Page:Popular Science Monthly Volume 19.djvu/35

Rh William Johnson was conveyed from Schenectady to this locality on a litter, by some of the Indian braves of the Mohawk tribe, by whom he was evidently much loved and esteemed. It is highly probable that the High Rock was the only spring known to the Indians, and that Sir William was the first white man that ever visited it. In the long interval that has elapsed since the location of the High Rock was revealed, the number of springs developed has been very largely increased. With regard to the origin of these springs there are two theories advanced, both of which have able and zealous advocates; but, before presenting the claims of either of them to your consideration, it will be necessary to describe the geology of this vicinity, in order that they may be more fully comprehended. All of the rocks of this county are members of the oldest systems of geological formation, and are both metamorphic and sedimentary in their character; the granitic or Laurentian is of archæan origin, the remaining strata having been deposited during the Lower Silurian age. The accompanying map represents a transverse section of these formations, extending from the eastern portion to the higher altitudes located in a north-westerly direction from this village. The underlying rocks comprise first, the Laurentian; second, the Potsdam sandstone; third, the calciferous sand-rock; fourth, the Trenton limestone; and, fifth, the Utica, or black slate. At a very remote period of the past, the rocks comprising these various strata were subjected to some powerful natural force, which resulted in their fracture, dislocation, and the gradual upheaval of a large portion of them, producing at the point of disruption what is known to geologists as a fault. The position occupied by



the various strata is shown in Fig. 1: No. 1 indicates the Laurentian, the oldest of those belonging to the metamorphic system; No. 2, the Potsdam sandstone; No. 3, the calciferous sand-rock; No. 4, the