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CHIME (chemical Th-U-total Pb isochron method) dating, quantitative electron probe microanalysis (EPMA) of ultra-trace elements and ultra-light elements are performed using two JCXA-733 (JEOL, Tokyo) at Division for Chronological Research, Institute for Space-Earth Environmental Research (ISEE), Nagoya University. The 733-LSS type specimen stage has been installed and both instruments supports large size specimen holders. Available analyzing crystals are: LDE1, LDE2, NSTE, TAP, PET, and LiF. The software for quantitative analysis supports Bence-Albee method, PAP and PROZA96 models.

CHIME (chemical Th-U-total Pb isochron method) dating, quantitative electron probe microanalysis (EPMA) of ultra-trace elements and ultra-light elements are performed using two JCXA-733 (JEOL, Tokyo) at Division for Chronological Research, Institute for Space-Earth Environmental Research (ISEE), Nagoya University. X-ray fluorescence spectrometer (XRF-1800, Shimazu, Kyoto) and X-ray diffractometer (MiniFlex, Rigaku, Tokyo) are also provided for the joint research program of ISEE in addition to JCXA-733. Phase analysis software, MATCH! 3 (Crystal Impact GbR) has been introduced for XRD data analysis.

CHIME (chemical Th-U-total Pb isochron method) dating and quantitative analysis of ultra-trace elements are performed with two JCXA-733 (JEOL, Tokyo) electron probe microanalyzers (EPMA) at Division for Chronological Research, Institute for Space–Earth Environmental Research (ISEE), Nagoya University. X-ray fluorescence spectrometer (XRF-1800, Shimadzu, Kyoto) and X-ray diffractometer (MiniFlex, Rigaku, Tokyo) are also provided for the joint research program of ISEE in addition to EPMA. The control computers of XRF and XRD have been replaced by the 64-bit version of Windows 10 based computers., 名古屋大学宇宙地球環境研究所年代測定研究部では、2台の電子プローブマイクロアナライザー（EPMA、日本電子株式会社製JCXA-733）を用い、U-Th-Pb系のサブグレン年代測定や極微量元素定量分析を実施している。また、今年度から蛍光エックス線装置（株式会社島津製作所製XRF-1800）およびエックス線回折計（株式会社リガク製MiniFlex）も共同利用・共同研究対処機器としている。XRFとXRDの制御用PCを64ビット版Windows 10を搭載したものに置き換えた。

Electron probe microanalysis (EPMA) is performed using two JCXA-733 (JEOL, Tokyo) for CHIME (chemical Th-U-total Pb isochron method) dating, quantitative EPMA of ultra-trace elements and other geological applications at the Division for Chronological Research, Institute for Space–Earth Environmental Research (ISEE), Nagoya University. X-ray fluorescence spectrometer (XRF-1800, Shimadzu, Kyoto) and X-ray diffractometer (MiniFlex, Rigaku, Tokyo) are also provided for the joint research programs by ISEE in addition to JCXA-733., 名古屋大学宇宙地球環境研究所年代測定研究部では，2台の電子プローブマイクロアナライザー（EPMA，日本電子株式会社製JCXA-733）を用い，U-Th-Pb系のサブグレン年代測定や極微量元素定量分析を実施している．また，今年度から蛍光エックス線装置（株式会社島津製作所製XRF-1800）およびエックス線回折計（株式会社リガク製MiniFlex）を共同利用・共同研究に供することにした．EPMAのハードディスクを昨年度にFPGAを用いたエミュレーターに置き換えていたが，起動に7分程度かかっていた．今年度はエミュレーターを更新し，ディスクの起動時間を7秒に短縮した．また，フロッピーディスクについてもArduinoを用いたエミュレーターに置き換え，すべての記録メディアを半導体メモリーにすることができた．

