Late Quaternary evolution and activity of the northern part of the western marginal fault zone of Nagano Basin, central Japan

• Miyauchi Takahiro

  Earth Science Department, Chiba University

• Takeda Daisuke

  PASCO CORPORATION

Bibliographic Information

Other Title

• 長野盆地西縁断層帯北部,飯山盆地周辺の断層変位地形と第四紀後期の発達過程

Abstract

The western marginal fault zone of Nagano Basin has been a tectonically active in late Quaternary, appearing as a reverse fault by strongly crustal shortening in the northern Fossa Magna area, central Japan. The Iiyama Basin is a northern part of the tectonically subsided basin by such faulting. However, two groups of evenly running faults have migrated forward since middle Pleistocene, accumulatively deforming the fluvial terraces, and the previous basin area around the Chikuma River changed the upthrown side. Average vertical slip rate is evaluated to be> 0.2 m/ka in the eastern group of migrated faults, and around lm/ka in the western group, based on the displacement and age of fluvial terraces. This indicates that both migrated fault groups have been active in late Quaternary, possibly partitioning the fault slip by horizontal crustal shortening.

Journal

• Active Fault Research

  Active Fault Research 2004 (24), 77-84, 2004

  Japanese Society for Active Fault Studies

Keywords

• Western marginal fault zone of Nagano Basin
• Iiyama Basin
• reverse fault
• fault thrust migration
• slip partitioning

Details

• CRID: 1390001204429693824
• NII Article ID: 130003355470
• DOI: 10.11462/afr1985.2004.24_77
• ISSN: 09181024
• Text Lang: ja
• Data Source:
  • JaLC
  • CiNii Articles
• Abstract License Flag: Disallowed