Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.jseaes.2021.105070

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.2465/jmps.210830

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.lithos.2021.106362

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.jas.2021.105377

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.5575/geosoc.2020.0044

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.chemosphere.2020.127912

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.jseaes.2019.104077

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.jseaes.2019.104084

Language：Others   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/iar.12374

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1007/s00710-019-00680-0

Language：English  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2465/jmps.181115

Language：English  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.microc.2018.03.005

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.jseaes.2018.01.017

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.3390/min8050204

Language：Japanese  

DOI： 10.5575/geosoc.2017.0059

Language：Others  

Excavations at Daram and Tevsh Sites: A Report on Joint Mongolian-Japanese Excavations in Outer Mongolia

Language：Japanese  

日立変成地域のカンブリア系について，ジルコンU-Pb SHRIMP年代値を追加し，既報の年代値をまとめ，各地層を再定義し，地質図を改めた．層序については，早期から晩期のカンブリア系を日立火山深成複合岩体として一括し，その中に赤沢層，玉簾層，変成花崗岩類，変成ポーフィリィを含めた．玉簾層の一部を分離して滝沢層を新設した． 西堂平層の堆積年代は白亜紀前期である．さらに，白亜紀後期に火成岩貫入と中圧型変成作用が起った．これは阿武隈帯の竹貫変成岩類の変成履歴とも共通し，東北日本列島でこのような急激なテクトニクスが起こった時期があったと推定した． 古第三紀の中央構造線が日本列島全体を縦断していたと仮定して，日本海形成前における，カンブリア系を含む日立古生層と東北日本列島基盤の復元を試み，日立古生層や阿武隈帯は中国東北部の佳木斯・ハンカ地帯に近接することを示した．カンブリア系日立火山深成複合岩体は北中国地塊の東縁に帰属することを主張した．

DOI： 10.5575/geosoc.2016.0012

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2465/jmps.151227

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2465/jmps.151230

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2465/jmps.150907

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2465/jmps.151019b

Language：English   Publishing type：Research paper (scientific journal)  

The Sør Rondane Mountains in East Antarctica consist of the various metamorphic rocks and several plutonic rocks, which are related to formation of Gondwana supercontinent. In order to understand the detrital provenances, LA-ICP-MS zircon U-Pb dating were conducted from metamorphosed sedimentary rocks in southern Sør Rondane Mountains. Detrital cores with ~ 990-730 Ma ages were recognized from zircons in the pelitic gneisses and calc-silicate rocks from Menipa, Imingfjella, Mefjell and Arden, while the pelitic gneiss from Tvihøgda exhibited the Archean to Mesoproterozoic ages of ~ 2630-1060 Ma. The Neoproterozoic zircon ages are recognized not only from metamorphosed sedimentary rocks but also from metamorphosed igneous rocks distributed in the central and southern parts of the mountains. However, the Archean to Mesoproterozoic zircon ages are rare in these areas. The results imply the detrital zircons with the Neoproterozoic ages were probably derived from neighbouring igneous rocks (present metamorphosed igneous rocks), while those with Archean to Mesoproterozoic ages have clearly different provenances because of the lack in the Neoproterozoic components. This study suggests the possibility that southern Sør Rondane Mountains can be considered to be juvenile late Mesoproterozoic to Neoproterozoic terrane partly mixed with the Archean to Mesoproterozoic components.

DOI： 10.2465/jmps.151001

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.17014/ijog.2.3.139-156

Language：Japanese  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/jmg.12154

Language：Japanese   Publishing type：Research paper (scientific journal)  

  Early Cretaceous igneous rocks in the Kitakami Mountains consist of volcanic rocks, dike rocks, and plutonic rocks, from older to younger. Plutonic rocks are composed mainly of adakitic granites in central part of zoned plutonic bodies surrounded by adakitic to non-adakitic granites in marginal part. These adakitic plutons is divided into E and W zones based on the ages and geochemistry. Zircon U-Pb ages were determined with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for 22 samples from 13 rock bodies including the Early Cretaceous adakitic granites in the Kitakami Mountains. Zircons from the adakitic granites of E zone give older ages (127-117 Ma) compared with those of W zone (119-113 Ma). Zircon ages of the calc-alkaline to shoshonitic rocks and dike rocks range from 128-124 Ma, which are similar to the oldest rocks of the E zone (127-125 Ma). Zircon ages become younger from the northern Hashikami pluton and marginal facies of the Tanohata pluton (127-125 Ma) to southern Takase granites (118-117 Ma), in the E zone adakitic granites. Petrochemical differences between the E zone and W zone rocks indicate that the adakitic melt of E zone rocks are considered to be derived from vapor-absent melting condition, while those of W zone rocks are from higher pressure and vapor-present condition.   Taking all these data into consideration, the Early Cretaceous magmatisms in Kitakami can be explained by the differential subduction model of the Farallon-Izanagi plates or slab rollback model accompanied with asthenospheric upwelling.

DOI： 10.2465/gkk.131228

Language：English   Publishing type：Research paper (scientific journal)  

© 2015 by The University of Chicago. All rights reserved. Sensitive high-resolution ion microprobe (SHRIMP) U-Pb zircon age dating was applied to several types of cordieritebearing gneisses and orthopyroxene-bearing gneiss from the basement rocks in central Dronning Maud Land, East Antarctica, to clarify the timing of tectonothermal events during the amalgamation of East and West Gondwana. The zircon ages of ca. 522–525 and 598–599 Ma were obtained in Filchnerfjella and Hochlinfjellet, respectively, and the cathodoluminescence images of analyzed zircons suggest that these were formed during high-temperature metamorphism. These two sets of ages are interpreted to represent periods that immediately followed the peak metamorphism. The dating results reveal an age gap of 80 Myr between the two areas, indicating different collisional events. In the cordierite-bearing samples in Filchnerfjella, zircon cores with oscillatory zoning have concordia ages that range from 1800 to 650Ma. These are considered to represent the ages of detrital zircons derived over a long time from different source materials. In Hochlinfjellet, the inherited detrital zircons with oscillatory zoning have concordia ages of ca. 930, 780, and 730Ma, indicating sedimentary protoliths derived from differently aged igneous source rocks, possibly formed in a subduction zone as an accretionary prism before the collision. According to previous age results, previously documented shear zones are now interpreted as representing a major tectonic boundary. The obtained age results imply that different allochthonous metamorphic terranes were assembled along the collisional zone of the East African–Antarctica Orogen during the period from 650 to 500 Ma.

