This is a scarf joint in granite. These foundational carved plinth stone joints are no longer as common as they once had been in Japan. These joints can, and did work well without such strapping for centuries in most applications and there is evidence that the straps can cause cracking in the stone by creating focussed stress points. The photo was taken 11 Dec 2011 by Bjorn Nelson, Bjorn@juankenobi.com