@article{oai:soar-ir.repo.nii.ac.jp:00020700,
 author = {Nishio, Mayuko and Yoshida, Kohki},
 journal = {CRETACEOUS RESEARCH},
 month = {Mar},
 note = {Tectonic histories of sedimentary basins in the Cretaceous Japan arc have been assessed to understand the response of the Asian continental margin to the oblique subduction of the Paleo-Pacific (i.e. Kula or Izanagi) Plate beneath the Asian continent during the Early Cretaceous and that which subducted orthogonally in the Late Cretaceous. In the Lower Cretaceous Kuji Group (Santonian–Campanian) of the Kitakami Massif in northern Japan, sandstone petrography and chemistry of detrital heavy mineral grains were performed on sandstones to assess the tectonic environment on the basis of provenance analysis.<br/>Sandstone petrography results suggest that the material of the Kuji Group was derived mainly from areas of a Cretaceous volcanic belt (Rebun-Kabato Belt) and from a Jurassic accretionary complex (North Kitakami Terrane), which was intruded by Cretaceous granite, adjacent to the depositional basin. The chemical composition of detrital garnets suggests a North Kitakami Terrane origin, and detrital tourmalines are considered to have been derived mainly from meta-sedimentary rocks. The composition of detrital chromian spinels are compositionally diverse and mainly derived from tholeiitic and intra-plate basalts showing high TiO2 (>about 1.0 wt%) and island arc basalts with moderately low TiO2 (1.0 > TiO2 > 0.5 wt%) and high Cr#. Latter chromian spinels can be considered as a record of island arc activity including high Mg-andesite in Early Cretaceous time. Because adequate source rocks of the spinels are elusive near the basin compared with those of detrital garnets and tourmalines, these rocks are believed to have been disturbed by Cenozoic tectonics and eroded and covered by newly formed volcanic and sedimentary rocks.<br/>Comparison of chemical composition of the chromian spinels between Lower and Upper Cretaceous deposits in northern Japan indicates that chromian spinels with very low TiO2 (<0.5 wt%) prevail in the Lower Cretaceous (Aptian–Albian). In contrast, chromian spinels showing moderately low TiO2 predominated in the Upper Cretaceous (Santonian–Campanian). This clear difference suggests the change of oceanic plate motion around Japan arc promoted the change of source rock assemblage and the arc volcanic activity in mid-Cretaceous time. Thus the characteristics of detrital heavy mineral composition of the Kuji Group give the key to clarify the interaction between the swaying of young and hot plate and development of the Cretaceous island arc in eastern Asian margin., Article, CRETACEOUS RESEARCH.48:39-53(2014)},
 pages = {39--53},
 title = {Tectonic constraints to Cretaceous magmatic arc deduced from detrital heavy minerals in northeastern Japan – evidence from detrital garnets, tourmalines and chromian spinels},
 volume = {48},
 year = {2014}
}