Analysis of normal fault populations in the Kumano forearc basin, Nankai Trough, Japan: 2. Principal axes of stress and strain from inversion of fault orientations

2013 ◽  
Vol 14 (6) ◽  
pp. 1973-1988 ◽  
Author(s):  
Alison Sacks ◽  
Demian M. Saffer ◽  
Donald Fisher
Keyword(s):  
Nankai Trough ◽  
Normal Fault ◽  
Stress And Strain ◽  
Forearc Basin ◽  
Principal Axes

Metal-ion-induced expression of gene fragments from subseafloor micro-organisms in the Kumano forearc basin, Nankai Trough

2018 ◽  
Vol 125 (5) ◽  
pp. 1396-1407
Author(s):  
T. Wakamatsu ◽  
Y. Morono ◽  
T. Futagami ◽  
T. Terada ◽  
S. Nishikawa ◽  
...  
Keyword(s):  
Metal Ion ◽  
Nankai Trough ◽  
Forearc Basin ◽  
Induced Expression ◽  
Micro Organisms

scholarly journals Hydrocarbon seepage and its sources at mud volcanoes of the Kumano forearc basin, Nankai Trough subduction zone

2014 ◽  
Vol 15 (6) ◽  
pp. 2180-2194 ◽  
Author(s):  
Thomas Pape ◽  
Patrizia Geprägs ◽  
Sebastian Hammerschmidt ◽  
Paul Wintersteller ◽  
Jiangong Wei ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Nankai Trough ◽  
Mud Volcanoes ◽  
Forearc Basin

Structural framework and regional significance of the Northandean Cretaceous subduction cycle

2020 ◽  
Author(s):  
Andreas Kammer ◽  
Michael Avila
Keyword(s):  
Subduction Zones ◽  
Normal Fault ◽  
Large Igneous Province ◽  
Mantle Flow ◽  
Spreading Ridge ◽  
Forearc Basin ◽  
Plate Convergence ◽  
Continental Plate ◽  
Igneous Province ◽  
Cretaceous Subduction

<p>The Northandean plate margin underwent a fundamental change in its structural configuration during a Cretaceous subduction cycle, as evidenced by the formation and accretion of a province of basic igneous arc rocks that gave rise to the basement of an Northandean Western Cordillera. Further north, this igneous terrane links to the Caribbean Large Igneous Province and has been associated, with respect to its origin, to an actively spreading ridge of the Farallon plate, implying a far-travelled origin with respect to Southamerica and calling for the existence of giant strike-slip faults. We challenge this allochthonous scenario by an alternative option of a forearc origin, invoking the possibility of a forearc opening by the forcing of a toroidal mantle flow at the northern end of the Andean trench, which would have introduced mantle material from the Pacific into the Andean realm through a Central American gap. Support for such an opening mode of a forearc basin comes from extensional tectonics, that accompanied the emplacement of the basic arc units and a concomitant subduction of the extrusive basic units at the inner border of this postulated forearc basin. This intraplate subduction comprises a distinct three-partite evolution: (I) Convergence first became manifest by the reactivation of a normal fault located within the supposed forearc basin and inboard of an inherited Triassic-Jurassic suture, but still failed at a crustal level. (II) A succeeding contractional stage involved the reactivation of the inherited Triassic-Jurassic suture and the tectonic erosion of a frontal compartment of the continental margin. After an incipient underplating, slivers of this continental compartment returned within a time span of about 20 Ma. (III) A final Late Cretaceous subduction stage evolved under the conditions of an oblique SW-NE oriented plate convergence and is characterized by extensional pulses, as may be concluded from the structural setting of the giant Antioquia batholith. In the Campanian subduction definitely locked, as evidenced by the regional buckling of the forearc realm and a rebound of the upper continental plate. Both onset and shutoff of this subduction cycle may be linked to deformation phases and are dated by syntectonic, fault-guided intrusions. This scenario of a forearc origin of the basic igneous province calls for the existence of two paired subduction zones: on its outer margin the subducting Farallon slab imposed a trench-parallel mantle flow and constrained an expansion of the forarc basin by slab rollback. On its inner margin, a secondary subduction compensated a surplus expansion of the actively forming forearc basin.</p>

Gas hydrate saturation and distribution in the Kumano Forearc Basin of the Nankai Trough

