担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Journal of Asian Earth Sciences  

The genesis and tectonic controls on the emplacement of post-collisional granites in the Karakoram Block (KB) in northern Pakistan are unclear due to lack of detailed studies. Zircon U-Pb dating indicates that the Sumayar pluton was emplaced at ∼ 9.6 Ma and represented one post-collisional magmatism. The Sumayar granite samples belong to strong peraluminum granites with aluminum saturation indexes of 1.1–1.2. Zircons from the granite exhibit strong negative εHf(t) values mostly of between −30 and −25, indicating a supracrustal source. Whole-rock geochemical data display enrichment in light rare earth elements and large ion lithophile elements, depletion in high field strength elements, and strong negative Eu anomalies. The low CaO/Na2O ratios and high Rb/Sr ratios together with the presence of tourmaline, suggest that the primary magma was formed from dehydrating melting of B-rich metapelites at moderate temperature conditions. In comparison with other post-collisional S-type granites in the KB, two groups were recognized. The first group represented by the Baltoro granite and other granites of ca. 36–15 Ma, is volatile-depleted and B-deficient, and formed from partial melting of greywacke source. The second group represented by the Sumayar granite and other small plutons of 9.6–3.0 Ma, formed from dehydration melting of B-rich metapelitic source. The emplacements of these S-type granitoids are attributed to the episodic partial melting of accretionary wedge rocks and associated crustal anatexes, due to the heat generation during the post-collisional stage at the hanging wall along the collisional boundary between the Kohistan Island Arc and the Asian Plate.

DOI： 10.1016/j.jseaes.2024.106053

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Lithos  

Granitoids at subduction zones play a significant role in the generation and evolution of continental crust. The Kohistan Batholith in the Kohistan Island Arc is, in large part, comprised of granitoids with various sizes, amongst which the Matum-Das tonalitic pluton stands out as the most enigmatic due to its emplacement age and unique geochemical signatures. The genesis and formation mechanism of the Matum-Das tonalite is still unclear. In addition, the Matum-Das tonalite hosts abundant mafic microgranular enclaves (MMEs), which have rarely been mentioned in previous studies. Here, a combined investigation of the petrological characteristics, mineral chemistry, zircon U[sbnd]Pb geochronology and Hf isotope, whole-rock major, trace element and Sr[sbnd]Nd isotope geochemistry has been conducted on the Matum-Das tonalite and the MMEs. Zircon U[sbnd]Pb dating indicates that the Matum-Das tonalite was emplaced at ∼150 ± 2 Ma, comparable with the age of the MMEs (∼149 ± 1 Ma). The consistent isotopic signatures of the host tonalite (ISr = 0.7046∼–0.7053; εNd(t) = +6.0 ∼ +7.8; εHf(t) = +13.9 ∼ +18.0) with the MMEs (ISr = 0.7034∼–0.7048; εNd(t) = +6.6 ∼ +9.4; εHf(t) = +11.2 ∼ +20.4) indicate the same parental magma source, which was mainly derived from the depleted mantle. The tonalite displays highly acidic signatures with SiO2 contents ranging from 73.72 to 76.06 wt% and low alkali (Na2O + K2O) contents of from 3.62 to 5.04 wt%. It has low Sr and high Y contents with low Sr/Y ratios. Compared to the host tonalite, the MMEs are dioritic in composition and have metaluminous affinity. Combined with the non-adakitic traits and high-water contents (9.07–11.68 wt%) inferred from the amphibole chemistry, we propose that the Matum-Das tonalite was most likely formed by fractional crystallization of hydrous magma derived from the metasomatized asthenosphere mantle. The associated MMEs were formed in the earlier stage of magma evolution from the same parental magma. The onset of intra-oceanic subduction of the Neo-Tethys Ocean in the late Jurassic is responsible for the island arc volcanism. The studied tonalitic rocks yielded the oldest ages within the KIA, and they represented the magmatic products in the initial stage of the Neo-Tethys intra-oceanic subduction.

