810 FLORAL ZONES ()F THE POTTSVILLE FOKMATIOX. 



Of these species, Pecopterix ■'^errulata and the two Cardiocarpa are, 

 in oeneval. charac-teristic of and ahiiost exc-hisivoly contined to the 

 Upper Lykens division in the Southern Anthracite field and to the 

 upper portion of the Pottsvillc formation in the })ituminous basins. 

 Lt-phJndendi'iDi clypcKtuut, also, is not o-onerally foiuid in beds below 

 the same division except in the region under consideration. Its typical 

 phase is developed near th(> l)ase of the Coal Measures. .The remain- 

 ing species of the florula. although rt^presented by material too frag- 

 mentary for satisfactory identihcation, appears to be allied to one 

 of the forms of Neiiropterk in the upper divisions of the Pottsville, 

 rather than with the small, Callipteridioid, narrow-pinnuled types of 

 the Lower Lykens division. Thus, from the composition and distri- 

 bution of the flora, it seems probable, notwithstanding the small 

 number of species, that the coal, which is here over 5 feet in thick- 

 ness, is situated in the Upper Lykens division of the formation. 



The geolog}' of this portion of the field is shown on mine sheet i, 

 Atlas Southern Anthracite Field, t*t. I. The structure of the east 

 end of the region is illustrated in section 1, cross-section sheet i of 

 the same atlas. The columnar section of the upper portion of the 

 formation as measured in the Hacklebarney tunnel, al)out .3 miles dis- 

 tant, shown on columnar-section sheet ii, will, perhaps, serve in a 

 general wa}' to indicate the sequence of terranes at the top of Mount 

 Pisgah. although the coal in question is not identified. If this coal is 

 referable to the Upper Lykens division of the formation, as the fos- 

 sils seems to indicate, we may conclude either that the Lower Lj^kens 

 division at the eastern point of the field is much thinner than elsewhere 

 or that the basin Avhich, as mapped by the State survey, extends nearly 

 to the level of the Central Railroad of New Jersey' along the Lehigh 

 River is deeper near its extremity than has generally l)een supposed. 



HORIZON OF THE LOWER LYKENS VALLEY COAL IN THE WEST- 

 ERN MIDDLE ANTHRACITE FIELD BETWEEN FRACKVILLE AND 

 SHAMOKIN. 



About I mile east of the Altamont No. 1 colliery the Pottsville for- 

 mation ])ridges the axis which forms the line of separation ])etw(HMi 

 the Southern Anthracite field and the "Western ]\Iiddlt> Anthracite field, 

 and plunges into the steep Mahanoy Basin east of jNIahanoy Plane. 



A. For a long distance to the west of Frackville no coal of the 

 Pottsville formation has been worked to any extent, but at the old 

 Gordon (Franklin) mine, in the "Western Middle Anthracite Held, about 

 4 miles northwest of the old slope at the Gordon plane, which is within 

 the north border of the Southern field, a coal designated on the 

 mine sheets of the riekU and in the Summary Final Report of the State 



lAtlns Western Middle Anthracite Field, I't. H. mine sheet v; columnnr-scction sheet ii; I't. Ill, cross- 

 section sheets v, vi, section 12. 