DOI： 10.1086/679468

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1086/675665

Language：Japanese   Publishing type：Research paper (scientific journal)  

  The Yatsushiro area in Kyushu Island, southwest Japan, forms the western tip of the Kurosegawa tectonic belt. This area is underlain by a serpentinite melange with complicated tectonic block assemblage of granitic rocks, high-temperature (HT)-type metagabbro (Grt-Cpx granulite, Grt-amphibolite and Cpx-bearing amphibolite), and high-pressure (HP)-type metagabbro (Jd-Gln rock and Gln-bearing metagabbro). The granitic rocks and the gabbros are the protoliths of the HT-type metagabbro (HT-gabbro), and supposed to be derived from volcanic arc at an active continental margin based on their major, trace, and rare earth element (REE) chemistry, while geochemistry of the gabbro protoliths of the HP-type metagabbro (HP-gabbro) indicates mid oceanic ridge basalt (MORB)-like precursors. The laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U-Pb dating of the granitic rocks and the HT-gabbro gave the Ordovician magmatic ages (∼ 450 Ma). On the other hand, the HP-gabbro showed the igneous age of the Late Cambrian (∼ 490 Ma). Similar rock suites collected from the Kurosegawa tectonic belt in Shikoku and in the Kii-peninsula have the same chemical and age affinities according to their rock types. These results indicate the strong geological and tectonic similarities within the Kurosegawa tectonic belt. The similar assemblage is present in the South-Kitakami belt suggesting similarities in their origin.

DOI： 10.2465/gkk.131126

Language：English  

「割山圧砕花崗閃緑岩」は，阿武隅山地東縁の双葉断層に沿い，その東側に南北に細長く分布する岩体である．全岩化学組成の特徴から典型的なアダカイトと判断されるが，中粒でよりK₂O，Srに乏しい系列と，粗粒でそれらに富む系列に2分される．前者から308 ± 3，302 ± 4 Maの，また後者から118 ± 2，117 ± 1 MaのジルコンU–Pb年代が得られた．このことから，後期石炭紀のものを従来にならい割山花崗岩体，前期白亜紀のものをあらたに高瀬花崗岩体と命名した．300 Ma頃の年代を示す花崗岩は，これまで日本列島からほとんど見つかっていなかった．今回の発見により，これまでペルム紀（約280 Ma）とされてきた日本列島の後期古生代花崗岩の形成開始年代は，後期石炭紀の300 Maまで遡ることになる．またその花崗岩がアダカイト質花崗岩であることから，300 Ma頃に始まる花崗岩形成は，海嶺沈み込みあるいは若いプレートの沈み込みで始まった可能性が指摘できる．

DOI： 10.5575/geosoc.2014.0003

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.gr.2013.04.001

Language：English   Publishing type：Research paper (scientific journal)  

Metamorphic rocks in the central part of Sør Rondane Mountains, eastern Dronning Maud Land, East Antarctica, are classified into three types based on petrological characteristics. (i) The Austkampane area preserves c. 800oC and 0.5-0.6 GPa peak metamorphic conditions followed by decompression and subsequent isobaric cooling and later hydration (A-type). (ii) The Brattnipene and eastern Menipa area preserve peak P-T conditions of c. 800oC and 0.7- 0.8 GPa with subsequent isobaric cooling and later hydration (B-type). (iii) The area including Lunckeryggen, southern Walnumfjella and western Menipa preserves an amphibolite-facies peak metamorphic condition with signatures of prograde metamorphism (L-type), which are typically unaffected by the retrograde hydration event. Peak granulite-facies metamorphism of A- and B-type rocks are contemporaneous at c. 640-600 Ma, but a difference in the P-T paths between these rocks can be explained by thrusting of the A-type rock unit onto the B-type rock unit. By contrast, the timing of the metamorphism of the L-type rocks is significantly younger at c. 550 Ma, possibly related to the intrusion of pegmatites and granitoids. These metamorphic records in the central part of the Sør Rondane Mountains can be a test ground for the regional tectonic processes proposed for the orogeny related to Gondwana formation. © The Geological Society of London 2013.

DOI： 10.1144/SP383.4

Language：English   Publishing type：Research paper (scientific journal)  

A possible armalcolite pseudomorph has been identified in garnet-sillimanite gneiss from Skallevikshalsen, located c. 30 km NE of Rundvågshetta, in a terrane with the highest metamorphic grade in the Lützow-Holm Complex, East Antarctica. It occurs as an Fe-Mg-Ti compositional domain consisting of ilmenite, rutile and pseudorutile, partially mantled by rutile within ilmenite. The domain yields an average XMg of 0.171±0.036 exceeding by 3 wt% TiO2from armalcolite stoichiometry, while the analysis closest to armalcolite stoichiometry has an XMgvalue close to 0.202. Host ilmenite with 0.4 mol% hematite is in contact with prismatic sillimanite, quartz, plagioclase and K-feldspar. In run products of annealing experiments performed to investigate the origin of the pseudomorph, armalcolite-ilmenite reaction coronae were developed around relict rutile in rock fragments of quartz eclogite from the Higashi-Akaishi mass of the Sanbagawa belt, central Shikoku, Japan. The experiments were carried out at 1 atm and 960-1050°C with wü stite-magnetite buffer and imply a minimum temperature of 1290°C for armalcolite stability when extrapolated to Skallevikshalsen pressures of 1.0 GPa. Mineral chemistry thermobarometry for Skallevikshalsen yields a metamorphic path with P-T peak conditions of 0.88-1.1 GPa and 970-1050°C, followed by retrograde metamorphism at 0.6 GPa and 780°C, and finally metasomatic alteration at c. 630°C. This P-T path matches that for similar ultrahigh-temperature metamorphic rocks from Rundvågshetta and Sri Lanka, and is markedly lower in temperature than the unreasonable estimates based on armalcolite stability. This discrepancy is inferred to reflect chemical impurities in armalcolite that lower its minimum temperature stability by more than 200°C. © The Geological Society of London 2013.

