, which will receive special 

 consideration in a later paper,* it may suffice to say that in the southern 

 Virginia region the time interval, which is represented by 250 to 300 

 feet of beds, consisting chiefly of the upper plexus of conglomerates, 

 between Lykens coal No. 1 or bed L and the Twin coal in the Southern 

 Anthracite field, appears, as indicated by the fossil plants, to measure 

 over 800 feet of strata on the Kanawha River. It includes the lower 

 half or ''group" of the Kanawha formation. Within the lower por- 

 tion of this interval, which is less argillaceous, there occurs a more 

 gradual transition from the flora at the top of the Sewanee zone, or 

 that of Lykens coal No. 1, to the typical flora of the Lower Kanawha 

 group. The flora first recognized in the Brookville and Clarion hori 

 zons of the Northern Bituminous basins, or coal A at Tamaqua and 

 the Twin seam in the Southern Anthracite field, does not appear in 

 the Kanawha region until later Kanawha time. In the lower portion 

 of the Kanawha formation the flora agrees exactly in characters with 

 that of the Lower Coal Measures of the British coal fields, or the 

 greater portion of the Westphalian in continental Europe.^ In this 



1 Geologic Atlas of the United States, folio 12. 



2 1. C. White, Rept. Geol. Survey of Pennsylvania. <;?, ji. 143. 

 »Lesquereux, Coal Flora, Vol. Ill, pp. 8.5.5-8.56. 



<Bull. Geol. Soc. Americ-a, Vol. XI, pp. 145-178. 

 6Loc. cit., p. 167. 



