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Journal Articles

Position-by-position cooling paths within the Toki granite, central Japan; Constraints and the relation with fracture population in a pluton

Yuguchi, Takashi*; Sueoka, Shigeru; Iwano, Hideki*; Izumino, Yuya*; Ishibashi, Masayuki; Danhara, Toru*; Sasao, Eiji; Hirata, Takafumi*; Nishiyama, Tadao*

Journal of Asian Earth Sciences, 169, p.47 - 66, 2019/01

 Times Cited Count:1 Percentile:16.4(Geosciences, Multidisciplinary)

This study presents position-by-position t-T paths within a granitic pluton based on thermochronological data, and describes their constraints and their relationship with fracture frequency, as an example from the Toki granite, central Japan. The cooling paths have position-specific characteristics; a single t-T path does not represent the cooling behavior of the entire pluton. Such position-specific t-T paths enable us to evaluate three-dimensional thermal evolution within the granitic pluton, and thus can clarify the detailed formation history of the entire pluton after the incipient intrusion of the granitic magma into the shallow crust. This study reveals the relationship between position-specific t-T paths and fracture frequency, and thus provides a criterion for evaluating the fracture population in terms of thermal stress.

Journal Articles

Formation age and cooling history of Kojaku granite

Sueoka, Shigeru; Shimada, Koji; Ishimaru, Tsuneari; Danhara, Toru*; Iwano, Hideki*; Yagi, Koshi*

Chigaku Zasshi, 127(6), p.795 - 803, 2018/12

no abstracts in English

Journal Articles

U-Pb dating of calcite using LA-ICP-MS; Instrumental setup for non-matrix-matched age dating and determination of analytical areas using elemental imaging

Yokoyama, Tatsunori; Kimura, Junichi*; Mitsuguchi, Takehiro; Danhara, Toru*; Hirata, Takafumi*; Sakata, Shuhei*; Iwano, Hideki*; Maruyama, Seiji*; Chang, Q.*; Miyazaki, Takashi*; et al.

Geochemical Journal, 52(6), p.531 - 540, 2018/12

 Times Cited Count:1 Percentile:52.17(Geochemistry & Geophysics)

Journal Articles

Zircon U-Pb and reassessed zircon fission track ages of Miocene Mizunami and Iwamura Groups in the southeastern part of Gifu Prefecture, central Japan

Sasao, Eiji; Danhara, Toru*; Iwano, Hideki*; Hirata, Takafumi*

Chishitsugaku Zasshi, 124(2), p.141 - 150, 2018/02

Here U-Pb and reassessed fission track (FT) ages are presented for samples from the Miocene Mizunami and Iwamura groups in the southeastern Gifu Prefecture, central Japan. The U-Pb ages of three tuff samples coincide with the reassessed FT ages within the error range. These new U-Pb and reassessed FT ages are consistent with those reported in previous microfossil and paleomagnetic studies, which indicate the following depositional history: The Hongo and Akeyo formations of the Mizunami Group were deposited at ~19-18 Ma and ca. 18 Ma, respectively, and the lower part of the Toyama Formation of the Iwamura Group was deposited ca. 18 Ma.

Journal Articles

Spatial distribution of the apatite fission-track ages in the Toki granite, central Japan; Exhumation rate of a Cretaceous pluton emplaced in the East Asian continental margin

Yuguchi, Takashi*; Sueoka, Shigeru; Iwano, Hideki*; Danhara, Toru*; Ishibashi, Masayuki; Sasao, Eiji; Nishiyama, Tadao*

Island Arc, 26(6), p.e12219_1 - e12219_15, 2017/11

 Times Cited Count:3 Percentile:49.96(Geosciences, Multidisciplinary)

The spatial distribution of AFT age in the granitic body is a favorable key to reveal a cooling behavior of the whole pluton. The cooling behavior is attributable to the regional exhumation of the Toki granite related to the regional denudation of the Tono district. Combination of the AERs and AFT inverse model applying to the granite is a powerful procedure for evaluating the cooling and exhumation history of the granitic pluton and thus denudation history of the tectonic region that surrounded the rock body.