DOI： 10.1144/SP383.2

Language：English   Publishing type：Research paper (scientific journal)  

The Sør Rondane Mountains of eastern Dronning Maud Land, East Antarctica can be subdivided into two different crustal terranes: the NE-terrane and the SW-terrane. The former is underlain by basement rocks of amphibolite-facies (unit A) and granulite-facies (unit B), and the latter by granulite-facies (unit C) to greenschist-facies (units D and D') rocks. The metamorphic evolution of the NE-terrane exhibits a clockwise pressure-temperature-time (. P-T-t) path and the SW-terrane exhibits a counter-clockwise P-T-t path, and detrital zircon U-Pb ages are also different between the two terranes. The differences in the metamorphic evolution processes and detrital zircon provenance in these two regions can be explained by the collision of the NE-terrane and the SW-terrane which is constrained to have occurred at 600-650. Ma. The collision is interpreted to reflect convergence between the East Maud-East African orogen terrane and the Maud-Nampula terrane of the Kalahari Craton, which are bounded by the Main Tectonic Boundary and passes through the Sør Rondane Mountains. The RTP magnetic anomalies suggest this suture is cut by the subsequent collision boundary between the Kalahari Craton and the Rayner Belt, which is exposed in the Lützow-Holm region. This collisional belt is considered to have formed at approximately 520-580. Ma. © 2013 Elsevier B.V.

DOI： 10.1016/j.precamres.2013.05.017

Language：English   Publishing type：Research paper (scientific journal)  

The Sør Rondane Mountains in East Antarctica preserve two stages of tectonothermal events, at c. 650-600. Ma and c. 560-550. Ma, each of which is also widely preserved elsewhere in Gondwana within tectonic suture zones/orogens, although both ages of tectonothermal events are only rarely documented together in these other parts of Gondwana. A geochronological and petrogenetic study of highly retrogressed garnet-sillimanite-biotite-bearing pelitic gneiss, along with three generations of associated sub-concordant to discordant leucocratic felsic veins, which together are exposed in the southern Austkampane area in the central part of the Sør Rondane Mountains, provides important new constraints on the geological and age relationships between these two regional tectonothermal events. U-Pb SHRIMP dating of zircon grains isolated from the host garnet-sillimanite-biotite gneiss yields at least four distinct zircon age populations of c. 2800-720. Ma, c. 700. Ma, 640-630. Ma, and ~500. Ma. Chondrite-normalized REE patterns indicate that a pooled age of 637. ±. 6. Ma represents the timing of recrystallization of metamorphic HREE-depleted zircon, during which the zircon was in equilibrium with garnet. The earliest emplaced leucocratic vein (LV-1), which is partly intermingled with the host garnet-sillimanite-biotite gneiss (and enclosing garnet-bearing pelitic enclaves), contains a population of zircon grains that yielded a crystallization age of 635. ±. 4. Ma, which is almost identical to the age of zircons found within the host pelitic gneiss. The second-generation leucocratic vein (LV-2) occurs as a part of a set of sub-concordant veins/leucosomes comprising mostly biotite and muscovite. Although these particular leucosomes do not contain any zircon, they were found to contain abundant monazite, which yielded U-Pb ages of 640-630. Ma along with some older (relict) ~700. Ma ages. The third-generation leucocratic vein (LV-3) was sampled from a suite of pegmatitic veins that discordantly crosscut both the host pelitic gneisses and the older two sets of leucocratic veins. These third-generation veins contain magmatic zircons that exhibit HREE-enriched patterns typical of magmatic zircon crystallization, and which yielded a crystallization age of 550. ±. 3. Ma. The data imply that a major high-grade metamorphic event (possibly at granulite facies) took place in this region along with a subsequent late-stage re-hydration event, all within a relatively narrow time interval of <10. m.y. at ~635. Ma. A subsequent hydration event that took place much later on is recorded by the intrusion of a suite of discordant pegmatitic veins at ~550. Ma that are observed to crosscut and alter both the pre-existing pelitic gneiss and the other two older sets of felsic veins. These two ages of tectonothermal events in East Antarctica are coeval with the two major stages of Gondwana assembly. Hence, these results provide new insights into the development of metamorphic-fluid regimes within these major continent-transecting Neoproterozoic orogens. © 2012 Elsevier B.V.

DOI： 10.1016/j.precamres.2012.12.002

Language：English   Publishing type：Research paper (scientific journal)  

In order to understand the tectonic evolution of the Sør Rondane Mountains, eastern Dronning Maud Land, East Antarctica, sensitive high resolution ion microprobe (SHRIMP) U-Pb zircon dating and electron probe micro analyzer (EPMA) U-Th-Pb monazite dating were carried out on igneous rocks and metamorphic rocks whose P. T conditions have been well-constrained. Metamorphic rocks from northern part of Austkampane area recording a clockwise P. T path yield 600-640. Ma as the timing of peak granulite-facies metamorphism and 550-570. Ma for subsequent retrograde metamorphism. The same age relations were obtained from the metamorphic rocks from Brattnipene and eastern Menipa areas recording an anti-clockwise P. T path. Contemporaneous peak metamorphism with contrasting P. T paths can be explained by thrusting up (obduction) of the unit showing a clockwise P. T path onto the unit showing an anti-clockwise P-T path at ca. 660-640. Ma, which is considered to be the main metamorphic event. Metamorphic rocks from Lunckeryggen, southern Walnumfjella and western Menipa areas that preserve amphibolite-facies peak metamorphic conditions and are unaffected by the retrograde hydration, yield ca. 550. Ma. Ages of 500-550. Ma were also obtained on igneous rocks distributed throughout the whole area. Based on the close age relation between metamorphism of amphibolite-facies rocks and igneous activity, it is likely that metamorphism at ca. 550. Ma was caused by emplacement of voluminous igneous bodies. These precise correlation of metamorphic evolution and age would provide strong constraints on the construction of a tectonic model for Gondwana amalgamation. © 2012 Elsevier B.V.

DOI： 10.1016/j.precamres.2012.11.011

Language：English   Publishing type：Research paper (scientific journal)  

