Welcome Digger,
It's been pretty well established that a major tsunami hit the east coast 10-12 thousand years ago. Archeologists have found
the remains of habitats out on the continental shelf. Dating points from before and after that era can be tricky. The points
you show look like quartzite to me which indicates they were made post that event. The ones on the left show a distinct
lack of sophistication. This event would have killed most of the toolmakers, buried the sites where the preferred types
of media (chert, flint and types of volcanic glass) were mined and totally destroyed the trade network. The point on the
right is likely to be much later than the others as it shows, obviously, more sophistication. When relic hunting in the
tidewater and piedmont areas look for pieces of green glass. When the Europeans came here they brought wine in
glass bottles that became a major source of media for small tools and points.
Best wishes and good hunting.