Progressive deformation in an accretionary complex: An example from the Shimanto belt of eastern Kyushu, southwest Japan

Research Article| April 01, 1987 Progressive deformation in an accretionary complex: An example from the Shimanto belt of eastern Kyushu, southwest Japan J. S. Mackenzie; J. S. Mackenzie 1Department of Geology, Royal School of Mines, Imperial College of Science and Technology, Prince Consort Road, London SW7 2BP, England Search for other works by this author on: GSW Google Scholar D. T. Needham; D. T. Needham 2Department of Earth Sciences, University of London, Goldsmiths' College, Rachel McMillan Building, Creek Road, London SE8 3BU, England Search for other works by this author on: GSW Google Scholar S. M. Agar S. M. Agar 3Department of Geology, Royal School of Mines, Imperial College of Science and Technology, Prince Consort Road, London SW7 2BP, England Search for other works by this author on: GSW Google Scholar Author and Article Information J. S. Mackenzie 1Department of Geology, Royal School of Mines, Imperial College of Science and Technology, Prince Consort Road, London SW7 2BP, England D. T. Needham 2Department of Earth Sciences, University of London, Goldsmiths' College, Rachel McMillan Building, Creek Road, London SE8 3BU, England S. M. Agar 3Department of Geology, Royal School of Mines, Imperial College of Science and Technology, Prince Consort Road, London SW7 2BP, England Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1987) 15 (4): 353–356. https://doi.org/10.1130/0091-7613(1987)15<353:PDIAAC>2.0.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation J. S. Mackenzie, D. T. Needham, S. M. Agar; Progressive deformation in an accretionary complex: An example from the Shimanto belt of eastern Kyushu, southwest Japan. Geology 1987;; 15 (4): 353–356. doi: https://doi.org/10.1130/0091-7613(1987)15<353:PDIAAC>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The Shimanto accretionary complex of eastern Kyushu records a progressive deformational history that reflects the gradual underthrusting of sediments beneath the prism and their eventual accretion at depth to the base of the complex. Initial deformational style is controlled by grain size and porosity of the sediments. Stratal disruption of coarser grained, highly porous sandstones is accommodated by ductile intergranular flow, whereas finer grained, less porous sandstones and mudstones deform by localized shearing and brittle failure. As further reductions in porosity accompany lithification, both sandstones and mudstones continue to deform in a brittle manner. With progressive increases in pressure and temperature accompanying tectonic burial, shear bands and minor isoclinal folds are generated, deforming earlier formed fabrics and indicating a south-southeasterly shear direction. With increasing strain, these folds undergo rotation, and their axes approach that of the transport direction. A pronounced stretching lineation is typically associated with regions where these folds have been rotated, suggesting intense noncoaxial layer-parallel shear. These zones of higher shear strains may be related to thrust-fault propagation during accretion of material to the base of the prism. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.