In this paper we clarify the history of deformation in the Sør Rondane Mountains (SRMs), eastern Dronning Maud Land (DML), East Antarctica, and construct a form-line contour map of the metamorphic and plutonic rocks in order to comprehend their structural features and provide constraints on the collisional tectonics of East and West Gondwana. We divide the deformational history in the SRMs into 13 stages (D1-D13). The tectonic regime varied frequently from extension (D3-D4) to layer-normal compression and layer-parallel extension (D5), to compression (D6), extension (D7), sinistral transtension and sinistral strike-slip (D8), compression (D9-D11), and finally extension related to dextral shearing (D12-D13). D7 and D8 indicate major extensional tectonic activity in the southern part of the East African and Antarctic Orogen (EAAO) before the Pan-African compressional event, and after the c. 600. Ma peak of metamorphism. The Pan-African compressional event resulted in the formation of upright folds with horizontal axes that curve along the coastline in central to eastern DML during the D9 deformation that took place between 600 and 560. Ma. The coastline-parallel fold axes and subvertical axial-planes correspond to the X-axes and the XY-planes, respectively, of strain ellipsoids that were progressively rotated counterclockwise toward the central parts of a sinistral shear zone. Therefore, the curved fold axes and axial-planes suggest the EAAO acted as a zone of sinistral transpression during the collision of parts of East and West Gondwana. Around 560-550. Ma, during D12, parallel dyke swarms of granitic pegmatite were intruded along normal faults under a regime of NNE-SSW horizontal extensional stress. The extensional paleo-stress and its related structures suggest dextral rather than sinistral shearing took place along the north-trending EAAO during this late Pan-African event. There is the possibility of a reversal of trans-orogen asymmetry from sinistral to dextral in the southern part of the EAAO. The dyke swarms are considered to have been the heralds of the voluminous 530-500. Ma A-type granite intrusions in DML. At the same time, the Lützow-Holm Complex was under a non-extensional tectonic regime, and may have been situated in a different orogen from the EAAO. © 2013 Elsevier B.V.

DOI： 10.1016/j.precamres.2013.05.010

Language：English   Publishing type：Research paper (scientific journal)  

This paper provides a detailed analysis of the geological evolution of the southern Austkampane region in the Sør Rondane Mountains, Antarctica, using geological and petrographical observations, geochemical, geochronological, radiogenic, and stable isotopic data, and metamorphic petrological techniques. The study area is dominated by felsic gneisses intercalated with mafic and carbonate rocks. Carbonate rocks include several calc-silicate and mafic to ultramafic blocks with carbonatite-like characteristics. The new data presented here indicate the presence of five important thermal events in the geological history of the region, at c. 1060, 770-750, 655-635, 560-545, and <545Ma. The c. 1060Ma event is characterized by granitic volcanic arc magmatism, possibly in an active continental margin setting, involving magmas that may have been sourced from enriched mantle formed by subduction of older crustal material during the formation of Rodinia. The oldest T(DM)age for this suite is 3.4Ga. The 770-750Ma event is characterized by both mafic and felsic magmatism in an active continental margin setting, with magmas being similar to bulk earth composition. The 655-635Ma thermal event is represented by granulite-facies metamorphism along an anticlockwise pressure-temperature path, involving heating of the lower crust at a continental margin, and subsequent obduction of a cratonic counterpart during collision. Granitic and basaltic magmatism at 560-545Ma is also associated with retrograde metamorphism and hydration-related partial melting of marble. The carbonate melt, and granitic and basaltic magmas during this event coexisted with each other and formed metasomatic calc-silicates and hornblendites, respectively. The final event at <545Ma is characterized by the intrusion of an undeformed quartz syenite dyke, which may be related to either (1) collision and melting of preexisting lower crustal material, or (2) melting of slightly enriched mantle material in an extensional tectonic setting following the earlier collisional event. The five thermal events between c. 1100 and 500Ma recognized in this study from a narrow region of the Sør Rondane Mountains, suggest that a combination of geochronological, whole-rock, and isotope geochemical analyses of metamorphic rocks and the pressure-temperature evolution could constrain the processes that operated during the amalgamation and break-up of Rodinia and the formation of Gondwana. A similar approach is essential in neighboring Gondwana terranes for modeling the protracted events of Neoproterozoic orogenesis. © 2012 Elsevier B.V.

DOI： 10.1016/j.precamres.2012.10.009

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2517/1342-8144-17.3.241

Language：English  

DOI： 10.2465/jmps.121019a

Language：English  

DOI： 10.2465/jmps.121022a

Language：English  

Language：Japanese  

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2465/jmps.121021a

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.lithos.2012.10.013

Language：English   Publishing type：Research paper (scientific journal)  

In this paper we provide evidence for a counterclockwise P-T path and isobaric cooling for metapelitic rocks from the Sør Rondane Mountains, eastern Dronning Maud Land, East Antarctica. The counterclockwise path was determined using the following mineral textures and relationships: (1) garnet coronae on sillimanite where the sillimanite is associated with spinel in orthopyroxene-bearing granulite; (2) garnets that contain inclusions of spinel, sillimanite, and corundum, and where the sillimanite and corundum have sparse tiny spinel inclusions; (3) the garnet-orthopyroxene-plagioclase-quartz equilibria relationships using the contrasting compositions of high-Mg garnet - plagioclase inclusions and high-Ca garnet coronae - matrix plagioclase point to an increase in pressure. The peak metamorphic conditions were determined by thermobarometry and pseudosection analyses, and are consistently within the ranges 850-900°C and 8-9kbar. Orthopyroxene porphyroblasts close to garnet coronae have relatively high Al2O3contents (~6.1wt.%), consistent with the highest temperature conditions reported so far from the Sør Rondane Mountains. Prismatic subidioblastic staurolite formed as a secondary mineral along the margins of the garnets, and this retrograde staurolite indicates a back-reaction during isobaric cooling. The conditions for staurolite formation are taken to be 680-700°C and 8.5kbar using isopleths, and this is consistent with the appearance of secondary kyanite in the matrix. On the basis of the metamorphic P-T path and the tectonic setting of the precursor rocks, the following tentative scenarios can be inferred: (1) the heat source for the early sequence of metamorphism was derived from advective heat flow at an active continental margin, and (2) the subsequent increase in pressure was caused by overthrusting or obduction of either oceanic crust or oceanic island arc onto the Brattnipene region. These tectonothermal events took place along a possible proto-Gondwana margin at ca. 650-600Ma. © 2012 Elsevier B.V.

DOI： 10.1016/j.precamres.2012.10.002

Language：English   Publishing type：Research paper (scientific journal)  

This study is a detailed investigation of the petrology and geochronology of the Late Proterozoic metatonalite in the Sør Rondane Mountains, eastern Dronning Maud Land, Antarctica. Metatonalite is dominant over roughly 100×20km2area in the southwestern end of the mountain range and is classified into five lithologies: gneissose Bt-Hbl metatonalite, weak gneissose Hbl-Bt metatonalite, Hbl metagabbro, Hbl-Bt tonalitic gneiss, and Bt metatonalite. The gneissose Bt-Hbl metatonalite is the main lithotype widely distributed over this area, which is geochemically categorized as low-K tholeiitic granitoid. Petrological studies suggest that the tholeiitic magma was derived from low-K basalt melting at the crustal depth, and the most plausible tectonic setting is a juvenile oceanic arc. The other four metaplutonic rocks are scattered as stocks or small intrusions in this area. They are geochemically regarded as calc-alkaline adakites related to oceanic slab melting. U-Pb SHRIMP zircon ages of the tholeiitic metatonalite are concentrated at 998-995Ma, whereas the calc-alkaline adakitic rocks are younger and divided between ages 945-920Ma and 772Ma. We believe that the tholeiitic metatonalite was formed first as a juvenile arc component between 998 and 995Ma, followed by adakitic magmatism and oceanic slab melting at 945-920Ma and 772Ma. Magmatism during this stage is not recorded in the western to central Dronning Maud Land. Moreover, the exposure of an adakitic equivalent continues at the farther eastern side of the Sør Rondane Mountains. This suggests that the tectonic framework of the Sør Rondane Mountains, eastern Dronning Maud Land, is different from the western to central Dronning Maud Land. © 2012 Elsevier B.V..