A Rb-Sr whole-rock isochron age is redetermined at the Graduate School of Environmental Studies, Nagoya University, on eight samples of the Ono type of the Hikami Granite selected from Shibata (1974). The age using the original data is 371±87 Ma, whereas the redetermined age is 368±49 Ma, and both are in agreement with each other. These ages are also in agreement with a K-Ar age of 365±34 Ma on hornblende and a CHIME age of 365±34 Ma on mantle part of monazite. Based on these age data, most part of the Ono type of the Hikami Granite is assumed to have been emplaced in late Devonian., 氷上花崗岩についてShibata(1974)が使用した大野型の8試料を選別し，名古屋大学大学院環境学研究科にてRb-Sr全岩アイソクロン年代を再測定した．元のデータによる年代は371±87Ma，再測定による年代は368±49Maであり，両者は測定誤差の範囲で良い一致を示した．これらの年代は361±9MaというK-Ar角閃石年代および365±34MaというモナザイトのマントルのCHIME年代とも一致する．氷上花崗岩大野型の多くはデボン紀末の貫入岩とみなされる．

2台の電子プローブマイクロアナライザー（EPMA,日本電子株式会社JCXA-733）を用い，名古屋大学宇宙地球環境研究所ではCHIME年代測定や極微量元素EPMA定量分析を実施している．これまで旧式のディスクドライブを使用していたが，2017年度にFPGAを用いたエミュレーターで置き換え，メディアをmicroSDカードにした．これにより，小型化，省電力化を実現した．

Electron probe microanalysis (EPMA) is being performed with two electron microprobes (JCXA–733, JEOL, Tokyo) for various applications, including the CHIME dating and quantification of ultra-trace elements at the Division for Chronological Research, Institute for Space-Earth Environmental Research, Nagoya University. One of the electron microprobes is mainly used for the CHIME dating of rock-forming minerals. The other is used for various applications., 名古屋大学宇宙地球環境研究所年代測定研究部では、2台の電子プローブマイクロアナライザー(EPMA）を用いてCHIME年代測定やさまざまな分析を行っている。2016年度はEPMAなどの装置を古川記念館から研究所共同館IIに移設した。これまで2台のEPMAは異なるソフトウェアで制御していたが、装置の改造を行い共通のハードウェア・ソフトウェアで分析することができるようにした．

The geologic relation between the Hikami Granite and the fossiliferous Siluro-Devonian strata in the South Kitakami terrane has long been an open problem. Detailed CHIME dating and elemental mapping of monazite from the southern part (Hinokamiyama type) of the granite disclose ubiquitous development of Late Devonian (365±34 Ma) mantles on Silurian cores. Monazite-free granite samples (Ono type) from the northern part give a 373±35 Ma Rb-Sr whole-rock isochron age with R1=0.70669±0.00037, suggesting to be a possible heat source for the Late Devonian overprint on the Hinokamiyama type. The CHIME monazite dating also revealed (1) the granite at Kusayami-zawa, believed as the part of the Hikami Granite and interpreted to be covered unconformably by the Silurian arkose, is of Cretaceous (123±6 Ma), (2) the Silurian arkose contains Ordovician monazite without Post-Silurian age signature, (3) an arkose bed intercalated in the Devonian Ono Formation contains unequivocal Cretaceous (113±12 Ma) monazite grains, and (4) a porphyroblastic facies, being ascribed sometimes as mylonite, within the Hikami Granite contains Silurian-Late Devonian and Silurian-Late Devonian-Permian zoned monazite grains together with chronologically uniform Silurian and Cretaceous monazite grains. The porphyroblastic facies is likely to be a granitic arkose. These lines of geochronological evidence suggest that the Hikami Granite and the fossiliferous Silurian and Devonian strata are exotic blocks enclosed within a Cretaceous mélange., 南部北上帯の氷上花崗岩とシルル-デボン系の関係を明らかにするためにCHIMEモナザイト年代測定とRb-Sr全岩アイソクロン年代測定を行った．これにより，氷上花崗岩と称されてきた岩体は4.4億年花花崗岩とこれに熱変成を与えた3.6億年花崗岩(大野型の一部)，シルル-デボン系境界部付近の1.2億年花崗岩および1.2-1.1億年のアルコースの集合体であることが判明した．くさやみ沢でシルル系アルコースに直接するのは白亜紀の花崗岩であるので，その不整合関係を根拠にした従来の氷上花崗岩＝先シルル紀基盤岩説は成立しない．デボン紀大野層下部のアルコースは白亜紀(1.1-1.2億年)の砕屑モナザイトを含む．これらの新知見は氷上花崗岩やシルル紀・デボン紀の化石を含む堆積岩が白亜紀メランジェ中の異地性岩塊である可能性を示唆する．, 名古屋大学宇宙地球環境研究所年代測定研究部シンポジウム報告

