The weathering process in this instance would be likely to be temperature changes, especially changes above and below freezing, combined with moisture from precipitation.
New Hampshire is has a climate that goes well below freezing (say -25C) in the winter, and temperatures could rise as high as 35-40C degrees in the summer.
Any cracks formed can store precipittion whih will freeze on cold nights, and melt during the day. This alternate freezing and melting will encourage the penetration of moisture into the crack and also widen the crack when water freezes. However slow the process, in the passage of time, rocks will be loosened from the bedrock. Rock fragments that are not supported by gravity (those in cantilever positions) will be detached by gravity, resulting in collapse as illustrated in the photos.