Journal Articles

Fission track dating of faulting events accommodating plastic deformation of biotites

Sueoka, Shigeru; Shimada, Koji; Ishimaru, Tsuneari; Niwa, Masakazu; Yasue, Kenichi; Umeda, Koji*; Danhara, Toru*; Iwano, Hideki*

Journal of Geophysical Research; Solid Earth, 122(3), p.1848 - 1859, 2017/03

no abstracts in English

Journal Articles

Dating of crush zones associated with plastic deformation of biotite; Constraints by fission-track thermochronometry

Sueoka, Shigeru; Shimada, Koji; Ishimaru, Tsuneari; Niwa, Masakazu; Yasue, Kenichi; Umeda, Koji*; Danhara, Toru*; Iwano, Hideki*

Fisshion, Torakku Nyusureta, (29), p.5 - 7, 2016/12

no abstracts in English

Journal Articles

Cooling and denudation history of the Tsuruga body of Kojaku granite, southwest Japan, constrained from multi-system thermochronology

Sueoka, Shigeru; Umeda, Koji; Yasue, Kenichi; Niwa, Masakazu; Shimada, Koji; Ishimaru, Tsuneari; Danhara, Toru*; Iwano, Hideki*; Yagi, Koshi*

Chigaku Zasshi, 125(2), p.201 - 219, 2016/04

We applied multi-system thermochronology to the Tsuruga body of the Kojaku granite to constrain the cooling/denudation history of the Tsuruga area. Based on the thermochronometric results and other data, we reconstructed the cooling and denudation histories of the Tsuruga body as below: (1) the Tsuruga body intruded at c.a. 68 Ma at the depth of 4-5 km, (2) rapidly cooled down to c.a. 200$$^{circ}$$C by heat conduction within a few million years or less, and (3) slowly cooled due to peneplanation during the Cenozoic. This cooling/denudation history is consistent with the observations that cataclasite and fault gouge are dominant in the crush zones of the Tsuruga body, that similar slow cooling histories over the Cenozoic are estimated in the surrounding areas based on thermochronometric ages, and that the amount of denudation in the last few million years in the Tsuruga area is inferred at less than several hundred meters from the elevations of the uplifted peneplains.

Journal Articles

Identification of pumice derived from historic eruption in the same volcano; Case study for the Sakurajima-Bunmei tephra in the Miyazaki Plain

Ikuta, Masafumi*; Niwa, Masakazu; Danhara, Toru*; Yamashita, Toru*; Maruyama, Seiji*; Kamataki, Takanobu*; Kobayashi, Tetsuo*; Kurosawa, Hideki*; Kokubu, Yoko; Hirata, Takafumi*

Chishitsugaku Zasshi, 122(3), p.89 - 107, 2016/03

We carried out mineral composition analysis, morphological classification of volcanic glass shards and refractive index measurements of the glass shards and orthopyroxene from the eruption products from Sakurajima volcano. In this study, refractive indexes of hydrated and non-hydrated parts within each individual glass shard were measured separately. This measurements in consideration of hydration in glass shards made possible distinct discrimination of the pumice samples from the three eruption events of Bunmei, An-ei, and Taisho. Pumice layers in the core samples obtained from the southern part of the Miyazaki Plain were also identified as the Sakurajima-Bunmei tephra by the above mentioned analyses, and also by the data of radiocarbon dating for coaly materials included in the pumice layers. Occurrences of the pumice layers suggest that the Sakurajima-Bunmei tephra could have reached the southern part of Miyazaki Plain as pumice falls.

Journal Articles

Zircon growth in a granitic pluton with specific mechanisms, crystallization temperatures and U-Pb ages; Implication to the "spatiotemporal" formation process of the Toki granite, central Japan

Yuguchi, Takashi*; Iwano, Hideki*; Kato, Takenori*; Sakata, Shuhei*; Hattori, Kentaro*; Hirata, Takafumi*; Sueoka, Shigeru; Danhara, Toru*; Ishibashi, Masayuki; Sasao, Eiji; et al.