Electron probe microanalysis (EPMA) is performed using two electron micro probes (JCXA- 733, JEOL, Tokyo) CHIME dating, quantitative EPMA of ultra-trace element and other applications at the Division for Chronological Research, Institute for Space-Earth Environmental Research, Nagoya University. The one is mainly used for CHIME dating of rock-forming minerals. The other is used for a variety of applications, such as quantitative EPMA of ultra-trace elements and CHIME dating., 名古屋大学宇宙地球環境研究所年代測定研究部には、2台の電子プローブマイクロアナライザー(EPMA）を用いて、CHIME年代測定及びさまざまな分析を実施し、教育・研究を行っている。2015年度は、極微量元素の定量分析の確度向上のため、高計数率エックス線の高確度測定法の開発やさまざまな地質帯の CHIME年代測定などを行った。また、EPMAの保守性維持や省電力化に向けた試みを行っている。, 名古屋大学宇宙地球環境研究所年代測定研究部シンポジウム報告

Electron probe microanalysis (EPMA), including the CHIME dating, is performed using two electron probe microanalyzer (JCXA-733, JEOL, Tokyo), at the Center for Chronological Research, Nagoya University. The one equips four wavelength dispersive spectrometers (WDS) and optimized to the CHIME dating of rock-forming minerals. The other equips five WDSs with a variety of analyzing crystals, including customized crystals for many kind of analysis of ultra-light elements through heavy elements., 名古屋大学年代測定総合研究センターでは、2台の電子プローブマイクロアナライザー(EPMA)を用いて、CHIME年代測定や関連する分析についての教育・研究を実施している。2014年度は、高感度微量元素測定と高精度エックス線干渉補正の検討を実施した。その結果、約1OMa程度のモナザイトのCHIME年代測定が可能であることが示された。また、EPMAの保守体制を整備し、当面は現有装置を維持可能な状態にした。, 名古屋大学年代測定総合研究センターシンポジウム報告

This paper outlines an optimized condition of the CHIME zircon and xenotime dating on the JEOL JXA-8530F FE-EPMA that is equipped with three R=100 mm and two R=140 mm wavelength-dispersive spectrometers. The R=100 mm spectrometer coupled with a large-sized PET crystal has the potential advantage of the count rate in the analysis of trace Pb. The disadvantage of the poor discrimination of U-Mz2 from Th-Mb was reduced by the correction. Effects of U-Mz1, Zr-Lg2.3, Pb-M4-02, Pb-AM5 and Pb-M5-03A on the background measurement were eliminated through selection of narrow interference-free windows. Reliability of the improved procedure was tested with zircon and xenotime in a sample of Tsubonosawa gneiss from Rikuzen-Takada, Iwate Prefecture. Zircon ages of 560-540 Ma and zoned xenotime ages of 460-440 Ma, 370-340 Ma and 230 Ma are compatible with isotopic ages and conventional CHIME ages. The improved CHIME dating on JXA-8530F FE-EPMA has shortened the measurement time to 1/3 of the conventional methods., 日本電子製のFE-EPMA(JXA-8530F)を使って、CHIME年代測定の測定条件の最適化を行った。CHIME年代測定には、必須の測定元素であるTh、U、Pbの特性X線は、互いに干渉し合うため、干渉補正を行う必要がある。また、各元素のバックグラウンド測定位置の設定も測定精度に大きく影響を与える。本研究では、測定に使用する分析線(特性X線)の選択や、干渉する特性X線の強度を測定し干渉補正係数を求めて干渉補正を行った。バックグラウンドの測定位置は、スペクトルをとり、他の元素の特性X線の影響のない位置で設定した。今回作成した測定条件の測定時間は1試料あたり約15分である。この測定条件を用いて南部北上帯の壷ノ沢片麻岩のジルコンとゼノタイムを測定し、年代値を求めた。本試料が、後背地の火成作用を受けたのが、約5～20億年前、変成作用は約4.4億年前、さらに熱変成を受けたのが3.5億年前と2.5億年前と報告されており、今回の測定値も同程度の年代が得られた。従って、測定条件の妥当性が確認されたと判断できる。, 名古屋大学年代測定総合研究センターシンポジウム報告

