^^HiTE] NOMENCLATURE OF THE COALS. 769 



called, the '"Big- bed,"' is about 115 feet below coal No. 3 in the Lincoln 

 tvinnels, though the interval is 140 feet in the large tunnel at Williams- 

 town. A thinner and less extensive coal, Lvkens No. 6, or the "little 

 bed," lies about 48 feet below No. 5 in the vicinity of the Lincoln mine, 

 though at Williamstown the interval is over 65 feet. None of the 

 upper Lvkens coals, Nos. 1-3. are worked in the Wiconisco Basin, 

 unless it be at Kohler's Gap, north of Brookside, where a coal, supposed 

 to be L3^kens bed No. 3, is dug- for local use. 



At the Brookside, Williamstown, and Short Mountain collieries 

 oidy the lower coals (Nos. 4, 5, and 6) are worked, except at Williams- 

 town, where a rather thin coal, the Zero bed, the thickness of which 

 is g-iven as 3 feet in the pu])lished section (columnar-section sheet 

 vii. Atlas Southern Anthracite Field, Ft. IV), has been developed at 

 37 feet 7 inches below coal No. 6. This bed, if present at all in the 

 Kalmia section, must be represented by only inches of coal, l)ut 5 

 feet 3 inches below the Lykens coal No. 0. The nomenclature of the 

 coals giA'en aliove is that employed by the Fhiladelphia and Reading- 

 Coal and Iron Company and adopted by the late State geological sur- 

 ve}'. In the vicinity of Lykens the coals were formerly numbered from 

 the base upward in an opposite direction, and thev are so designated 

 in Rogers's discussion of this lield in the Geology of Fennsylvania. 



The above statements of the intervals between the coals are given 

 as typical, without reference to the remarkable variation in the inter- 

 vals as ascertained })v the underground connections from mine to mine. 

 The matter of this variation, as well as the stratigraphic position of 

 the coals on Broad Mountain and in other portions of the field, will 

 be touched upon when considering the thickness of the Fottsville for- 

 mation and the evidence of the plants as to the correlation of the beds. 

 For information as to the thickness of the coals the reader is referred 

 to the State publications cited above, or to th(^ tvpical section repro- 

 duced in Fls. CLXXXIII and CLXXXIV. 



TIIP] TYPE PAIiEOBOTAXIC 8ECTIOX OF THE POTT8- 

 TILF^E FORMATIOX. 



FOSSIL-PLANT COLLECTIONS. 



In the Southern Anthracite field fossil plants have been collected 

 at 41 localities, from tlu> Fottsville formation, or from the roof of the 

 coal supposed to form the dividing line bet\v(>en the Fottsville forma- 

 tion and the overlying Froductive Coal ^Measures. These may ]>e 

 grouped as follows: 



1. Lower Lykens coals at Miller's drifts,' Big Run,' Wiconisco,'' Big 



1 PI. CLXXX, station 14. Atlas Southern Anthracite Field, Ft. Ill, mine sheet xx. 

 - I'l. CLXXX. station K5. Atlas Southern Anthracite Field. Pt. HI, mine sheet xx. 

 * PI. CLXXX, station 12. Atlas .Southern Anthracite Field, Pt. Ill, mine sheet xx. 

 20 CKOL. PT 2 4St 