Journal of Mineralogical and Petrological Sciences, 111(1), p.9 - 34, 2016/02

 Times Cited Count:4 Percentile:58.43(Mineralogy)

Zircon growth collected from a granitic pluton shows four (1st - 4th) events with specific mechanisms, crystallization temperatures and U-Pb ages, revealing the sequential formation process from intrusion through emplacement to crystallization / solidification. The events are recognized by: (1) internal structure of zircon based on the cathodoluminescence observation, (2) crystallization temperatures by the Ti-in-zircon thermometer in the internal structure and (3) U-Pb ages in the internal structure.

Journal Articles

Stratigraphy and AMS radiocarbon dates of cored sediments (IrBH-2) from the Irosin Caldera, the Philippines

Mirabueno, M. H. T.*; Torii, Masayuki*; Laguerta, E. P.*; Delos Reyes, P. J.*; Fujiki, Toshiyuki*; Bariso, E. B.*; Okuno, Mitsuru*; Nakamura, Toshio*; Danhara, Toru*; Kokubu, Yoko; et al.

Chigaku Zasshi, 123(5), p.751 - 760, 2014/10

Core drilling at site IRBH-2 within Irosin caldera, southern Luzon, reached 50 m. Systematic logging and documentation were done to describe the sediments. AMS $$^{14}$$C dates were obtained for plant fragments from the peaty layers. Lahars and fluvial deposits were the predominant deposits in the core sequence. The upper 12 m was comprised mostly by andesitic fluvial and minor lahars. Eight fallouts were intercalated with reworked sediments from depth interval of 20 to 50 m. The refractive index measurement of analyzed samples indicated that post-caldera eruptions generated andesite, dacite and minor rhyolite. The similarity in petrographic characteristics between the rhyolite fallout and the Irosin ignimbrite indicates that small-scale eruptions involving magma from the caldera event occurred during post-caldera stage.Young radiocarbon dates obtained from the peaty layers shows that volcaniclastic deposits in the upper levels were likely derived from the eruptions of Bulusan volcano.

Journal Articles

Thermochronology and the three-dimensional cooling pattern of a granitic pluton; An Example from the Toki granite, Central Japan

Yuguchi, Takashi; Amano, Kenji; Tsuruta, Tadahiko; Danhara, Toru*; Nishiyama, Tadao*

Contributions to Mineralogy and Petrology, 162(5), p.1063 - 1077, 2011/11

 Times Cited Count:14 Percentile:41.54(Geochemistry & Geophysics)

Journal Articles

Fission track ages of the Miocene Mizunami and Iwamura Groups in southeastern Gifu Prefecture, central Japan

Sasao, Eiji; Danhara, Toru*; Iwano, Hideki*; Hayashi, Joji*

Chishitsugaku Zasshi, 117(8), p.476 - 481, 2011/08

Fission track age dating was done on 14 tuff samples from the Miocene Mizunami and Iwamura Groups, distributed in the southeastern part of Gifu Prefecture, central Japan. The depositional ages are estimated to be as follows: about 17 Ma (the Hongo Formation) and 17-16 Ma (the Akeyo Formation) for the Mizunami Group, 20-18 Ma (the Agi Formation) and 17-16 Ma (the middle part of the Toyama Formation) for the Iwamura Group. In terms of correlation of the Mizunami and Iwamura Groups and the Kani Group on the west side of the Mizunami Group, the Akeyo and Hongo Formations of the Mizunami Group correlate with the Toyama Formation of the Iwamura Group and the Hiramaki Formation of the Kani Group, respectively.

Journal Articles

Zircon fission-track ages for pyroclastics from the Mutsu-Hiuchidake volcano and the basement rocks, Northeast Japan; Re-examination of the latest volcanic history

Umeda, Koji; Danhara, Toru*

Ganseki Kobutsu Kagaku, 37(5), p.131 - 136, 2008/09

The fission-track ages of zircons for four volcaniclastics from the Mutsu-Hiuchidake volcano and it's basement, Northeast Japan, are determined as 0.81$$pm$$0.14 Ma and 0.77$$pm$$0.10 Ma (pyroclastic flow deposits), 2.6$$pm$$0.2 Ma and 3.0$$pm$$0.3 Ma (basement rocks). The activity period of the volcano is estimated to be from 1.2 to 0.5 Ma, based on FT ages, K-Ar ages, TL ages and stratigraphic relationships.

