North Avenue, but beyond there it grows more distinctly a sandrock. It is seen in greatest elevation at what is now called Indian Rock, on which the tower in Ethan Allen Park is built. This rock is very nearly two hundred feet above the lake.

From the highest point of the park, and it is the highest eminence anywhere in the region for several miles in every direction, the great mass of sandrock slopes rapidly toward the east and ere long disappears. For a few miles to the east no rock is found, but after crossing the Interval it is seen in numerous places in Colchester, either as red or gray sandrock. North none is found until near Malletts Bay, at the Wakefield ledge, where marble, some of which is in the Albany State House, was quarried for a year or more.

Towards the city of Burlington, aside from the mass exposed at Rock Point, there are several smaller outcrops on the east face of the high bank along which North Avenue runs, but after passing the Institute road a little distance no more appears in the western part of Burlington until near "Oak Ledge."

Although, as has been noticed previously, the "overthrust" by which the old Cambrian beds have been shoved over the newer Utica shale, is plainly seen at several points about Malletts Bay, it is nowhere shown as finely as at Rock Point, at the place shown in Plate XLIV. At this point the rock rises according to the U. S. Topographical Survey nearly a hundred feet above the water of the lake. As the plates well show, the rock everywhere rises almost vertically from the water, but it does not reach its greatest height at the outer part, but a short distance inland.

These overthrusts are the result of the disturbance caused by what Logan many years ago recognized as "The Great Fault," whereby for many miles the rocks were broken and those on the east were first lifted hundreds of feet, probably, above those on the other side of the break and then shoved to the west over the newer layers. Whatever of newer layers were raised with the rest have long since been washed and weathered away so that now, as we see in the plate, Cambrian sandrock rests directly upon Utica shale.

South the same disturbance is found, though in somewhat different form, at Snake Mountain. The fault continues far beyond Vermont, crossing into eastern New York, but I do not know that there is seen overthrusting beyond Snake Mountain in Addison.

From Rock Point the shore is low and sandy until near Oak Ledge, a distance of over three miles. Here the sandrock again