Page:The Journal of geology (IA journalofgeology11893univers).pdf/367

Fig. 1.Longitudinal section from Horse Hill to Barack M'Teth. Horizontal scale, one inch equals one mile; vertical scale, one-eighth inch equals five hundred feet.

erly, the local pitch^[1] varies greatly both in degree and direction, and is as frequently southerly as northerly, as indicated by the arrows on the map. At the south base of Tom's Hill the southerly pitch varies from 30° to 50°, and on the road cutting across the north foot of Barack M'Teth, beautiful corrugations in the Everett Schist pitch southward at as steep an angle as 50°. These corrugations are unsymmetrical, the west limbs being the shorter and steeper. The local variations in pitch are strikingly indicated on the map by those ridges of schist which are arranged linearly in the direction of the prevailing strike, being cut off from one another by limestone. The minor changes in pitch are further shown by variations in width of the ridges. Thus we find along the western margin of the area three marked undulations in the crest-line of an anticlinal of Riga Schist trending north-northeast. The northernmost is essentially the double undulation of Horse Hill and area No. 29, then follows the area northeast of Chapinville (14), and the area south of Chapinville Station (10). Fig. 1, which is a longitudinal section along this line, shows besides the three main undulations just mentioned, a number of secondary waves of more or less importance. In Fig. 2 (A) these curves of the crest-line may be better observed. The manner in which this anticlinal ridge disappears near the southern limit of the map is shown in Fig. 1 of Plate VII. The