DOI： 10.1016/j.lithos.2024.107535

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：International Geology Review  

The Jijal Complex is considered one of the largest Neo-Tethyan remnants in the intra-oceanic Cretaceous–Palaeogene Kohistan Arc of Pakistan. This complex largely consists of gabbros, peridotites, and chromitites. Previous studies documented the genesis of gabbros and chromitites in detail; however, detailed geochemistry and magma genesis were lacking. In this investigation, we present whole-rock geochemical and platinum group elements (PGEs) data of Jijal peridotites (dunites and harzburgites). The objectives of this study are to elucidate magmatic processes and tectonic regimes involved in the formation of peridotites, factors influencing the concentration and dispersion of PGEs in them, and their tectonic evolution. The investigated peridotite samples are depleted in magmaphile major elements (Al2O3: 0.23–0.57, TiO2: 0.01–0.04, and CaO: 0.08–0.69 wt%), relative to the primitive mantle values, reflecting melt-rock interaction during their magmatic evolution. In addition, rare-earth element (REE) contents in harzburgites are relatively higher compared to the dunites; however, both rock types exhibit depletion with respect to the chondrite-normalized values. The obvious negative anomalies of Nb, Zr, and enriched LREE and large ion lithophiles collectively substantiate their association with depleted arc-type mantle components, metasomatism, and melt/fluid-rock reactions after partial melting episodes. Bulk-rock and geochemical modelling of PGEs data of the peridotites suggest their shallow depth spinel-bearing depleted heterogeneous mantle source and generation from refractory mantle residuum along with boninitic signatures in a supra-subduction zone (SSZ). The PGE’s geochemistry additionally reveals that partial melting, fractionation, metasomatism, and sulphur under-saturation were the key factors that controlled the concentration and distribution of PGEs in the studied rocks. The boninitic features of the Jijal peridotites are equated with intraoceanic fore-arc followed by subduction initiation, and melt-rock reactions in a hydrated forearc mantle, indicating robust evidence of mantle depletion and pervasive refertilisation in an embryonic Neo-Tethyan arc system. Tectonically, the investigated rocks encapsulate vestiges of the Cretaceous Tethyan Ocean and record multifaceted history from boninitic to slab-proximal island arc affinity in compliance with an intraoceanic SSZ fore-arc regime coherent with the subduction inception.

DOI： 10.1080/00206814.2024.2318573

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Geology  

DOI： 10.1130/G51860C.1

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Acta Geochimica  

Enhanced weathering (EW) of ultramafic rocks from the Muslim Bagh Ophiolite, Pakistan, has been studied in laboratory experiments to explore carbon sequestration as a climate change mitigation strategy for coastal and open sea environments. The research focused on a cost-effective ex situ experiment to examine the effects of EW reaction pathways arising from the interactions among rock powder, seawater and CO2. The experimental filtrates from different milled peridotite samples exhibit a decrease in the Mg/Ca ratio as the specific surface area increases, which accelerates reaction rates. This suggests that the leached Mg from the original rock may have been consumed in the formation of brucite, serpentine and carbonates during EW. Similar reaction pathways are also responsible for the chemical alterations observed in amphibolite, albeit to varying degrees. On the other hand, the experimental residues showed an increase in loss on ignition compared to the original rock, indicating that EW has facilitated the incorporation of H2O and CO2 into secondary mineral structures through various reaction pathways, leading to the formation of brucite, serpentine and carbonates. Thermal gravimetric analysis of the experimental residues confirms the presence of these minerals based on their decomposition temperatures. Additionally, XRD analysis identified a range of carbonates in the residues of both peridotite and amphibolite samples, validating the occurrence of carbonation reactions. SEM images reveal textural changes in both samples, supporting the formation of secondary minerals through EW, consistent with observations from the petrographic study of untreated samples. Control experiments on CO2 absorption in seawater showed a decrease in pH, highlighting ocean acidification from increased CO2 emissions. However, when rock powder was added to the seawater-CO2 mixture, the pH increased. This suggests that the EW of ultramafic rock powders can sequester CO2 while raising seawater pH through the formation of secondary minerals. This research could serve as an analog for EW applications, considering the worldwide abundance of ultramafic rocks and the availability of coastal and open ocean environments. However, further research is required to understand the behavior of other elements and their impacts on ocean chemistry in EW processes before applying CO2 sequestration strategies.

