146 D. WHITE — RELATIVE AGES OF KANAWHA-ALLEGHENY SERIES 



Page 



Motnotaxial relations of the Kanawha and Allegheny series 173 



< leneral correlations indicated by the fossil floras 17.". 



Reasons for assumed contemporaneity of the identical floras 174 



Evidence of the floras as to the isostatic movement in the southern Vir- 

 ginian region 1 77 



Introduction 



The two series or formations whose floras form the subject of this 

 paper are the Allegheny and the Kanawha series. The first, which is 

 typically developed in the Allegheny valley in western Pennsylvania, 

 comprises what has generally been known as the " Lower Productive Coal 

 Measures " in the northern bituminous fields. It lies between the Home- 

 wood sandstone, the upper member of the Pottsville formation, and the 

 Mahoning sandstone, a massive sandstone which forms the lower mem- 

 ber of the Conemaugh series or " Lower Barren Measures," consisting in 

 part of red shales. The thickness of the Allegheny series in western 

 Pennsylvania and northern West Virginia is usually about 300 feet. 



The Kanawha series is typically exposed along the Great Kanawha 

 river in southern West Virginia. Like the Alleghen}' series, this series, 

 which will be more fully described on a later page, lies, generally speak- 

 ing, between a sandstone group, including red shales, above and the great 

 arenaceous series below, representing the Pottsville. It, likewise, is com- 

 posed of shales, sandstones, limestones, etcetera, and is the most richly 

 productive division of the Coal Measures in the Kanawha region. The 

 Kanawha series develops a thickness of about 1,200 feet at its eastern 

 outcrop. 



On account of a similarity in the materials composing it, the similar 

 position of the series as a whole in the general lithologic sequence, 

 and the fact that the Allegheny series has been stratigraphically traced 

 with great detail as far as central West Virginia, the Kanawha series has 

 long been regarded as in toto the exact, though greatly expanded, equiv- 

 alent of the Allegheny series. Furthermore, although the stratigraphic 

 work in the geographic interval appears to have been somewhat frag- 

 mentary, even the much more numerous productive coals of the Kanawha 

 have in recent years been declared to be either exactly identical with the 

 respective Allegheny coals or, in view of the excessive number in the 

 Virginian section, as merety splits of the same. 



In view of these correlations, the paleontologist who examines the strati- 

 graphic occurrence and distribution of the fossil plants in the middle 

 Carboniferous along the Appalachian trough can not fail to be surprised 

 at the great differences between the floras of the several groups of the 