2017 ◽  
Vol 48 (2) ◽  
pp. 137-150 ◽  
Author(s):  
Jihui Jia ◽  
Takeshi Tsuji ◽  
Toshifumi Matsuoka
Keyword(s):  
Gas Hydrate ◽  
Nankai Trough ◽  
Forearc Basin ◽  
Hydrate Saturation

scholarly journals STRUCTURAL AND EARTHQUAKE EVALUATIONS ALONG JAVA SUBDUCTION ZONE, INDONESIA

2020 ◽  
Vol 30 (1) ◽  
pp. 65
Author(s):  
Adi Patria ◽  
Atin Nur Aulia
Keyword(s):  
Subduction Zone ◽  
Normal Fault ◽  
Thrust Fault ◽  
Earthquake Activity ◽  
Accretionary Wedge ◽  
Forearc Basin ◽  
Plate Interface ◽  
Seafloor Morphology ◽  
Australian Plate ◽  
Seismic Reflection Profiles

Java Subduction is a zone of trench perpendicular convergence of Australian Plate and Southeast Asia in the south of Java. It is characterized by an almost E-W trending trench with an eastward increase of convergence velocity. Three major earthquakes with tsunamis have been caused by deformation along this subduction zone. Although many studies have undertaken to understand the nature of the subduction system, a clear relationship between structures and earthquake activities remains poorly explained. In this study, we used bathymetry, residual bathymetry, and published seismic reflection profiles to evaluate structural and morphological elements, then link the observations to earthquake activity along Java Subduction Zone. Based on seafloor morphology, characteristics of the accretionary wedge and forearc basin varies along the trench in response to the variation of seafloor morphology. Features such as seamounts and ridges which were observed in the oceanic basin may be subducted beneath accretionary wedge and disrupt the morphology of accretionary wedge, forearc basin, and trench. Earthquake activities are generally dominated by normal fault solutions in the trench, which is attributed to plate bending faults while thrust fault solution is observed in the forearc basin area. Thrust fault activities in accretionary wedge are decreased to the east, where there is no thrust fault solution observed in the eastern end of the subduction zone. Few strike-slip focal mechanisms are observed and mainly located within the subducting oceanic plate. Structures and subducting oceanic features may control the earthquake activity where deformation occurred at the edge of these features. The two largest thrust fault earthquakes in 1994 and 2006 are interpreted as a result of deformation along with plate interface on soft or unconsolidated sediment above the incoming plate. The largest normal fault earthquake with a magnitude 8.3 is possibly caused by a crustal scale-fault that breaks the entire oceanic crust.ABSTRAK - Evaluasi struktur dan gempa bumi di sepanjang zona subduksi Jawa, Indonesia. Subduksi Jawa adalah zona konvergensi yang tegak lurus palung antara Lempeng Australia dan Asia Tenggara di selatan Jawa. Hal ini ditandai dengan palung berarah hampir barat–timur dengan peningkatan kecepatan konvergensi ke arah timur. Tiga gempa bumi besar dengan tsunami disebabkan oleh deformasi di sepanjang zona subduksi ini. Meskipun banyak penelitian telah dilakukan untuk memahami sifat sistem subduksi, hubungan antara struktur dan kegiatan gempa bumi masih kurang jelas. Dalam studi ini, kami menggunakan batimetri, batimetri residual, dan profil refleksi seismik untuk mengevaluasi elemen struktur dan morfologi, kemudian menghubungkan pengamatan dengan aktivitas gempa bumi di sepanjang zona subduksi Jawa. Berdasarkan morfologi dasar laut, karakteristik prisma akresi dan cekungan busur muka bervariasi di sepanjang palung sebagai respon terhadap variasi morfologi dasar laut. Fitur seperti seamount dan punggungan yang diamati di cekungan samudera menunjam di bawah prisma akresi dan mengganggu morfologi prisma akresi, cekungan busur muka, dan palung. Aktivitas gempa bumi umumnya didominasi oleh patahan normal di palung, yang dikaitkan dengan patahan tekukan lempeng sedangkan patahan naik diamati di daerah cekungan busur muka. Aktivitas sesar naik di dalam prisma akresi berkurang ke arah timur, di mana tidak ada patahan naik yang teramati di ujung timur zona subduksi. Beberapa mekanisme patahan mendatar diamati dan terutama terletak di dalam lempeng samudera yang menunjam. Struktur dan fitur di kerak samudra yang menunjam dapat mengontrol aktivitas gempa bumi di mana deformasi terjadi di tepian fitur ini. Dua gempa bumi besar dengan sifat patahan naik pada tahun 1994 dan 2006 ditafsirkan sebagai hasil dari deformasi di sepanjang antarmuka lempeng pada sedimen lunak atau tidak terkonsolidasi di atas lempeng yang masuk. Gempa bumi besar dengan sifat sesar normal magnitude 8,3 mungkin disebabkan oleh patahan skala-kerak yang menghancurkan seluruh kerak samudera.

