POTTSVILLE DISTRICT.
portion of the Southern coal-field is prominent as its central and most developed district; and here we find all the veins known to the anthracite formations of Pennsylvania in order and uniformity consistent with other regions. Here we find, also, the deepest basins, and all the peculiarities developed in other districts. It will be interesting, therefore, and perhaps useful, to illustrate in detail the varied formations and beds of coal, and compare the facts presented and illustrated in reference to other fields and districts with those we have now before us. We shall find more uniformity and consistency than might be expected from the many peculiarities and irregularities which we find around us. But even those irregularities or contortions, if we may call them so, will be found a uni formity, subject to the same causes and governed by the same laws. We shall also find an almost invariable order of disposition in the strata and general characteristic features governing the coal-beds.
It is stated by the former State geologist, who spent much time and patient study in the investigation of our anthracite fields, that the identity of the veins was an impossibility, and that but little similarity existed between the formations or measures of the respective fields. But we find this to be a mistake, arising from misconception and the want of that practical experience and judgment necessary to distinguish between theory and fact, and to reconcile and arrange facts and data drawn from a thousand sources. Had we adopted the views and opinions of all those from whom our information was obtained, we should have made the "confusion worse confounded." We have occasionally found much difficulty in reconciling the facts derived from different sources; but patient investigation generally brought order out of seeming contradiction and confusion; and we have no doubt but that the "Lehigh riddle" might be easily solved by careful investigation,—which, however, we are sorry to say, time will not permit.
Figure 74 illustrates the form ation and undulations of the coal measures from the Sharp Mountain, in the vicinity of Pottsville and Port Carbon, to the foot of Broad Mountain, at Repplier's Mammoth colliery, Wolf Creek, by the line of Mill Creek and St. Clair. But we
shall also apply the section to the line of Norwegian Creek by Oak Hill, Mount Laffee, and Coal castle.
The section is drawn looking east; the right-hand margin being the Sharp Mountain and the left the Broad Mountain. There are six large or prominent basins within the field and repre sented in this illustration; but there are perhaps as many rolls or subordinate undulations within the main ones which are not re presented in the figure. First, there appears to be a slight roll on the Gate Ridge anticlinal, h, the first anticlinal north of the Sharp Mountain; the second de veloped wave, or subordinate basin, is shown within the third main basin and north of the Mill Creek anticlinal, g; the fourth set of undulations are found in the furnace or shaft basin, and developed in Milne's Hickory colliery. Here several minor rolls have been developed, and these undulations are also manifest in the same basin at Oak Hill, in Brown's old Primrose water-levels, and in the workings of the Primrose and Orchard veins on the west branch of the Schuylkill, near Mine Hill Gap.
John's basin, at the south foot of the Mine Hill, is small and limited in length and breadth, and can scarcely be placed among the prominent basins; but we find its counterpart at Mount Laffee, and have, therefore, laid it down as the fifth basin, instead of assigning it as a temporary roll or undu lation.
The last subordinate basin we shall mention in this connection lies within the sixth or Mine Hill basin, and is known as the Jugular roll or " overthrow." We have mentioned, thus, a few of those small and subordinate undula tions before describing the principal basins, in order to prevent confusion in the statement, and enable our practical readers to follow us without noticing the future omission of those inferior basins.