THE GREAT ALLEGHANY COAL-FIELD.
order to trace a connection between the anthracite and bituminous fields, we propose to devote a few pages to the connecting or intermediate basins or bodies of coal which exist as outlying patches along the north eastern margin of the Great Alleghany field. Those deposits are nume rous and frequently small, and are scattered through a great extent of country, along the head-waters of the Susquehanna, Juniata, and the Alleghany Rivers. We do not propose to notice them all. It would re quire more time and space than can be spared ; and, under present circum stances, such a description would be neither profitable nor interesting. We shall, therefore, confine ourselves to the northeastern basins, or those lying between the bituminous and anthracite fields.
Those small and detached bodies of coal all belong to the Great Alle ghany formations proper, and exist on the high western-dipping plateau peculiar to that great basin. They were originally part of one great and unbroken coal-field. Their present isolated condition is due to denudation ; and the deep valleys which separate them are invariably the beds of the present water-courses, cut into the soft red shale, but seldom below it.
Figure 114, from Taylor's Statistics of Coal, is so nearly correct that we introduce the original figure here, having purchased the right from Mrs. Taylor, not only to this engraving, but to all others which may be made use of from that work.
The relative distance between those basins is perhaps contracted. The intention is to convey an impression of the general character of those out lying patches, rather than their relative or exact positions. The left-hand
basin is that of Ralston, and the right the Blossburg basin. They are separated by the valley of Lycoming and Towanda, Creeks, which is over 1000 feet below the level of the coal. The basins of the "North Moun tain" and the Barclay coal-field occupy much the same position in regard to each other, and may be represented by the same illustration; though these latter formations are east of the former, and separated by a greater denuded space.
The detached coal-basins along the line of the Philadelphia & Erie Railroad, and the Lock Haven & Tyrone, are similar in character and general formation,—always existing on the tops of the mountains, and always separated by deep valleys cut in the red shale or the soft rocks which are subordinate to the conglomerate, while the conglomerate itself, which caps the mountains and holds the coal as it were in its hollows,— always in basin-shape,—is cut again into numerous smaller patches, as re presented in figure 114, by the smaller water-courses.
All this north and northeastern portion of the Great Alleghany forma tion was originally a vast level or slightly undulating plain, dipping gently to the west and southwest, and covered with an unbroken coal-field, which contained all the seams peculiar to our white-ash series, or below the " barren measures." In fact, it was part and parcel of the Great Alle ghany coal-field, as originally formed, and has only been separated from this great body by the forces of the rushing waters which have so mate rially changed the topographical features of Northeastern Pennsylvania.