DOI： 10.1007/s11631-024-00735-w

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Geological Journal  

Raman spectroscopy of carbonaceous materials (RSCM) was applied to 10 carbonaceous material (CM) -rich low- to medium-grade metasedimentary rock samples of Western Himalaya, Pakistan to assess their optimum thermal evolution. The RSCM thermometry is based on the degree of graphitisation of CM as a function of peak metamorphic temperature. Petrographic observations of the studied samples revealed two dominant CM morphologies. Type-I CM, represented by fine-grained discontinuous dust-like and scattered to thin sporadic layers, was more prevalent in low-grade metamorphic samples. Type-II CM, corresponding to continuous and extended thick fibres and elongated grain constellations, was dominant in medium- to high-grade metamorphic samples. The degree of crystallinity of CM and subsequent metamorphic temperatures were quantified by considering the intensity-based R1 and the area-based R2 ratio parameters. Low-grade samples from the Lesser Himalayan Sequence (LHS), having Type-I CM, resulted in RSCM peak temperatures between 306°C and 403°C. Medium- to high-grade samples from Higher Himalayan Crystalline (HHC), containing Type-II CM, yielded peak temperatures in the 482°C–560°C range. The extremely deformed sample from a fault zone in the LHS produced relatively higher temperature of 403°C, thereby suggesting heat associated with shearing due to fault activities resulting in CM recrystallisation and elevated temperature values. The study revealed that the peak metamorphic temperatures increase from south towards north following a progressive path of metamorphism in the region.

DOI： 10.1002/gj.5083

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：European Journal of Mineralogy  

Zircon grains preserve records of crystallization, growth, and/or deformation that can be envisaged from their internal structures and through the U–Pb isotope analysis. Electron backscatter diffraction (EBSD) is a non-destructive method for visualizing undeformed domains to differentiate them from those that are plastically deformed. In this study, we report EBSD analyses conducted on zircon grains, in thin sections with available textural information, from Himalayan eclogites. The studied eclogite samples show no petrographic evidence of shearing or mylonitization. However, several zircon grains preserve plastically deformed domains. These deformed domains display several degrees of misorientation relative to the undeformed domain and yielded geologically reset ages when analysed for U–Pb isotope ratios using nanoscale secondary ion mass spectrometry (NanoSIMS), in contrast to most undeformed domains which retained the protolith age. The degree of resetting is positively correlated with the extent of misorientation. These pieces of evidence indicate that plastic deformation in zircon grains, equilibrated at higher pressure–temperature conditions, affected the primary geochemical and geochronological records. Based on these observations, we assume that not only regional shearing/mylonitization in metamorphic rocks affects the geochemical records, but also that zircon grains in apparently unsheared high-grade metamorphic rocks behave plastically. The micro-scale intra-grain plastically deformed domains can easily be identified through EBSD analysis in the form of crystallographic misorientations. To extract meaningful geochronological results, it is necessary to identify undisturbed domains in zircon grains before applying any destructive analytical method.

DOI： 10.5194/ejm-35-1079-2023

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：International Journal of Sediment Research  

Arsenic (As) in natural hydrological systems is known as a worldwide major environmental concern. A geochemical and sedimentological study was done to ascertain the origin and geographical distribution of As in surface water and fluvial sediment collected from the floodplains/basins of the River Indus and its four major tributaries that drain through the northern Pakistan. The hydrogeochemical compositions of all five rivers were similar with calcium (Ca2+) and bicarbonate (HCO3−) being the dominating ions. The concentration of As ranged from 0.62–24.05 μg/L (average 3.7 ± 3.5 μg/L, n = 61) in river water, 2.3–23.4 mg/kg (average 5.7 ± 3.9 mg/kg) in suspended sediment, and 2.0–13 mg/kg (average 4.13 ± 2.3 mg/kg) in fluvial sediment. Various approaches were used, including mineralogical, sequential extraction, geochemical, and statistical analyses to investigate the distribution, behavior, and potential sources of As in the sediment. The effect of geological factors on the distribution of As was also studied. No noticeable changes in the relative abundance of minerals were observed in the sediment at different locations along the river. Both mineralogical and statistical analyses showed that silicate minerals like muscovite, biotite, and chloride are the main As reservoir while oxides minerals like hematite and magnetite, which are minor components in the sediment are second largest As carrier. A geochemical baseline, using the normalization and cumulative frequency distribution curves was constructed for As. The estimated mean human contribution of As was 3.4% in the Indus River, 1.9% in the Jhelum River, 13.7% in the Chenab River, 17.5% in the Ravi River and 5.4% in the Sutlej River, indicating relatively higher effects of anthropogenic activity along the Chenab River and Ravi River. The almost negligible effects of anthropogenic activities were additionally confirmed through the pollution assessment parameters estimated from the geo-enrichment, contamination factors, and accumulation index analyses. The current data suggest that As transported by the Indus River and its major tributaries is accumulated in the sediment and is potentially incorporated in the sedimentary aquifers situated along the Indus Basin and surrounding areas. Based on the current study, it is concluded that the source of As is dominantly geogenic whereas the role of anthropogenic activities is considered negligible except along the Ravi River which showed relatively a higher percentage (17.5%) of human or industrial contribution.