DOI： 10.1016/j.precamres.2012.09.026

Language：Japanese  

Language：English  

脊振山地・浮嶽に産する泥質グラニュライトとその周囲の糸島花崗閃緑岩について，LA-ICP-MSジルコンU－Pb年代とFE-EPMAモナザイトU－Th－Pb年代を測定した．糸島花崗閃緑岩からはジルコンU－Pb法で102 ± 2 Maの火成年代が得られた．また，泥質グラニュライトのジルコンの縁辺部からは105 ± 2 MaのU－Pb年代が得られた．この年代は100－120 MaのモナザイトU－Th－Pb年代と調和的である．ジルコンの核部からは，400－510 Maに集中する砕屑性年代が得られ，最も若い年代は360 Maであった．この砕屑性ジルコンの年代分布は蓮華変成岩に類似するが，変成作用の時期や条件が異なる．浮嶽の泥質グラニュライトが示す変成年代は100－120 Maであり，肥後変成岩の再加熱の時期あるいは領家変成岩の主要な変成作用の時期とほぼ同時期である．しかし砕屑性ジルコンの年代分布が一致せず，これらの変成岩は互いに異なる後背地に由来することが考えられるため，直接の対比は困難である．

DOI： 10.5575/geosoc.2011.0022

Language：English   Publishing type：Research paper (scientific journal)  

This paper reports the first evidence of ultrahigh-temperature (UHT) metamorphism from the Sør Rondane Mountains, eastern Dronning Maud Land, East Antarctica, which is evident as orthopyroxene. +. spinel symplectite in an amphibolitized mafic granulite. The granulite consists of olivine, orthopyroxene, clinopyroxene, pargasitic amphibole, plagioclase, and ilmenite, and it possesses a within-plate alkali basalt signature. The local bulk chemical composition of symplectite, major and trace element compositions, and thermodynamic calculations for the symplectite, suggest the presence of garnet at the high-pressure stage and that the symplectite formed from garnet, olivine, and primary orthopyroxene by decompression from more than 12. kbar at 1000°C. The granulite records a subsequent amphibolite-facies overprint (<700°C at <6. kbar) that involved the chemical re-equilibration of several phases. The obtained pressure-temperature (P-T) conditions and P-T path are different from the UHT metamorphism from the Schirmacher Hills, central Dronning Maud Land, which is considered to have occurred in a back-arc tectonic setting. The relatively high-P conditions and the decompression path reconstructed in the present study are similar to those reported for southern India, Sri Lanka, and part of northeastern Mozambique, possibly reflecting continental thickening and exhumation during the main collision event between East and West Gondwana. © 2011 Elsevier B.V. and NIPR.

DOI： 10.1016/j.polar.2011.03.005

Language：Japanese  

茨城県多賀山地の日立変成古生層は，産出化石により前期石炭紀以降の地層とされてきた．しかし最近広範にSHRIMP年代が測定され，多賀山地に日本最古のカンブリア系が60 km²以上にわたって広く分布することが明らかになった．A班では，原岩構造のわかるカンブリア系のうち，枕状構造や発泡構造，急冷組織などがみられる火山岩を原岩とする赤沢層と，堆積構造を残す砂泥質堆積岩や礫岩を原岩とする西堂平層，さらに赤沢層に貫入するカンブリア紀花崗岩類を見学する．また，赤沢層を不整合で覆う石炭系大雄院層基底部の礫岩などを見学する．今後，これらの露頭は日本におけるカンブリア系の模式地となることが予想される．今回は当初の研究成果に基づくものであり，今後さらに多くの研究者によってより深く研究され，日本列島形成の初期の様子が明らかになるであろう．

DOI： 10.5575/geosoc.117.S1

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.1111/j.1440-1738.2011.00764.x

Language：English   Publishing type：Research paper (scientific journal)  

In this study, mafic granulite and related leucosomes from the Song Ma Suture zone in northern Vietnam were investigated. Euhedral garnet appears in both granulites and leucosomes, whereas the former is partly to mostly replaced by orthopyroxene + plagioclase symplectite. Most garnets occurring both in granulite and leucosome contain an Mg-rich and Ca-poor core as well as an Mg-poor and Ca-rich mantle. Garnets in leucosomes have an Mg-rich and Ca-poor thin rim. Amphibole + quartz association is observed only in the core and mantle and not in the rim and matrix. Garnet core is characterized by flat middle to heavy rare earth element (REE) patterns and depletion of light REEs. The rim also contains high concentrations of middle REEs, whereas light and heavy REEs are further depleted in comparison with the core. The REE patterns of the mantle are completely different from core and rim, which show considerable depletion in light to middle REEs and extreme enrichment in heavy REEs. The petrographical features and REE patterns of the associated mineral phases suggest that the complex chemical zonation of garnet might be formed by dehydration melting of amphibole and multiple recrystallization of garnet.

DOI： 10.2465/jmps.100620a

Language：Japanese  

&emsp;Hitachi metamorphic rocks located in the southern part of the Abukuma Mountains, Northeast Japan, distinctively contain meta-volcanic rocks and meta/sheared granitoids. The igneous ages of meta-granite and meta-porphyry from the Hitachi metamorphic rocks were determined by the SHRIMP zircon method. In this paper, we describe occurrence, petrography, and petrochemical characteristics of these studied rocks. Meta-porphyry, with an igneous age of 506 Ma, intrudes into the meta-volcanic rocks of the Akazawa Formation of the Hitachi metamorphic rocks and has a micrographic texture and a spherulitic texture of an igneous origin. Previous studies have already reported an igneous age of 491 Ma for meta/sheared granitoids using the SHRIMP zircon method. Cambrian meta/sheared granitoid samples occur widely as a granitic body in the northeastern part of the Hitachi metamorphic rocks. (A) Meta-granite of the same age (498 Ma) as the sample used for the above dating is found as boulders in meta-conglomerates. The meta-conglomerate, which is found in the Daioin Formation of the Hitachi metamorphic rocks, lies unconformably on a Cambrian meta-granite body. Both meta-volcanic rocks and meta/sheared granitoids have chemical characteristics commonly associated with island arc volcanism. As such, the Akazawa Formation is likely to have originated in the Cambrian era, although we have no SHRIMP age for meta-volcanic rocks of the Akazawa Formation.

