Neogene strike-slip fäulting in Sakhalin and the Japan Sea o penin g

• Main Authors: Marchour Nier, Laurent Jolivet, Konstantin F. Sergeyev, Leonid S. Oscorbin
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Noto; Sakhalin
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.629.8045; http://horizon.documentation.ird.fr/exl-doc/pleins_textes/pleins_textes_6/b_fdi_39-40/43480.pdf

We describe structural data from a 2000 km N-S dextral strike-slip zone extending f rom northem Sakhalin to the southeast comer of the Japan Sea. Satellite images, field data, and focal mechanisms of earthquakes in Sakhalin are included in the interpretation. Since Miocene time the deformation in Sakhalin has been taken up by N-S dextral strike-slip faults with a reverse component and associated en échelon folds. Narrow en échelon Neogene basins were formed along strike-slip faults and were later folded in a second stage of deformation. We propose a model of basin formation along extensional faults delimitating dominos between two major strike-slip faults, and subsequent counterclockwise rotation of the dominos in a dextral transpressional regime, basins becoming progressively oblique to the direction of maximum horizontal compression and undergoing shortening. The association of both dextral and compressional focal mechanisms of earthquakes indicates that the same transpressional regime still prevails today in Sakhalin. W e present fault set measurements undertaken in Noto Peninsula and Yatsuo Basin at the southem end of the Sakhalin-East Japan Sea strike-slip zone. Early and middle Miocene formations recorded the same transtensional regime as observed along the west coast of NE Honshu. During the early and middle Miocene the strike-slip regime was transpressional to the north in Sakhalin and Hokkaido, and transtensional to the south along the west coast of NE Honshu as far as Noto Peninsula and Yatsuo basin. Dextral motion accommodated the opening of the