DOI： 10.1016/j.ijsrc.2023.04.001

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Journal of Structural Geology  

Electron backscattered diffraction (EBSD) and crystallographic preferred orientations (CPO) studies on Himalayan high- and ultrahigh-pressure eclogites are reported. Subduction-related peak eclogite facies (omphacite, garnet, quartz, rutile) and exhumation-related post-eclogite facies (hornblende, epidote, titanite) minerals were investigated to understand subduction and exhumation-related deformation regimes. Petrographic features from the studied eclogite samples show preferably shape-oriented omphacites coexisting with random to weakly shape-oriented garnets, and overgrown by hornblende and symplectites. Quartz grains are also randomly shape-oriented in the eclogite matrix whereas epidote grains display shape-preferred orientations. Based on EBSD data, an L-type CPO was dominant in omphacites in the studied eclogites, exhibited by the maximum density of [001] axes parallel to the lineation and the high density of poles to the (010) and (110) planes forming girdles perpendicular to the foliation. This CPO likely developed in a constrictional strain regime during the peak eclogite-facies conditions due to dislocation creep and is associated with an intra-crystalline (110) [001] and (110) <110> slip systems. EBSD data of garnets exhibit complex fabric, suggesting they most likely behaved like rigid objects in the presence of omphacite, indicating insignificant plastic deformation. EBSD data of quartz in high-pressure eclogites show irregular CPO but in ultrahigh-pressure eclogites the fabric is relatively strong. EBSD data of rutile show CPO of [001] axes strongly aligned along the lineation, suggesting its deformation was coeval to the omphacite. Titanite, mainly overgrown around rutile, indicates a random CPO different from rutile, suggesting its growth during late-stages. Hornblende in both types of eclogites shows identical fabric to that of omphacite, displaying CPO of [001] axes parallel to the lineation and poles of (010) and (110) planes form girdles perpendicular to the foliation, suggesting topotactic replacement over omphacite during exhumation. The EBSD data, combined with textural features, indicate syn-deformation peak metamorphism as well as preserve records of subsequent exhumation.