scholarly journals Mantle-derived fluids in the Nankai Trough Kumano forearc basin

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Thomas Wiersberg ◽  
Sebastian B. Hammerschmidt ◽  
Shigeshi Fuchida ◽  
Achim Kopf ◽  
Jörg Erzinger
Keyword(s):  
Nankai Trough ◽  
Forearc Basin

scholarly journals Clay Mineral Suites in Submarine Mud Volcanoes in the Kumano Forearc Basin, Nankai Trough: Constraints on the Origin of Mud Volcano Sediments

Geosciences ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 220 ◽  
Author(s):  
Akira Ijiri ◽  
Koichi Iijima ◽  
Urumu Tsunogai ◽  
Juichiro Ashi ◽  
Fumio Inagaki
Keyword(s):  
Clay Mineral ◽  
Nankai Trough ◽  
Mud Volcano ◽  
Mud Volcanoes ◽  
Forearc Basin

The integrated stress-strain analysis of calcite twins: Consistent stress and strain determined from natural data

2020 ◽  
Author(s):  
Kei Wakamori ◽  
Atsushi Yamaji
Keyword(s):  
Strain Analysis ◽  
Stress And Strain ◽  
Data Sets ◽  
Analysis Method ◽  
Stress Strain ◽  
Data Set ◽  
Principal Axes ◽  
Calcite Veins ◽  
Natural Data ◽  
Paleostress Analysis

<p>Stress and strain are different physical entities. Do the stress and strain determined from <em>e</em>-twins in a sample of polycrystalline calcite have similar principal orientations and similar shape ratios? Köpping et al. (2019) tackled this question by applying Turner’s (1953) classical method of paleostress analysis to natural data. However, despite the assumption of the method, the orientations of P- and T-axes of an <em>e</em>-twin lamella do not have a one-to-one correspondence with the principal orientations of the stress that formed the lamella. And, the method cannot determine a shape ratio. Another difficulty arises when one tackles the question: Natural calcite has usually been subjected to polyphase tectonics with different stress conditions. One has to separate stresses and to evaluate corresponding strains from a sample. Once lamellae are grouped according to the stresses, the strain achieved by the formation of a group of twin lamellae is easily evaluated by the method of Conel (1962) if the total strain represented by a group is small.</p><p>The present authors tackled the question by combining Conel’s strain analysis method with a novel method of paleostress analysis of mechanical twins, which clusters the directional data of <em>e</em>-twins by means of a statistical mixture model and determines stresses for each group of data. And, the appropriate number of stresses is determined by means of Bayesian information criterion. The method also determines the probabilities of each lamella to be formed by the stresses, which are called the memberships of the lamella. The strain achieved under a stress condition can be computed using the memberships. We applied this integrated stress-strain analysis method to Data Sets I and II from two calcite veins in a Miocene forearc basin deposit in central Japan. Since the sampling area was close to a triple-trench junction, the young formation has experienced polyphase tectonics.</p><p>As a result, we obtained the consistent stress and strains from both of the data sets. Three stresses were obtained from Data Set I, and the corresponding strains were 0.17, 0.25 and 0.13%. Two stresses were obtained from Data Set II, and the strains were 0.39 and 0.42%. The stress and strain determined from the data sets for each deformation phase were consistent with each other. That is, the principal axes had difference as small as < 20 degrees, and the shape ratios of stress and strain had also similar values. It is not straightforward to generalize this result, but both the stress and strain analyses seem to give appropriate results, providing that polyphase deformations are coped with.</p>

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