CHIME dating and related electron probe microanalysis (EPMA) are performed using two electron probe microanalyzers (JCXA-733, IEOL, Tokyo) at the Center for Chronological Research, Nagoya University. The one equips four wavelength dispersive spectrometers (WDS) and mainly used for the CHIME dating of U and Th-bearing rock-forming minerals. The other equips five WDSs with a variety of analyzing crystals, and used for many kind of analysis including general quantitative EPMA and the CHIME dating. Physical parameters in quantitative EPMA were validated and new dataset of mass attenuation coefficients was developed to improve accuracy of quantitative EPMA., 名古屋大学年代測定総合研究センター新年代測定法開発研究分野では、2台の電子プロープマイクロアナライザーを用いてCHIME年代測定及び関連するX線分光分析に関する教育・研究を行っている。平成25年度には、定量分析の補正計算で用いられる定数の検討を行い、新しい質量吸収係数のデーターセットを作成した。これにより、CHIME年代測定を含めたEPMA定量分析の確からしさが向上する。, 名古屋大学年代測定総合研究センターシンポジウム報告

CHIME dating and related electron microprobe analyses are performed with two electron microprobe analyzers (JCXA-733, JEOL, Tokyo) at the Center for Chronological Research, Nagoya University. The one equips four wavelength dispersive spectrometers and mainly used for CHIME dating. Another equips five wavelength dispersive spectrometers and used for many kind of analysis including CHIME dating. A problem of mass attenuation coefficients is found in the data set provided by Henke et al. (1993) and the matrix correction procedure is under reevaluation., 名古屋大学年代測定総合研究センターシンポジウム報告

The CHIME dating and related electron probe microanalysis (EPMA) are performed using two electron microprobe equipment (JCXA-733, JEOL, Tokyo) at the Center for Chronological Research, Nagoya University. The one equips four wavelength dispersive spectrometers (WDS) and another does three WDSs. These electron microprobes are customized by the authors for specific analysis including the CHIME dating of young samples. The CHIME dating of Miocene monazite and xenotime has been performed in 2011. In addition, REE analysis of kimuraite, lokkite and lanthanite aggregate has been performed using WDS customized to achieve 30% higher wavelength resolution than JEOL original configuration. High wavelength resolution WDS completely solves the X-ray interference problem in quantitative EPMA of L-REE., 名古屋大学年代測定総合研究センターシンポジウム報告

The CHIME dating is performed using two electron microprobes (JCXA-733, JEOL, Tokyo) at the Center for Chronological Research, Nagoya University. The one equips four wavelength dispersive spectrometers (WDS) and another does three WDS. Those electron microprobes were customized by the authors for improvement: stability, sensitivity, wavelength resolution etc. Two customized analyzing crystals were installed on the electron microprobe to achieve higher wavelength resolution than JEOL original system. The liquid nitrogen trap is installed to reduce surface contamination in quantitative electron probe microanalysis of ultra-light elements. Mineral grains are used for the standard materials of chemical compositions and X-ray interferences to avoid introduction of nuclear fuel material to the Center for Chronological research. Calibration of standard materials is periodically performed in Korea Institute of Geoscience and Mineral Resources (South Korea) using well characterized standard materials., 第23回名古屋大学年代測定総合研究センターシンポジウム平成22(2010)年度報告