DOI： 10.1016/j.jsg.2023.104792

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Applied Geochemistry  

The Qilinchang (Pb–Zn)–Ag-Ge deposit of the Yangtze Platform, southwest China are hosted in the Early Carboniferous carbonate rocks of the Baizuo Formation. The deposit is located within the Sichuan-Yunnan-Guizhou (SYG) metallogenic province, which is western bounded by the Yangtze Platform in the southwestern part of China. Ore minerals are sphalerite, galena, pyrite, chalcopyrite, and marmatite, whereas gangue minerals are dolomite, calcite, and quartz. This study highlights the results of sphalerite chemistry analyzed by electron microprobe analyzer (EPMA), the laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and isotopic analysis. These techniques were used to investigate the major and trace concentrations in sphalerite from the Qilinchang deposit, in an attempt to provide noteworthy discernments into the ore-forming temperature and metal sources of the deposit. The calculated FeS (mole %) results obtained from Fe (wt. %) with the assumption that the sphalerite is stoichiometric in composition range from 0.02 to 13.48 mol % and mode at 3 mol %. This low FeS content falls within the bornite + pyrite + chalcopyrite field on the Fe–Zn–S system suggesting an increase in sulfur activity. The application of Ga/Ge ratios in sphalerite against the formation temperature was used to determine the homogenization temperature of this deposit. This expression is based on the existing Al/Si geothermometers as (Al/Si)total atomic ratio as a function of temperature calculated using available constants of hydrolysis reactions. The log10 (Ga/Ge) ratios calculated for this study range from −2.8 to 0.87, corresponding to formation temperatures of 100–227 °C, with an average of 180.3 °C. Likewise, correlation between PC1* and the homogenization temperature indicated that the calculated formation temperatures for this study ranged from 119.3 to 217.9 °C, which suggests that the deposit is sourced from a low-temperature environment. The δ34S of sphalerite is related to the thermochemical sulfate reduction (TSR) of Carboniferous seawater sulfate and are mainly derived from evaporites in the host strata producing H2S−rich fluid by TSR with restricted inducement from mantle-derived sulfur. The homogenous composition of Pb isotopic data of sphalerite indicates that the metals were predominantly originated from the basement rocks of the Mesoproterozoic-early Neoproterozoic rocks of the Kunyang Group. From these geochemical signatures, it can be inferred that the Qilinchang deposit was not linked to magmatic activities. It is proposed that the ore-forming fluids responsible for the formation of the deposit were generated from a low-temperature environment. Economic potential reveals the most important attributes of this deposit are high Zn and Pb grade (approximately 17.5% Zn and 6.6% Pb, 3.32 Mt of metal). Overall, the mineralization of the Qilinchang Pb–Zn deposit shows it a high-grade remarkable Pb–Zn deposit transiting between MVT and high-temperature carbonate-replacement Pb–Zn deposits. We suggest that the determination of the genetic type of this exceptional deposit is important to the research and exploration of similar Pb–Zn deposits in other metallogenic provinces of China.

DOI： 10.1016/j.apgeochem.2022.105545

Scopus

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1016/j.jsg.2023.104792

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Precambrian Research  

This study presents detailed petrography, bulk rock geochemistry, U-Pb dating, and Sr-Nd isotopes of pre-Himalayan granite gneisses and granites exposed in the Neelum Valley, NW Pakistan. To understand pre-Himalayan crustal growth history in the Indian plate, basement granitoids provide useful constraints. Two granites (the Jura and Neelum granites) and two granitic gneisses (the Nauseri and Jura gneisses) were investigated with the goal of their petrogenesis and constraining their geotectonic settings. Petrographically both granites and gneisses contain plagioclase, K-feldspar, quartz with S-type granite paragenesis of muscovite, garnet and tourmaline. Geochemically granites and gneisses are characterized by strongly peraluminous (A/NK > 1.1) character with a distinct mafic metapelitic sources. Notable negative Ta, Nb, and Ti compared to La and K, and a pronounced positive Pb anomalies in the studied rocks indicate convergence related source with a similar rare earth element pattern of upper continental crust. Two U-Pb zircon age populations, ca. 2429 ± 17 Ma and 1844 ± 11 Ma were obtained from the Nauseri gneiss whereas Jura gneiss yielded 865 ± 5.6 Ma. In contrast, Neelum and Jura granites yielded ages of 736 ± 11 Ma and 459.1 ± 3.5 Ma, respectively. Sr-Nd isotopic composition ((87Sr/86Sr)i = 0.7099 to 0.7303; εNd(t) = -8.1 to −3.6) together with the major and trace element geochemistry indicate that parental magmas of granites and gneisses were derived from the partial melting of upper continental crust during syn-collision tectonic settings. The Sr-Nd isotopes coupled with two-stage model ages further suggest incorporation of Archean and Paleoproterozoic reworked continental material that contained some mafic metapelitic component as well. Tectonically the parental magma of gneisses and granites could be linked with the global-scale orogenic events that operated during the assembly and rifting of the supercontinents of Columbia to Pangaea. Protoliths of Nauseri gneiss was possibly formed during the assemblage of Columbia supercontinent (1.8 Ga). Later, the Pan-African Orogeny provided additional pulse of magmatism that resulted Jura gneiss and Neelum granite. Moreover, the Bhimphedian orogeny in the Indian plate during Ordovician times generated the Jura granite of ca. 460 Ma.

