It looks similar to some I've seen listed as 16th or 17th century buckles from armor like the kind worn at Jamestown. Where did you find it, roughly? Not specifically, but, say, the closest town? I suppose it could be much later but it would be neat if it was early.
I don't know of any early colonial settlements in that area, so if it is an old buckle maybe it is an artifact from the Lost Colony that was traded among Native American tribes and ended up there. If it is much more recent, maybe it is part of horse tack. The first link is to a British database of small finds. Type in buckle and hit the search button. There are lots of double loop buckles illustrated. The second link is to the National Museum of American History; specifically to a page on military horses. There is a close-up of a bridle with similar buckles. Most of these buckles at these links seem to be made from brass.