On the basis of a geological comparison of ophiolites, blueschists and related pre-Tertiary belts in Sakhalin and Hokkaido, a new tectonic correlation of the islands is proposed. The pre-Tertiary rocks in the West and Central (Langeri-Susunai) Sakhalin Zones are correlated to the Sorachi-Yero and Kamuikotan belts in Hokkaido. Those in the East Sakhalin Zone do not correlate exactly with Hokkaido but many peculiarities are similar to the Hidaka belt. Although tectonic nature and the location of the Tokoro belt are still debatable, various possibilities of its formation are discussed.
