1951 年 24 巻 10 号 p. 337-343
It is generally believed that river piracy is a rare phenomenon in our mountainous country. In Jaapn, however, there are many upheaved peneplains where river piracy often occurs, and we have many examples of crustal movements which are the direct causes of river piracy. On account of these facts, various examples of river piracy are found in Japan, and these phenomena took place by way of surface streams and subterranean capture of surface streams, and faulting tilted block movement, tectonic line and selective erosion and so forth. In Japan, spill-overr is due mainly to volca-nic activity and river load. As regards regions, Chugoku and Abukuma districts attract our attention with their abundance of examples of river piracy and spill-over.