Deformation styles and fluid-rock interaction of Minoo accretionary complex in the Tamba belt

Tatsuru Fukuta; Tetsuro Hirono

Presentation information

[J] Poster

S (Solid Earth Sciences ) » S-CG Complex & General

[S-CG46] New Insights of Fluid-Rock Interactions: From Surface to Deep Subduction Zone

Tue. May 28, 2024 5:15 PM - 6:45 PM Poster Hall (Exhibition Hall 6, Makuhari Messe)

convener:Atsushi Okamoto(Graduate School of Environmental Studies), Jun Muto(Department of Earth Sciences, Tohoku University), Ikuo Katayama(Department of Earth and Planetary Systems Science, Hiroshima University), Junichi Nakajima(Department of Earth and Planetary Sciences, Tokyo Institute of Technology)

5:15 PM - 6:45 PM

[SCG46-P09] Deformation styles and fluid-rock interaction of Minoo accretionary complex in the Tamba belt

*Tatsuru Fukuta¹, Tetsuro Hirono¹ (1.Osaka Metropolitan Univercity)

Keywords:Seismology, subduction zone, Deformation style, accretion, Tamba belt

For understanding earthquake mechanism, evaluation of slip behavior on fault is crucially important. Although direct sampling from seismogenic zone at deep-sea drilling projects has not been succeeded, onland accretionary complexes preserved ancient deformations related to plate-subduction earthquakes. In this study, we performed the field investigation of the mélange units in the Minoo complex, the Tamba belt, and the microscopic observation of the rocks from the outcrop. We found mixed rocks by mudstone and sandstone accompanying with block-in-matrix structure, broken sandstone and siliceous mudstone of strata and andesitic dykes in the outcrop and intense shear foliations within the rocks. The Minoo complex is classified as the Type II Suite in the Tamba belt, which might be closely related to underplating accretion along subduction boundary and metasomatism at the stage of uplifting.