Journal Articles

Thermochronology of non-volcanic hydrothermal activity in the Kii Peninsula, Southwest Japan; Evidence from fission track dating and helium isotopes in paleo-hydrothermal fluids

Umeda, Koji; Hanamuro, Takahiro; Yamada, Kunimi; Negishi, Yoshimitsu*; Iwano, Hideki*; Danhara, Toru*

Radiation Measurements, 42(10), p.1647 - 1654, 2007/11

 Times Cited Count:2 Percentile:78.08(Nuclear Science & Technology)

Fission track dating of zircon and apatite samples from the altered host rocks around three hot springs were carried out in order to elucidate the thermochronology of the hydrothermal system in this non-volcanic region. The apatite FT ages from the altered host rocks around the hot springs ranged from 2.7 to 5.6 Ma, which are significantly younger than the 12 Ma age of the non-altered host rocks far from the hot springs. In the southern Kii Peninsula, therefore, it is obvious that the non-volcanic hydrothermal activity already has been ongoing since around 6 Ma.

Journal Articles

Fission track ages of the Miocene Mizunami, Iwamura and Kani Groups in the eastern part of the Setouchi Province, central Japan

Sasao, Eiji; Danhara, Toru*; Iwano, Hideki*

Fisshion, Torakku Nyusureta, (20), p.42 - 43, 2007/00

no abstracts in English

Journal Articles

Fission track ages of tuffaceous sandstone from the Toki lignite-bearing formation of the Mizunami group in the Tono district, Gifu prefecture, central Japan

Sasao, Eiji; Iwano, Hideki*; Danhara, Toru*

Chishitsugaku Zasshi, 112(7), p.459 - 468, 2006/07

Depositional age of the Toki Lignite-bearing Formation of the lowermost part of the Miocene Mizunami Group, which is distributed in the southeastern part of the Gifu Prefecture, central Japan, has been investigated by fission track (FT) dating and petrographic description. The samples used here are four tuffaceous sandstones collected from drilling cores and two granites of the Toki Granite, which is possible source of detritus of the Toki Lignite-bearing Formation. Tuffaceous sandstones are estimated to be mixture of andesitic tuff and granitic detritus. Two FT age clusters, 17-21 Ma (early Miocene) and 56-67 Ma (late Cretaceous to early Tertiary) are obtained by a statistical treatment of the distribution of zircon grain age. The younger age cluster is regarded as the age of andesitic tuff, indicating the depositional age of the Toki Lignite-bearing Formation. The older age cluster is nearly same as the zircon FT age of the Toki Granite (59-61 Ma). The depositional age of the Toki Lignite-bearing Formation is inferred to range from 18.5 to 21 Ma, taking the previous study on the depositional age of the overlying formation into consideration.

Journal Articles

Evaluation of Thermal Effect of a Large-Scale Pyroclastic Flow Deposits on Basement Rocks by Fission-Track Method

Kakuta, Chifumi; Kakuta, Chifumi; Matsuzaki, Tatsuji*; Ishimaru, Tsuneari; Kamata, Hiroki*; Danhara, Toru*; Iwano, Hideki*

Oyo Chishitsu, 45(4), p.238 - 248, 2004/00

None

Journal Articles

None

; Dennis Ede*; Danhara, Toru*

Gekkan Chikyu, 23(9), p.610 - 613, 2001/00

None

JAEA Reports

None

Iwano, Hideki*; *; Danhara, Toru*

JNC-TJ7400 99-011, 130 Pages, 1999/03

JNC-TJ7400-99-011.pdf:3.92MB

no abstracts in English

52 (Records 1-20 displayed on this page)