The layers of quartzite are ordinarily very heavy, but the changing character of the original sediment is such as to make it easy to follow the layers. Some beds were composed of fine grains of quartz, mingled with clayey material, others of coarse grains with little clayey material, and others of pebbles so large as to pass into an unmistakable conglomerate. The pebbles of the conglomerate are mainly white quartz and red jasper. It is thus easy to discriminate the bedding of the series from the heavy jointing which occurs, cutting the bedding in various directions, and from a secondary cleavage and foliation which occurs in certain localities. From the general work of many geologists on dynamic action in folding, it is to be expected that the amount of movement necessary for accommodation between beds, and consequently the dynamic metamorphism resulting from shearing, would be less near the crown of the anticline than on the leg of the fold. That is, dynamic metamorphism ought not to be so extensive in the south range as in the north range. The facts described by Irving,[11] and those noted by me, fully agree with this anticipation. The central parts of the heavy, little inclined beds of the south range are largely indurated by simple enlargement. The pressure has not been sufficient to obliterate the cores, but has apparently granulated the exterior of some of the larger fragments, as in hand specimens the exteriors of the large blue quartz grains are white. Very generally the grains show slight wavy extinction. A few of them are distinctly cracked. The crevices thus formed and those in the interstices have been filled in large part by infiltrated silica, but their positions are plainly indicated by difference in extinction, by bubbles, by iron oxide, or by secondary mica which has taken advantage of the minute crevices. However, as described by Irving, between the heavy beds of quartzites are often layers, cut by a diagonal cleavage which dies out in passing into the thick beds. The layers showing cleavage sometimes pass into those showing the beginning of foliation, the rock then nearing a schist. In the centers of the schist zones, the schistosity approaches parallelism with the bedding, and in passing outward curves from this direction until it crosses the bedding at an angle, at the same time becoming less marked and grading into ordinary cleavage, which dies out in the quartzite. Upon the opposite side the transition is of the same character, but the curve is in the opposite direction.