THE FIRST, OR SOUTHERN COAL-FIELD.
first of the lies on the south of the anthracite regions, and extends in an east-and-west direction from the Lehigh as its eastern extremity to a point near the Susquehanna as its western terminus. It is a long and narrow basin, or series of parallel basins, consisting of a number of long, slender, synclinal troughs and sharp, narrow, anticlinal ridges, which traverse the coal-field in echelon from south to north by the right flank. This general strike of the anticlinals is consistent through out the anthracite regions ; and, while the coal-fields themselves lie in the same form on the map, with a general direction from east to west, the axes of formation all point northeast and southwest.
The extreme length of the South coal-field is about 73 miles, with a mean breadth of two miles and a maximum of five miles. It commences on the Lehigh in a sharp, narrow point, and gradually widens towards its centre, which is about the location of Minersville. From this point it depreciates in size towards Tremont, where it is about three miles wide, and from thence again increases to the point of division, five miles west of Tremont, where the field is separated and forms two prongs, or long, slender extensions. The south fork preserves the general western direction, and extends about 27 miles froth the point of division, in the vicinity of Lor berry Creek, to a point near Dauphin on the Susquehanna. The north
fork projects in a northwestern direction, on a line with the axes of forma tion, or the anticlinals of the field generally. It is about 17 miles in length, from the vicinity of Rausch Creek to a point three miles west of Bear Gap, in Lykens Valley.
A distinct body of coal, known as the Mine Hill basin, but included in this field, lies along its northern edge in a central position : it is 14 miles long, with a maximum breadth of about half a mile.
The entire area of the coal-field is estimated at 146 square' miles, and has been divided by P. W. Sheafer, one of our prominent geologists and mining engineers, into the following districts and areas :— Compared with the Middle coal-field, the Southern field is one-third greater in extent ; but with the Northern coal-field, it is one-fourth less. The three principal coal-fields form an aggregate area of 435 square miles : consequently, this field constitutes about one-third of the area. The Lehigh basins, which are a detached group, have an aggregate area of 35 square miles; which swells the entire area of the anthracite regions to 470 square miles.