The CHIME dating is performed using two electron microprobe (EMP) equipments (JCXA-733, JEOL, Tokyo) at the Center for Chronological Research, Nagoya University. The one equips four wavelength dispersive spectrometers (WDS) and the other does three WDS. Those EMP equipments were customized by the authors for improvement: stability, sensitivity, wavelength resolution etc. Two customized analyzing crystals were installed on the EMP to improve wavelength resolution. The liquid nitrogen trap (cold trap) was installed to reduce surface contamination. The integrated machine time was about 2.500 hours for the CHIME dating in 2009. The total number of analysis points was over 40,0OO excluding 2-dimensional mapping., 第22回名古屋大学年代測定総合研究センターシンポジウム平成21(2009)年度報告

Dating by the chemical Th-U-total Pb isochron method (CHIME) was carried out on xenotime, monazite and zircon from beryllium pegmatites intruded at about 2500 Ma in the ultrahigh-temperature metamorphic Napier Complex. No meaningful results were obtained on zircon from an associated Be-free pegmatite. All analyzed mineral grains are chronologically heterogeneous, and apparent ages range from -2460 Ma to 550 Ma with conspicuous concentration at 2200, 1700 and 700 Ma. The 2168±36 Ma age for the chronologically homogeneous, non-metamict core of a large xenotime grain dates intense post-emplacement deformation and metamorphism, possibly the granulite-facies event M-2 proposed by E.S. Grew et al. (Polar Geosci., 13, 1, 2000) to explain the breakdown of sapphirine and quartz to sillimanite, surinamite, orthopyroxene and/or garnet in the pegmatites and their host rocks. CHIME ages near ～1700 Ma and ～700 Ma could result from incomplete resetting by amphibolite-facies events (M-3, -4) between ～1100 and ～500 Ma. In general, the minerals appeared to have experienced no significant new growth during the later events, so that the effect of these events is expressed in the U-Th-Pb system in the original mineral. Because most of the ages were obtained on non-metamict portions of the analyzed grains, we doubt that metamictization can be the cause of most of the observed chronological heterogeneity. The lack of evidence for the ～2500 Ma emplacement age in the CHIME data could be due to the reliance on total concentrations of Th, U and Pb, which may be more affected by subsequent deformation and metamorphism than the isotope ratios measured in conventional U-Pb dating.

Th-U-bearmg minerals (monazite, zircon, xenotime and polycrase) in five granulite samples from Mt Riiser-Larsen (MA88022102), Beaver Island (2023B), Reference Peak (2306E and 2306J) and Mt Cronus (2275) in the western Napier Complex of East Antarctica were dated by CHIME on the basis of electron microprobe ThO_2, UO_2 and PbO analyses Rocks from these localities, including some of the studied samples, are characterized by sapphirine-quartz-, orthopyroxene-sillimanite- and osurmlite-beanng mineral assemblages, indicating ultra-high-temperature granuhte-facies metamorphism A few grains of monazite in Sample MA88022102 and of zircon in Sample 2275 are chronologically heterogeneous, but other analyzed grains of monazite and zircon in these samples and all analyzed grains in the other samples, including xenotime, are almost homogeneous The core of a Mt Cronus zircon grain gives the oldest CHIME age, 3646±136 Ma, which could be a minimum age for protolith formation The homogeneous minerals, together with the older domains of Mt Riiser-Larsen zoned monazite and some grains of Mt Cronus zircon, give well-defined isochrons yielding consistent ages of 2404 Ma to 2441 Ma (within±54 Ma) on the ThO_2-PbO or UO_2-PbO plots Data points from zircon in Sample 2306J and from polycrase in Sample 2275 yield no isochron Given the petrographic characteristics of the samples and the high Pb-retentivity of the Th-U-bearmg minerals, we interpret the 2404-2441 Ma CHIME ages to date the ultra-high-temperature granulite-facies metamorphism The 2404-2441 Ma ages lie in the 2400-2500 Ma range of ages reported from numerous localities in the Napier Complex In the absence of decisive evidence for inherited older grains and of significant retrograde features in the analyzed samples, we consider that the Napier ultra-high-temperature metamorphism occurred not -2800 Ma ago as interpreted by most investigators, but 2400-2500 Ma ago