DOI： 10.5026/jgeography.119.245

Language：English   Publishing type：Research paper (scientific journal)  

In the central Sør Rondane Mountains, East Antarctica, orthopyroxene felsic gneiss (OPG) was converted to hornblende-biotite felsic gneiss (HBG) by hydration that accompanied the intrusion of pegmatite. The retrograde HBG contains exsolved rutile in quartz. The composition of orthopyroxene and clinopyroxene in OPG suggests a temperature of 840 °C (interpreted as the near-peak temperature), and the composition of hornblende and plagioclase in HBG suggests a temperature of 670-700 °C (interpreted as the temperature during hydration). Ti concentrations in quartz were measured using an electron probe micro-analyzer, and Ti-in-quartz thermometers were applied. Measured Ti concentrations were 110 ppm (equivalent to 760-820 °C) for homogeneous quartz from OPG and 35 ppm (650-700 °C) for an exsolution-free area of a quartz grain from HBG. The pre-exsolution Ti concentration in quartz from HBG was reconstructed with 100 μm beam diameter and 25 kV of accelerating voltage, giving 103 ppm, similar to the value obtained for homogeneous quartz in OPG. The temperatures obtained using a Ti-in-quartz thermometer are consistent with those estimated using other thermometers. Although analysis of the main constitute minerals in HBG yields the conditions of hydration, the reconstructed pre-exsolution Ti content in quartz within HBG yields the pre-hydration conditions. Thus, the Ti-in-quartz thermometer is a potentially powerful tool with which to identify the peak or near-peak temperature conditions, even for retrogressed metamorphic rocks. © 2009 Elsevier B.V. and NIPR.

DOI： 10.1016/j.polar.2009.08.005

Language：Japanese  

第49次日本南極地域観測隊(JARE-49)夏隊・セール・ロンダーネ山地地学調査隊は,ドロンイングモードランド航空ネットワークを利用して航空機で日本から直接南極内陸山地に赴き,2007年11月23日～2008年2月5日の75日間,キャンプ生活を送りながらスノーモービルと徒歩によりセール・ロンダーネ山地中央部地域の地質学的野外調査を実施した.また,ベルギー基地,インド基地等を訪問し,国際交流を実施した.今回の野外調査は,航空機を利用した南極内陸地域野外調査の初の試みであり,2007年度にスタートした国際極年(IPY)とも連動した国立極地研究所の一般プロジェクト研究(課題番号P-5-1:代表・本吉洋一)の初年度調査でもある.本報告では,設営面での計画の立案・準備から実施経過に至る過程について詳しく述べる.The Sør Rondane Mountains field research party, part of the summer party of the 49th Japanese Antarctic Research Expedition (JARE-49), carried out geological field work in the central part of the Sør Rondane Mountains and improved international goodwill with Belgian, Indian and other national expeditions for 75 days from November 23, 2007 to February 5, 2008. The field party tried to access the Sør Rondane Mountains directly from Japan by using the Dronning Maud Land Air Network (DROMLAN), which is the first attempt at an Antarctic inland field survey just using an airplane through the 50 years of JARE history. This research expedition was linked together with the International Polar Year and also the first operation program of a research project of National Institute of Polar Research (No. P-5-1: leader, Y. Motoyoshi). This report gives the details on the operation planning and a summary of the fieldwork including logistics and weather report.

DOI： 10.15094/00009458

Event date： 2022.9

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：早稲田大学（新宿区）   Country：Japan  

Event date： 2021.11

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Event date： 2021.11

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Event date： 2021.9

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Event date： 2021.5 - 2021.6

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Event date： 2020.12

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Event date： 2020.12

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Event date： 2020.11 - 2020.12

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Venue：国立極地研究所，立川市およびオンライン   Country：Japan  

Event date： 2020.11 - 2020.12

Language：English   Presentation type：Oral presentation (general)  

Venue：国立極地研究所，立川市およびオンライン   Country：Japan  

Event date： 2020.11 - 2020.12

Language：English   Presentation type：Oral presentation (general)  

Venue：国立極地研究所，立川市およびオンライン   Country：Japan  

Event date： 2019.11 - 2019.12

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Event date： 2019.11 - 2019.12

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Event date： 2019.11

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Event date： 2019.9

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Event date： 2019.9

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Event date： 2019.9

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Event date： 2019.5

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Event date： 2018.10

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Event date： 2018.9

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Event date： 2018.5

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Event date： 2017.9

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Metamorphic process of the Tromso Nappe in the Scandinavian Caledonides based on P-T-t history of felsic gneiss

Event date： 2016.9

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Event date： 2016.9

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Event date： 2016.9

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Event date： 2016.9

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Event date： 2016.5

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LA-ICP-MS Zircon U-Pb ages for metamorphic rocks from the Highland and Wanni Complexes, Sri Lanka

Event date： 2015.9

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Event date： 2015.9

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Event date： 2015.9

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Event date： 2015.9

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Event date： 2015.7

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：東京学芸大学   Country：Japan  

Event date： 2014.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：福岡大学   Country：Japan  

Event date： 2014.11

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Venue：福岡大学   Country：Japan  

Event date： 2014.9

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Event date： 2014.9

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Event date： 2014.9

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Event date： 2013.9

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Metamorphic evolution of South Sulawesi, Central Java, and South Kalimantan in Indonesia

Event date： 2013.9

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Event date： 2013.9

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Event date： 2011.9

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Petrology and geochronology of pelitic gneisses in the Hanhohiyn Mountains, the northwestern part of Mongolia
Hanhohiyn Mountains is located in the northwestern part of Mongolia. The mountains are mainly composed of marble, meta-quartzite and pelitic gneisses intercalating with lenticular garnet-amphibolite, garnet-orthopyroxene gneiss and so on. Pelitic gneisses are classified into garnet-sillimanite-biotite gneiss, garnet-cordierite-biotite gneiss and garnet-biotite gneiss. These gneisses indicate the peak metamorphic condition of 600-700 degree and 5.5-6 kbar accompanied by decompression. The EPMA U-Th-Pb Monazite ages concentrate between 480-510 Ma which is interpreted as the timing of the peak metamorphism.

