Fission-track dating of the Shionomisaki Igneous Complex, Kii Peninsula, Japan.

博幸, 星; 英樹, 岩野; 徹, 檀原; 武義, 吉田

doi:10.5575/geosoc.109.139

Cited by 20 publications

(11 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At Cape Shiono, gabbroic rock occurs together with S‐type granite [ Miyake , ]. This basic rock has been dated to approximately 13–15 Ma [ Hoshi et al , ; Shinjoe et al , ] and is similar in character to MORB [ Miyake , ]. The magmatism observed here is taken to be evidence of active ridge subduction of the PSP's Shikoku Basin [e.g., Kimura et al , ; Yamaji and Yoshida , ].…”

Section: Geology and Geophysics Of The Shimanto Belt On The Kii Peninmentioning

confidence: 91%

Middle Miocene swift migration of the TTT triple junction and rapid crustal growth in southwest Japan: A review

et al. 2014

View full text Add to dashboard Cite

We review recent progress in geological and geophysical investigation in SW Japan, Nankai Trough, and Philippine Sea Plate (PSP), and propose a hypothesis for the Miocene tectonics in SW Japan driven by middle Miocene swift migration of the TTT (trench-trench-trench) triple junction. The new hypothesis is based on the new interpretations as follows. Near-trench magmatism in the outer zone of SW Japan is ascribed to a collision of proto-Izu arc in addition to the previous model of an oceanic ridge of the Shikoku Basin and hot PSP subduction. The indentation structures at Capes Ashizuri, Muroto in Shikoku, and Shiono on the Kii Peninsula were previously explained by "kink folding" due to recent E-W compression. We alternatively suppose the collision of the active arc or topographic peaks such as seamounts inferred from geological and experimental observations. The main crustal component in SW Japan is suggested to be of igneous plutonic rocks rather than the previous interpretation of Cretaceous to Tertiary accretionary complexes. This is typically illustrated in the outer zone to the north of Capes Ashizuri, Muroto, and Shiono from geophysical observation of gravity anomalies, velocity and resistivity, together with geological estimations of caldera age and the size of its root pluton. Episodic crustal growth due to intrusion of igneous rock and subduction of the PSP may have stopped after approximately 12 Ma and restarted at approximately 6 Ma. Our emphasis for this gap is a cessation and resurgence of subduction rather than the previous interpretation, i.e., decreasing of subduction rate.

show abstract

Section: Geology and Geophysics Of The Shimanto Belt On The Kii Peninmentioning

confidence: 91%

Middle Miocene swift migration of the TTT triple junction and rapid crustal growth in southwest Japan: A review

et al. 2014

View full text Add to dashboard Cite

show abstract

“…In terms of our tectonic sequence, the related event is assigned to Event 3 that shows NNW–SSE compression and ENE–WSW extension, which is recognized at several sites. The ages of the dykes including the Hashigui‐iwa rock were dated to be 14.7 ± 0.5 Ma by the K–Ar method (Agency for Natural Resources and Energy 1989) and 13 Ma by the FT method (Hoshi et al . 2003).…”

Section: Discussionmentioning

confidence: 99%

“…1993; Sumii et al . 1998; Hoshi et al . 2003; see also Miura & Wada 2007), the Shionomisaki igneous complex seems to be nearly contemporaneous with the Kumano acidic rocks.…”

Section: Geological Settingmentioning

confidence: 99%

“…The Shionomisaki igneous rocks are composed largely of two types of rocks: (i) extrusive rhyolitic pyroclastic rocks and basalt lava (16–15 Ma); and (ii) intrusive granophyre, dolerite, and gabbro (Miyake 1981). The ages of these intrusive rocks range 15–13 Ma (Hoshi et al . 2003).…”

Section: Geological Settingmentioning

confidence: 99%

“…The dyke swarm consists of quartz porphyry, feldspar porphyry and orbicular granitoids. Ages of two dykes were obtained: one is at 14.7 ± 0.5 Ma by the K–Ar method (Agency for Natural Resources and Energy 1989) and the other ( Hashigui‐iwa ) is at about 13 Ma by the FT method (Hoshi et al . 2003).…”

Section: Geological Settingmentioning

confidence: 99%

See 2 more Smart Citations

Fault tectonic analysis of Kii peninsula, Southwest Japan: Preliminary approach to Neogene paleostress sequence near the Nankai subduction zone

2011

View full text Add to dashboard Cite

The southern part of the Outer Zone of Southwest Japan including the Kii peninsula belongs to the tectonic 'shadow zone', where fewer conspicuous active faults and less Quaternary sediments develop than in the Nankai subduction zone and Inner Zone of Southwest Japan. In order to study the paleostress sequence of the Kii peninsula, we analyzed fault-slip data and tension gashes at pilot sites of Early-Middle Miocene forearc sediments and Late Cretaceous accretionary complex. According to the results, six faulting events are reconstructed in sequence: (i) east-west extension (normal faulting); (ii) eastwest compression and north-south extension (strike-slip faulting); (iii) NNW-SSE compression and ENE-WSW extension (strike-slip faulting); (iv) northeast-southwest compression and northwest-southeast extension (strike-slip faulting); (v) WNW-ESE compression (strike-slip or reverse faulting); and (vi) NNE-SSW extension. The northsouth to NNW-SSE trending dyke swarm of Middle Miocene age in the Kii peninsula is thought to be related to Event 3, implying that Event 3 was active at least during the Middle Miocene. Because Event 6 is recognized solely at a site, the overall latest faulting event seems to be Event 5. Assuming that the compression results from the motion of the crust or plate, the compression direction of Event 5 is in good accordance with the presentday WNW crustal velocity vectors of the Kii peninsula. The stress trajectory map of Southeast Korea and Southwest Japan reveals that the current compression directions of the Kii peninsula correspond to the combinatory stress fields of the Himalayan and Philippine Sea tectonic domains.

show abstract