Nd model ages using depleted mantle (TDM) values for the sedimentary rocks in the Inner Zone of the SW Japan and western area of Tanakura Tectonic Line in the NE Japan allow classification into five categories: 2.6-2.45, 2.3-2.05, 1.9-1.55, 1.45-1.25, and 1.2-0.85 Ga. The provenance of each terrane/belt/district is interpreted on the basis of the TDMs, Sm-147/Nd-144 vs. Nd-143/Nd-144 relation, Nd isotopic evolution of the source rocks in East China and U-Pb zircon ages. The provenance of 2.6-1.8 Ga rocks, which are reported from Hida-Oki and Renge belts and Kamiaso conglomerates, is inferred to be the Sino-Korean Craton (SKC). The 2.3-1.55 Ga rocks, mostly from Ryoke, Mino and Ashio belts, are originally related with the SKC and/or Yangtze Craton (YC). The provenances of the sedimentary rocks with 1.45-0.85 Ga, from the Suo belt, Higo and some districts in the Mino and Ashio belts, are different from the SKC and YC. Especially, the Higo with 1.2-0.85 Ga is considered as a fragment of collision zone in East China. Akiyosbi belt probably belongs to the youngest age category of 1.2-0.85 Ga.
Some metasedimentary rocks from the Ryoke belt have extremely high Sm-147/Nd-144 and Nd-143/Nd-144 ratios, whose main components are probably derived from mafic igneous rocks within the Ryoke belt itself and from the adjacent Tamba belt. (c) 2005 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.