DOI： 10.1016/j.precamres.2022.106920

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Minerals  

The Wadhrai granite stock is a part of the Nagar Parkar Igneous Complex, an extension of the Neoproterozoic Malani Igneous Suite of western Rajasthan. It is occupied by a petrographically uniform granite comprising perthite, plagioclase, quartz, with small quantities of biotite, opaque oxides, titanite, and secondary minerals. The rocks are sparingly porphyritic and contain dykes of microgranite, aplite, and rare pegmatite. In the south-central part, parallel sheets and swarms of mafic dykes, and in the western part very fine-grained felsic sheets intrude the body. The granite is metaluminous to peraluminous and characterized by high silica (73–76 wt%), and alkalis (7–9 wt%), and low CaO (0.15–1.4 wt%), MgO (0.15–0.38 wt%), Th (7–12 ppm), and U (1–2 ppm). On geochemical discriminant diagrams, it classifies mostly as A-type (with rather high Y/Nb (8.6 to 2.4, average 5.2) and low Nb/Ga and Ce (typical of A2-type), but sparingly as I-type. Chondrite-normalized patterns show enrichment in LREE over HREE, and small negative Eu anomalies, whereas mantle-normalized spidergrams display higher LILE over HFSE, distinct troughs for Nb, Sr, P, Ti, and spikes for La, Ce, Nd, Sm and Tb. The granite magma was possibly derived from a tonalite-granodiorite-dominated crustal source. Based on the above-mentioned geochemical evidence, it is interpreted that the source rocks of the magma of the Wadhrai granite likely developed initially in a continental margin subduction setting and underwent partial melting in a continental extensional environment.

DOI： 10.3390/min12101240

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：International Journal of Mining Science and Technology  

The Paleocene coals of the Salt Range in the Punjab Province of Pakistan have great economic potential; however, their trace element and stable isotopic characteristics have not been studied in detail except for a few sporadic samples. In this study, a total of 59 coal samples of which 14 are obtained from open cast mines have been investigated for elemental composition and δ13C-δ15N isotopic signatures. Average contents of trace elements such as Co, Cr, Cu, Pb, Sr, Th, U, V, and Zn are 7.4, 41.7, 11.2, 12.5, 90.2, 4.0, 1.9, 128, and 31.1 mg/kg, respectively. These values, when compared with the World Coal Clarke values, were relatively higher in low-rank coals in comparison with Clarke values for brown coals. Likewise, As (20.4 mg/kg), Co (6.6 mg/kg), Cr (22.4 mg/kg), Cu (13.3 mg/kg), Pb (19.2 mg/kg), Sr (154.7 mg/kg), Th (2.5 mg/kg), V (47.8 mg/kg), and Zn (75.1 mg/kg) were significantly higher in the sub-bituminous to bituminous coals of the Salt Range. Mineralogical analysis, based on X-ray diffraction and energy dispersive X-ray spectroscopy, revealed that the studied samples contain illite, kaolinite calcite, gypsum, pyrite, and quartz. Elemental affinity with organic and inorganic phases of coals calculated by an indirect statistical approach indicated a positive association of ash content with Ag, Al, Co, Cr, Cs, Cu, Mn, P, Rb, Pb, Th, U, and V, suggesting the presence of inorganic components in studied coals. However, As, Fe, Sr, and Zn exhibit negative correlations that imply their association with the organic fraction. The δ13C and δ15N isotopic range and average −24.94‰ to −25.86‰ (−25.41‰) and −2.77‰ to 3.22‰ (0.96‰), respectively, reflecting 3C type modern terrestrial vegetation were common in the palaeomires of studied coal seams. In addition, the trivial variations of 0.92‰ and 0.45‰ among 13C and 15N values can be attributed to water level fluctuations and plant assemblies.

