766 FLORAL ZONES OF THE POTTSYILLE FORMATION. 



beds in the western part of the field is well shown in the sections at 

 Lincoln/ Kalmia," and Likens/ Portions of the first two named are 

 reproduced in Pis. CLXXXIII and CLXXXTV of this report, in 

 illustration of the formation in the Lincoln mininy- reuion. 



CONGLOMERATIC NATURE OF THE COAL MEASURES. 



It may l)e remarked in this place that throughout the Southern 

 Anthracite field the Lower Coal Measures also are largelj^ conglom- 

 eratic. Frequently these conglomerates rival in size and rigidity 

 individual beds of the Pottsville formation itself. Illustrations of the 

 proportions of conglomeratic material, which in some cases constitutes 

 nearly a third or more of the section, are found in columnar-section 

 sheets i and vi, in Pts. I and II, respectively, of the Atlas of the 

 Southern Anthracite Field; or in the sections at the tunnels in Wood's 

 colliery and Dundas No. 6 colliery, at the north base of Sharp Moun- 

 tain, between Pottsville and Tremont, shown in columnar-section 

 sheet viii, Pt. IV of the Atlas. The same character is still better 

 presented in the regions north and west of Tremont, the sections of 

 which are given in columnar-section sheet x, Pt. IV B of the Atlas. 



THE LYKENS OR POTTSVILLE COALS. 



It will be observed that in the section of the Pottsville formation at 

 the gap south of Pottsville a number of thin coals are present, several 

 of them ha^^ng been prospected in the vicinity of the typical localit3^ 

 Coals are to be found in varying numbers in every complete section of 

 the formation, though in the neighborhood of the type section the^^ 

 have not proved to be of profitable thickness. However, to the north 

 of Pottsville. on Broad Mountain, and to the west, throughout the 

 Southern field, coals occur in greater development, especially locally, 

 and have been extensively mined. Reference to several detached or 

 somewhat isolated mines in those coals will again be made in connec- 

 tion with the consideration of the distribution of the fossil plarjts and 

 the correlation of the coals. These coals of the Pottsville formation, 

 which are commercially known as the "Lykens" coals, and which 

 comprise the "Lower lied Ash" groups of the Southern field, appear 

 to be best developed or most advantageously exploited in the districts 

 west of Tremont. including the Lincoln region and the Wiconisco 

 Basin. 



In the anthracite fields, as well as in other coal fields of the Appa- 

 lachian trough, the combustible of the Pottsville formation is generally 



>Atlns Southern Anthracite Field, Pt. IH, mine sheet xvii; Pt. IV B, columnar-section sheet xi; 

 Pt. V, cros.s-scftii>n sheet .wii, section 24. 



2Idem, Pt. in, mine sheets xxi and xxii; Pt. IV B, columnar-section sheet xi, columnar sections 10, 

 11, and 12; Pt. VI, cross-section .sheets xxi, section 29. 



3Idem, Pt. Ill, mine sheet xx; Pt. IV, columnar-section .sheet vii, columnar sections 9, 10, 11, and 

 12; Pt. VI, cross-section sheet xx. section 28. 