Event date： 2011.9

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黒瀬川構造帯は，九州～関東山地にわたり，蛇紋岩メランジ帯として断続的に分布する．黒瀬川構造帯の構成岩類のなかでも，低温高圧型変成岩である青色片岩は，広域的に分布することが報告されている．本研究では，黒瀬川構造帯の九州・五木村，四国中部・円行寺，四国東部・勝浦，紀伊半島東部・鳥羽に産する青色片岩を調査し，さらに黒瀬川構造帯の青色片岩と比較するため，八重山変成岩類である沖縄・石垣の青色片岩の調査を行った．ここでは，上記各地の青色片岩について，岩石記載および全岩化学組成の比較を報告する．

Event date： 2011.9

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中央アジア造山帯は原生代後期から中生代にかけて形成された巨大な造山帯で，複数回の沈み込み帯や衝突帯から構成される．モンゴルはこの中央アジア造山帯の中心に位置し，地質学的に重要な位置を占める．本論文では，西モンゴルの火成活動史を報告し，火成作用とテクトニックセッティングの関係を述べる．

Event date： 2011.9

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モンゴル・アルタイ山脈に分布する高Al-Mg片麻岩について，記載岩石学的，鉱物化学的，地球化学的，年代学的解析を行った．

Event date： 2011.9

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Garnet, Clinopyroxene megacrysts and Garnet-bearing mantle xenoliths from the Tariat Depression, Mongolia

Event date： 2011.9

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Stable isotope study of metacarbonate rocks from western Mongolia : Implications for fluid-rock interaction processes in the Central Asian Orogenic Belt

Event date： 2011.9

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Paleozoic subduction and collision magmatism in west Mongolia : Evidence from geochronology and geochemistry of the intrusive rocks

Event date： 2010.9

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タイ西部・インタノン帯の広域的な年代測定を実施し，複数回の変成・火成作用の存在が明らかとなった．

Event date： 2010.9

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Event date： 2010.9

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Event date： 2010.9

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Event date： 2010.9

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Event date： 2010.9

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Event date： 2010.9

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Event date： 2010.9

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東南極ドロンニングモードランドにおけるゴンドワナ超大陸形成期の大陸衝突帯について，変成作用および重力モデルから解析した．

Event date： 2010.9

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Event date： 2010.9

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Event date： 2010.9

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Event date： 2010.4

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Event date： 2010.4

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Event date： 2010.4

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Event date： 2010.4

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Event date： 2007.9

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東南極セールロンダーネ山地に広域的に分布する苦鉄質変成岩類の化学組成により原岩構成に基づき帯区分され，NW-SE方向に帯状配列するA～D帯とENE-WSW方向のE～G帯である． A～D帯の最高変成条件は，約８kbar，900℃が見積もられ，メソパーサイト，転移ピジョン輝石などの超高温変成作用の痕跡もみとめられる．これらの中で，昇温期変成作用の痕跡を残すザクロ石中の残留藍晶石・十字石はA～C帯のみに見出され，後退変成過程では珪線石安定領域から紅柱石の安定な条件に至る．D帯では後退変成作用時に２次的生成された藍晶石−黒雲母−石英共生がみとめられる．一方E～G帯では緑色片岩相から珪線石や十字石−石英共生が安定な角閃岩相の変成条件しか見出されず，後退変成過程で紅柱石が生成されている．これらの３つの異なる変成過程は， SRS形成時の大陸衝突にともなう衝突型変成作用の進行過程で形成されたことが考えられる．

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Language：Japanese   Presentation type：Oral presentation (general)  

Venue：国立極地研究所   Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Country：United States  

Language：English   Presentation type：Oral presentation (general)  

Country：United States  

Language：English   Presentation type：Oral presentation (general)  

Country：United States  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：国立極地研究所   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：幕張   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：北海道大学   Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：秋田大学   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：秋田大学   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：秋田大学   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：秋田大学   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：秋田大学   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：秋田大学   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：秋田大学   Country：Japan  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：秋田大学   Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Venue：Dali   Country：China  

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：国立極地研究所   Country：Japan  

Language：English   Presentation type：Oral presentation (general)  

Venue：国立極地研究所   Country：Japan  

Event date： 2010.9

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Country：Other  

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Language：Japanese   Publishing type：Internal/External technical report, pre-print, etc.  

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Retrograde metamorphic P－T paths of garnet—pyroxene—bearing mafic gneisses from the Brattnipene nunataks in Sør Rondane Mountains, East Antarctica, were examined. The majority of samples preserve irregular—shaped garnet coexisting with clinopyroxene, quartz and plagioclase that developed around magnetite, ilmenite and orthopyroxene. The garnet contains fine—grained worm—like quartz inclusions. The occurrences are common in other mafic gneisses in northern Brattnipene and are interpreted as isobaric cooling textures. In another sample, garnet porphyroblasts have been replaced by symplectites of fine orthopyroxene and plagioclase. The mineral textures indicate near isothermal decompression. Retrograde P－T conditions estimated from rock containing orthopyroxene—plagioclase symplectite are within the range of 6.5 ~ 7.2 kbar, 700 ~ 780℃. Previous reports have revealed that metamorphism around Brattnipene is characterized by counterclockwise P－T path involving near—isobaric cooling. Our new finding suggests that metamorphic rocks formed by isothermal decompression should be present at higher altitude in the Brattnipene or relevant nunataks.

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本稿では、ジルコンの迅速分離手法とLA-ICP-MSを用いたU-Pb年代測定の実例を報告する。ジルコンは岩石中には副成分鉱物として産するため、その量的な問題から多くの場合、試料からの分離が必要となる。ジルコンの分離には、現在においても重液を用いた分離法が一般的である。しかしながら、重液の使用に対する非効率性や人体に及ぼす危険性、高コストが指摘されてきた。そこで、小論ではこれらの問題を解決するために、重液を用いないジルコンの迅速分離手法を考案した。本手法では、粉末試料をビーカーや時計皿による水簸および椀掛けをすることでジルコンを30分以内に抽出することが可能であり、重液分離と比べると極めて迅速で効率よく、低コストで安全な手法といえる。ジルコンはU-Pb年代測定のほかに、包有物解析や化学組成から様々な地質事変を制約できる鉱物である。本手法は膨大なジルコン分析に対応した地質学的研究に非常に有用な手法であるとともに考古学などの他分野への応用も期待される。This report provides the rapid separation techniques of zircons and an example of U-Pb dating of the zircons using LA-ICP-MS. Zircons have been commonly separated from a sample using heavy liquid. However, previous reports have pointed out the inefficiency, harmful effect and high cost of the heavy liquid method. In this report, we provide the rapid techniques for zircon separation without using heavy liquid, and procedures just before zircon analysis, including separation, hand picking, mounting, and observation under cathodoluminescence image. In the method introduced here, the zircons can be separated only for 30 minutes per one sample just by panning with a beaker and watch glass. Therefore, this method is more efficient, quicker, lower cost and safer compared with heavy liquid separation.

