Looks like a fine-grained sandstone with longitudinal ripple marks on a bedding plane, and partings (not fractures) along other bedding surfaces.
The structure of the Appalachians is such that sandstones tend to form the ridges, while shales and limestones form the valleys. So most of the rocks you find on ridges are sandstones, or quartzite rather since they are low-grade metamorphic rocks.
and I would say that it is very nearly in place as a natural outcrop. The capstone has moved slightly..