Along-arc lateral variation of Rb−Sr and K−Ar ages of Cretaceous granitic rocks in Southwest Japan

Nakajima, Takahito; Shirahase, Teruo; Shibata, Ken

doi:10.1007/bf01575616

Cited by 101 publications

(82 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other 3 results of ridge-approach model by Iwamori (2000), which incorporates mantle convection at depths >30 km and uses v = 6.3 cm/year, are shown by dashed bold lines labeled by the corresponding ages of the slab at trench, 2.5, 1.0 and 0 Ma. Katayama et al 2001 540 Ma Okamoto et al 2004-Miyamoto et al, 2007 ; Engebretson 89 Ma Okudaira and Yoshitake, 2004Nakajima et al, 1990;, 1991;Otsuki, 1992;, 1993;Sakaguchi, 1996;Maruyama et al, 1997;Iwamori, 2000;Aoya et al, 2003Wallis et al, 2009Nakajima et al, 2004aNakajima et al, 1990;, 199385-80 Ma Wallis et al, 2009Taira et al, 2016 89 Ma 86 Ma…”

Section: Fettes and Desmons 2007mentioning

confidence: 99%

Recognition of the ‘early’ Sambagawa metamorphism and a schematic cross-section of the Late-Cretaceous Sambagawa subduction zone

Aoya¹,

Endo²

2017

Jour. Geol. Soc. Japan

View full text Add to dashboard Cite

Recent petrological studies on the Sambagawa metamorphic belt in Shikoku have recognized that the coarse-grained eclogite-bearing lithologies (so-called tectonic blocks in earlier studies) in the Besshi area exclusively preserve evidence for the early Sambagawa metamorphism, which can be related to onset of the Sambagawa subduction system during Early Cretaceous (c. Ma). Geological mapping and associated multidisciplinary studies on the regional (spatially widespread) Sambagawa metamorphism (both the eclogite-facies and main metamorphisms) have revealed the tectonic framework of the Late-Cretaceous Sambagawa subduction zone as follows: (i) a spreading ridge was approaching close to the trench; (ii) the subducting slab was coupled with the convective mantle at depth of > km; (iii) thickness of the hanging-wall continental crust waskm; and (iv) the forearc mantle wedge ( -km depth) was largely serpentinized. These features allow us to draw a semi-quantitative cross-section of the Sambagawa subduction zone at around -Ma, implying that boundary conditions for thermo-mechanical modeling aiming to simulate exhumation of high-P/T metamorphic rocks are now well constrained. It has also become clear that ultramafic blocks dispersed in the higher-grade part of the Sambagawa belt were derived from the mantle wedge, i.e. the corresponding part of the belt has been re-evaluated as a fossil subduction boundary of a relatively warm subduction zone. Field-based petrological studies in the Sambagawa belt can, therefore, have potential to provide invaluable information on material behaviors at the slab-mantle wedge interface including domains of episodic tremor and slip (ETS) in presentday warm subduction zones.

show abstract

Section: Fettes and Desmons 2007mentioning

confidence: 99%

Recognition of the ‘early’ Sambagawa metamorphism and a schematic cross-section of the Late-Cretaceous Sambagawa subduction zone

Aoya¹,

Endo²

2017

Jour. Geol. Soc. Japan

View full text Add to dashboard Cite

show abstract

“…Granitoids in the San -yo Belt are referred as the Hiroshima Granite or the Hiroshima Batholith. Previous K -Ar and Rb -Sr dating for granitoids from this area yielded the Late Cretaceous ages of ~ 89 -78 Ma (e.g., Shibata and Ishihara, 1974;Higashimoto et al, 1985;Nakajima et al, 1990). The Ryoke Belt is underlain by high T/P metamorphic rocks and syn -and post -tectonic granitoids.…”

Section: Geological Outline Of Sample Localitiesmentioning

confidence: 91%

Behavior of rare elements in Late Cretaceous pegmatites from the Setouchi Province, Inner Zone of Southwest Japan