DOI： 10.15017/1456056

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変成鉱物中の細粒包有物は, 多くの場合包有する変成鉱物の成長時に取り込まれることによって形成される. したがって, 細粒包有物の同定・解析は, 変成作用の過程を明らかにする上で有用である. しかし, これまで鏡下観察や電子プローブマイクロアナライザーによる表面分析では, 細粒包有物は充分に同定できない場合があった. 本稿では, この問題を克服するために, 九州大学大学院比較社会文化研究院地球変動講座に設置されているデジタルマイクロスコープと顕微ラマン分光分析装置を用い, 多数の微細包有物を解析する多深度解析手法を確立した. この手法では, 1μm間隔で撮影した鏡下写真とそれらの合成画像から, 包有物の三次元位置, 形状, 粒径, 色を迅速に明らかにすることができる. また, 形態による分類と包有された位置を元に, 顕微レーザーラマン分光分析装置を用いてすべての種類の包有物が同定可能である. 本手法は, 岩石学的研究はもとより, 透明物質中の内部包有物や不純物を扱う他分野にも応用できるものである.Fine-grained inclusions in metamorphic minerals are generally regarded to be trapped during the growth of the host metamorphic minerals. It suggests that identification and analyses of the each fine-grained inclusion are quite important in understanding each metamorphic evolution. However, identification and confirmation of the each inclusion phase are often difficult using conventional methods such as optical microscope observation and surface analysis by an electron microprobe analyzer. In this paper, we introduce a new analytical technique, named multi-depth analyses, to rapidly identify very fine-grained inclusions in metamorphic minerals using digital microscope and laser Raman microspectroscopy installed at Department of Environmental Changes, Faculty of Social and Cultural Studies, Kyushu University. Using this technique, three-dimensional position, shape, grain size and colors of fine-grained inclusions are distinguished easily by the multi-depth composite image in 1μm depth interval. The minerals or fluid inclusions are identified by the obtained Raman spectra even if the inclusions are quite fine-grained (≃1μm) or are situated in deeper position in thin section. This technique should be useful not only for petrological studies, but also for the other studies, e.g., archaeology, using inclusions or impurities in non-opaque matrix.

DOI： 10.15017/26212

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Late Proterozoic juvenile arc metatonalite and adakitic intrusions in the Sor Rondane Mountains, East Antarctica

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DOI： 10.14824/jakoka.2011.0.99.0

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Paleozoic igneous activities in south-central Mongolia

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Metamorphic Evolution of High-Pressure Metamorphic Rocks from Bantimala and Barru Complex in South Sulawesi, Indonesia

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This report provides analytical techniques for major, trace and rare earth elements by X-ray fluorescence spectrometry (XRF) and laser ablation-inductively coupled plasma-mass spectrometry (LAICP-MS) at Department of Environmental Changes, Faculty of Social and Cultural Studies, Kyushu University. Totally 42 elements can be measured from low dilution glass bead (sample:flux ratio of 1:2). 23 elements (SiO_2, TiO_2, Al_2O_3, total Fe_2O_3, MnO, MgO, CaO, Na_2O, K_2O, P_2O_5, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb and Ba) of each sample were measured in 80 minutes by XRF. The other 19 elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, Pb, Th and U) were later measured in 5 minutes by LA-ICP-MS. Synthetic samples prepared from pure chemical reagents as well as standard samples provided by Geological Society of Japan (GSJ) (20 samples) were used to define individual calibration lines for XRF analysis, and SRM612 glass standard issued by the National Institute of Standard and Technology (NIST) was used as the calibration standard for LA-ICP-MS analysis. Analytical results of the GSJ standard samples appear an agreement with their recommended values mostly within 15% differences. The system can provide abundances of the most elements in rocks, and requires only 1.8g of sample powder, hence it should be very useful not only for geological but also for archeological samples.

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Garnet, Clinopyroxene megacrysts and Garnet-bearing mantle xenoliths from the Tariat Depression, Mongolia

DOI： 10.14824/jakoka.2011.0.100.0

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Stable isotope study of metacarbonate rocks from western Mongolia : Implications for fluid-rock interaction processes in the Central Asian Orogenic Belt

DOI： 10.14824/jakoka.2011.0.101.0

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High-Al-Mg gneisses and related rocks from the Mongolian Altay Mountains

DOI： 10.14824/jakoka.2011.0.99.0

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モンゴル・タリアットに産するザクロ石，単斜輝石巨晶と含ザクロ石マントルゼノリスについて，発表する

DOI： 10.14824/jakoka.2011.0.100.0

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DOI： 10.14824/jakoka.2010.0.202.0

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DOI： 10.14824/jakoka.2010.0.173.0

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DOI： 10.14824/jakoka.2010.0.207.0

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DOI： 10.14824/jakoka.2010.0.181.0

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DOI： 10.14824/jakoka.2010.0.221.0

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DOI： 10.14824/jakoka.2010.0.203.0

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DOI： 10.14824/jakoka.2009.0.15.0

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DOI： 10.14824/jakoka.2009.0.89.0

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DOI： 10.14824/jakoka.2009.0.43.0

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DOI： 10.14824/jakoka.2009.0.57.0

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DOI： 10.14863/geosocabst.2008.0.260.0

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DOI： 10.14863/geosocabst.2008.0.265.0

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DOI： 10.14863/geosocabst.2008.0.264.0

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DOI： 10.14863/geosocabst.2008.0.263.0

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DOI： 10.14863/geosocabst.2008.0.262.0

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DOI： 10.14863/geosocabst.2008.0.261.0

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DOI： 10.14863/geosocabst.2007.0.81.0

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DOI： 10.14824/jakoka.2007.0.225.0

Audience： General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture