"Proto-Japanese Islands" estimated by detrital minerals in Cretaceous sediments

中新生代日本海建造运动对日本岛地质带进行了重新排列。我对白垩纪浅海和非海相沉积以及基底岩石中的独居石和锆石进行了测年。我成功地确定了佐山群的精确沉积年龄。此外，来自喜门努拉群的碎屑独居岩表明，白垩纪花岗岩类在该群的物源中可能是稀有的。白垩纪增生杂岩的勘探工作是在三巴加瓦带的天龙地区进行的。尽管该地区被认为是“三巴川变质意义上的严格意义”和“岛上变质意义上的接触”，但我的研究结果清楚地表明，该地区的这两个单元都来自晚白垩世的增生杂岩。

The geologic belts in the Japanese Islands were rearranged by movement of Japan Sea formation in middle Cenozoic. I have conduced dating of monazite and zircon for Cretaceous shallow- and non- marine sediments and basement rocks. I succeeded to decide the precision sedimentary age of the Sasayama Group. In addition, detrital monazites from the Himenoura Group indicated a possibility that Cretaceous granitoids were scarce in the provenance of the group. Exploration of Cretaceous accretionary complex is conducted in the Tenryu area of the Sanbagawa Belt. Although the area was thought to be the contact of the "Sanbagawa meta-AC sensu stricto" and the "Shimanto meta-AC", the result of my study clearly indicate that both of the unit in the area originate from Late Cretaceous accretionary complexes.