Page:Report on the geology of the four counties, Union, Snyder, Mifflin and Juniata (IA reportongeologyo00dinv).pdf/189

Rh southern portion of the township, and everywhere largely cultivated.

Middle creek follows the course of this valley between the railroad and the limestone hill from the Franklin line on the west to a point north of Kremer, where it turns towards the southeast to cut across the valley and through the Ore sandstone ridge to the south. All the drainage of the township enters this stream on both sides and through it to the Susquehanna river.

The structure is quite similar to that of Penns township. The Shade mountain or Selinsgrove anticlinal lies a little south of the southern township line in Washington township, but its effect is to create north and northwest dips all through the township to the Jackson line, a short distance beyond which is the Northumberland synclinal axis.

The rock section exposed extends from the Clinton on the south to the Catskill on the north. From a point west of Middle creek, where the axis of Shade mountain crosses, there are two parallel ranges of hills which follow along the north base of the mountain all the way to and beyond Adamsburg. The outer ridge overlooking the valley of Middle creek is formed by the Ore sandstone and the inner ridge by the Iron sandstone and the lower Clinton shales, and both of them quite distinct and at some distance from the Medina crest of the main mountain.

The inner crest of these two subordinate ridges forms the southern township line to a large extent; and as the dip on each side of the axis is still very gentle, the ore associated with it has been largely mined along the Middle Creek—Washington township line. These openings will be described together with the geology of the latter township, where the greatest development has been made.

The lower Clinton shales between the Iron sandstone and the Ore sandstone crop in the belt three-fourths of a mile wide along the southern township line. They weather brown and yellow and upon a low dip of about 20° they have resisted erosion fairly well and make therefore high ground.