From detailed stratigraphy including tephra, bio-and magneto-stratigraphy, we studied the process of folded structure development in Pliocene to early Pleistocene strata distributed in the Kashiwazaki plain and its vicinity, central Japan. Four folding phases are recognized; 1) from 2.8 to 2.4 Ma in the southern part and the southward of Chuo Hills, 2) from 2.0 to 1.5 Ma in Teradomari-Nishiyama Hills and its front area corresponding to continental shelf, 3) ca 1.0 Ma in the southern part of Chuo Hills, and 4) from 0.7 to 0.3 Ma in the northern part of Chuo and Hachikoku Hills. Besides them an active folding is observed in the eastern side of the Shinano River, the activity having commenced in latest Pleistocene.
Each folding phase was relatively short lived from 0.4 to 0.5 Ma. In general, the intervals among these folding activities were geologically calm without any notable progress of folding activity. The culmination of folding activity had successively migrated eastward since last 3 Ma.