Denudation of the Ryoke metamorphic belt ; timing of ductile deformation revealed by CHIME monazite dating of granitic veins

Ryoke 变质带的剥蚀；

• 批准号: 16340153
• 负责人: SUZUKI Kazuhiro
• 金额: $ 5.18万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2004
• 资助国家: 日本
• 起止时间: 2004 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-16340153/
• 关键词: Ryoke metamorphic belt; CHIME dating; denudation history; ductile deformation; burittle deformation; granitic vein; monazite; 領家変成帯; 変形花崗岩質岩脈; 非変形花崗岩質岩脈

The Ryoke metamorphic belt is a typical high T/P metamorphic belt in southwestern Japan, and consists mainly of paragneisses and associated granitoids. The paragneisses show CHIME monazite age of c. 100Ma (Suzuki & Adachi, 1989), and are injected by numerous deformed and non-deformed granitic veins of several to 30cm in thickness. The deformed veins are largely concordant with the tectonic foliation but are locally folded and boudinaged. The boudin necks are filled with the same minerals as found in the matrix. This suggests that the host gneisses were still ductile and recrystallization continued after the injection of the deformed vein. The non-deformed veins are largely discordant with straight and sharp boundaries, and seem to have formed through permeation of granitic melt into brittle fractures. This suggests that paragneisses had changed from ductile to brittle deformation conditions before the injection of the non-deformed vein. Ages of individual granitic veins with distinct d … More eformation histories can, therefore, be used to constrain the timing of the ductile-brittle transition in the Ryoke metamorphic belt. Monazites were analyzed with a JEOL JXA-733 electron microprobe equipped with 4 wavelength-dispersive spectrometers (radius of Rowland circle=140mm) through spot by spot mode. The instrument was operated at 15kV acc. voltage, 0.2μA probe current and defocused 4-6μm probe diameter. The ThMα, UMβ, PbMα and YLα lines were measured simultaneously with PET crystals and sealed Xe X-ray detectors. CaKα, SKα, PKα and NbLβ1 lines were also measured. The spectral interferences of YLγ, ThMζ and NbLβ on PbMα and ThMγ and KKα on UMβ were corrected. An U-poor young monazite was used for evaluation of correction factors of Th interferences. The detection limits at a 2σ confidence level are 0.009, 0.011 and 0.006wt.% for ThO_2, UO_2 and PbO, respectively. Relative errors are about 10% for 0.03wt.% PbO, 2% for 0.6wt.% UO_2 and 0.5% for 7.0wt.% ThO_2. All analytical data for spots containing detectable amounts of S, K and Nb were discarded for CHIME age calculation.The deformed veins show CHIME monazite ages of 93.6±6.2-89.7±5.3Ma, and the non-deformed veins show ages of 86±6-75±5Ma. The ductile deformation in the Ryoke metamorphic belt continued beyond 90Ma and ended before c.85Ma. Less

良差变质带是日本西南部典型的高T/P变质带，主要由副长岩及其伴生花岗岩类组成。副长岩显示出约100Ma的CHIME独居石年龄（Suzuki & Adachi, 1989），并由许多厚度为几至30cm的变形和未变形的花岗岩脉注入。变形脉体与构造面理作用基本一致，但局部褶皱和边界。布丁颈部充满了与基质中发现的相同的矿物质。这表明在注入变形静脉后，宿主片麻岩仍具有延展性，并继续进行再结晶。未变形的脉体与直、尖的边界极不协调，似乎是花岗岩熔体渗透到脆性裂缝中形成的。这表明，在注入未变形的静脉之前，共生岩已经从韧性变形状态转变为脆性变形状态。因此，更多的形成历史可以用来约束里奥克变质带韧脆转变的时间。利用JEOL JXA-733型电子探针，配以4台罗兰圆半径为140mm的波长色散光谱仪，采用点对点模式对单氮石进行分析。仪器在15kV电压下工作。0.2μA探针电流，4 ~ 6μm探针直径散焦。用PET晶体和密封Xe x射线探测器同时测量ThMα、UMβ、PbMα和YLα谱线。同时检测CaKα、SKα、PKα和NbLβ1。对YLγ、ThMζ和NbLβ对PbMα和ThMγ、KKα对UMβ的光谱干扰进行了校正。利用贫铀单独居石幼石对Th干扰校正系数进行了评价。在2σ置信水平上的检出限分别为0.009、0.011和0.006wt。%，分别为ThO_2， UO_2和PbO。0.03wt的相对误差约为10%。% PbO， 2%为0.6wt。% UO_2和0.5%为7.0wt。% ThO_2。所有含有可检测量的S、K和Nb的斑点的分析数据被丢弃用于CHIME年龄计算。变形脉体CHIME独居石年龄为93.6±6.2 ~ 89.7±5.3Ma，未变形脉体CHIME独居石年龄为86±6 ~ 75±5Ma。里奥克变质带的韧性变形持续到90Ma以后，在c.85Ma以前结束。少

项目成果

Quantitative chemical analysis of rocks with X-ray fluorescence analyzer XRF1800.

使用X射线荧光分析仪XRF1800对岩石进行定量化学分析。

• 发表时间: 2004
• 期刊: Bulletin of the Nagoya University Museum 20
• 作者: Nakazaki;M.;Tsuboi;M.;Kanagawa;K.;Kato;T.;Suzuki;K.
• 通讯作者: K.

Role of partial melting in the evolution of the Sulu (eastern China) ultrahigh-pressure terrane

• DOI: 10.1130/g20991.1
• 发表时间: 2005-02
• 期刊: Geology
• 影响因子: 5.8
• 作者: S. Wallis;M. Tsuboi;Kazuhiro Suzuki;M. Fanning;Laili Jiang;Tsuyoshi Tanaka

電子プローブマイクロアナライザを用いたCHIME年代測定

使用电子探针显微分析仪进行 CHIME 测年

• 发表时间: 2005
• 期刊: 地質学雑誌 111
• 作者: Wallis;S.;Tsuboi;M.;Suzuki;K.;Fanning;M.;Laili;J.;Tanaka;T.;鈴木和博
• 通讯作者: 鈴木和博

Provenance implications of Th–U–Pb electron microprobe ages from detrital monazite in the Carboniferous Upper Silesia Coal Basin, Poland

• DOI: 10.1016/j.lithos.2005.08.004
• 发表时间: 2006-05
• 期刊: Lithos
• 影响因子: 3.5
• 作者: M. Kusiak;Artur Kędzior;M. Paszkowski;Kazuhiro Suzuki;I. González-Álvarez;B. Wajsprych;M. Doktor

R Biochemical signatures preserved in ancient siliceous sediments; new perspectives to Triassic radiolarian bedded chert composition

R 古代硅质沉积物中保存的生化特征；

• 发表时间: 2006
• 期刊: Geochemical Journal 40
• 作者: Takiguchi;T.;Sugitani;K.;Yamamoto;K.;Suzuki;K.
• 通讯作者: K.