Sato

Minakawa

Kato

et al. 2013

Journal of Mineralogical and Petrological Sciences

View full text Add to dashboard Cite

This paper reports the paragenesis and reaction textures of rare earth minerals such as monazite, zircon, allanite, thorite, xenotime, and apatite in pegmatites within the Setouchi Province, Inner Zone of Southwest Japan. One of the zircon grains described shows parallel growth with thorite, suggesting their limited solid solution. Xenotime grains are sometimes disseminated by thorite and overgrown by zircon. Monazite in most pegmatites is corroded and replaced with an aggregate of allanite, apatite, thorite, and occasional xenotime and zircon. Coremantle domains in zircon grains in one of the pegmatites give high Th/U ratios (0.8 -0.4) with lower U and Th contents, and rim domains give low Th/U ratios (0.5 -0.2 or less) with higher U and Th contents. The decrease of the Th/U ratio toward the rim results from the change of co -precipitating phase from monazite to thorite. The indistinguishable monazite age (81.7 ± 6.4 Ma) and zircon age for the rim domains (82.9 ± 2.1 Ma) suggest that the paragenetic change occurred during a single evolution of pegmatite. The composition of the metasomatic fluid changed from Ca -poor to Ca -rich, causing monazite corrosion and the consequent precipitation of thorite and allanite. This, in turn, regulated the Th and U contents and the Th/U ratio in associated zircon, as well as the fluid composition.

show abstract

“…Suzuki and Adachi, 1998 Nakajima et al, 1990;Kinoshita, 1999, Czamanske et al 1981 Ishihara, 1977 Sonehara and Harayama 2007208 20124 -192819321982 Tables 1 and 2 Table 1 0.5 6.0 mm Gao1: porphyritic granite type 1; Gao2: porphyritic granite type 2; Gp: granite porphyry; Gka(MME): mafic magmatic enclave in fine-grained biotite granite. Gp-4 850.6°C Table 5 50°C Christiansen 2005 Sonehara and Harayama 2007 MELTS Ghiorso andSack, 1995 Gp-4 Fe-Ti + QFM -1QFM…”

Section: Ma 60 Mamentioning

confidence: 99%

Late Cretaceous hot and dry felsic magmatism in the Nishina Mountains, Northern Japan Alps

Ueki¹,

Harayama

2012

Jour. Geol. Soc. Japan

View full text Add to dashboard Cite

Late Cretaceous crystal-rich rhyolites and related granites are widely distributed in the Inner Zone of southwest Japan. A great deal has been written about these crystal-rich rhyolites; however, little attention has been paid to their crystal-rich character.We focus on the remarkable crystal-rich character of these rocks with the aim of determining the magmatic conditions (i.e., temperature and initial water content) under which the Late Cretaceous Kizaki Rhyolite, and the associated Aoki Granite, formed within the Nishina Mountains, in the northeast of the Northern Japan Alps. The Aoki Granite contains unaltered fayalite and pyroxenes that retain information regarding the nature of the magma from which they formed. The Kizaki Rhyolite consists of a rhyolitic welded tuff, and its essential constituent (fiamme) is characterized by a crystal-rich nature ( %-% by vol.). The Aoki Granite is remarkable for its lithological variability, but may be classified into three units: ( ) fayalite-and pyroxene-bearing porphyritic granite, ( ) chilled margin granite porphyry, and ( ) mafic magmatic enclave-bearing finegrained biotite granite. These units have similar chemical compositions, characterized by high FeO*/MgO and high contents of CaO, Na O + K O, Ba, Zr, La, Ce, and Nd.We analyzed the granite porphyry of the Aoki Granite using a geothermometer and the MELTS program, and results indicate that it was generated from hot and dry magma ( -, initial water content = . %-. % by wt.). This also suggests that similar crystalrich rhyolites, widely distributed through the Inner Zone of Southwest Japan, were generated from similarly hot and dry magmas, and that such magmatism was vigorous during the Late Cretaceous at the eastern margin of the Eurasian continent.

show abstract

Along-arc lateral variation of Rb−Sr and K−Ar ages of Cretaceous granitic rocks in Southwest Japan

Cited by 101 publications

References 41 publications

Recognition of the ‘early’ Sambagawa metamorphism and a schematic cross-section of the Late-Cretaceous Sambagawa subduction zone

Recognition of the ‘early’ Sambagawa metamorphism and a schematic cross-section of the Late-Cretaceous Sambagawa subduction zone

Behavior of rare elements in Late Cretaceous pegmatites from the Setouchi Province, Inner Zone of Southwest Japan

Late Cretaceous hot and dry felsic magmatism in the Nishina Mountains, Northern Japan Alps

Contact Info

Product

Resources

About