DOI： 10.1016/j.ijmst.2022.03.007

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Geological Journal  

The Kohistan Arc preserves an exquisite and ideal petrogenetic record for studying mafic magmatism in an arc environment. Here we report the geochronological, mineralogical, and geochemical data of the gabbros from the Chilas Complex of Kohistan in order to understand their genesis, timing, role in crustal thickening, and tectonic evolution in Neo-Tethys. The mineral composition of orthopyroxene (Opx) in gabbros displays transitional to metamorphic behaviour with high amount of Al2O3 (0.59–2.66 wt.%), suggesting the influence of subsolidus re-equilibration during cooling or magmatic crystallization. Thermobarometric constraints propose the crystallization of Chilas gabbros around 892–985°C and ≤1.5 GPa pressure coupled with high H2O content (5.6%–7.7%). Geochemical modelling and isotopic peculiarities such as (87Sr/86Sr)i (0.000018–0.704140) and 206Pb/204Pb (18.526–18.554) suggest that the source of gabbros was depleted, likely controlled by peridotite melts and experienced insignificant crustal contamination. Relatively lower ratios of Nb/Yb (0.89–3.32) and TiO2/Yb (0.14–0.79) imply that the garnet was not a residual phase during the partial melting of a mantle source. The Chilas gabbros with depletion in Nb and Ta, enrichment in light rare earth element (LREE)s, the lower Ce/Pb ratios, plot of Th/La versus Th, and negative anomalies of Eu provide a consistent clue regarding the negligible participation of recycled components. Zircon U–Pb concordant ages of 83–86 Ma indicate the timing of emplacement and a Cretaceous magmatic event in the Chilas Complex. We infer that the Cretaceous magmatic flare-up is a significant crustal growth event of Kohistan and consider the underplating of mantle-derived magmas as one of the primary reasons for the crustal thickening based on zircon Hf isotopic signatures. The average chemical composition of Kohistan Complex provides support for the generation of andesitic magmas in arcs and the “andesite model” of continental crustal growth. We propose the similar petrogenesis for the Nidar, Kargil, and Chilas gabbros linking the formation of these variants within Neo-Tethys based on identical magmatic records.

DOI： 10.1002/gj.4665

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Lithos  

The Loe-Shilman carbonatite complex in northwest Pakistan comprises carbonatite and ultrapotassic silicate rocks. The age and environment of emplacement of these rocks have long been controversial, and therefore, impeded our understanding on the regional tectonic setting. New whole-rock geochemistry, Sr-Nd isotopic and zircon petrochronological data provide age and petrogenetic information on the carbonatite and ultrapotassic silicate rocks of the Loe-Shilman complex. Zircon U/Pb data yield 206Pb/238U weighted mean ages of 90.6 ± 1.0 Ma (n = 33) for the carbonatite and 89.3 ± 1.0 Ma (n = 30) for the ultrapotassic rocks, which indicates that the two lithologies were emplaced simultaneously during a single tectonic/thermal event. The Nd isotope data of the ultrapotassic rocks is homogenous (εNd(i) = −2.5 to −2.9) and overlap εNd(i) of the carbonatite (−2.6 to −2.8), indicating derivation from a common, enriched mantle source. Despite this temporal overlap, whole-rock geochemical data, however, indicates that generation of both rock types by fractional crystallization or liquid immiscibility is unlikely and that the carbonatite and ultrapotassic rocks are actually products of two independent melts generated by partial melting of an enriched sub-continental lithospheric mantle (SCLM) source at the same time. Trace element data further indicate that the ultrapotassic rocks are products of fractional crystallization of a melt produced by a low degree partial melting of an enriched mantle source, within the garnet stability field. Moreover, the ultrapotassic rocks and carbonatites show association with anorogenic and within-plate plume type tectonic settings, coeval with juxtaposition of the northwestern margin of the Indian plate over the Réunion hotspot mantle-plume during Late Cretaceous time.

DOI： 10.1016/j.lithos.2021.106497

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Lithos  

DOI： 10.1016/j.lithos.2021.106298

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：International Union of Geological Sciences  

Oxygen isotope data (δ18O) of quartz are reported for the San-yo and Ryoke belt granites, metamorphic rocks, and late-stage siliceous veins. The analyzed quartz showed δ18O values of 9.7-12.9‰ (relative to VSMOW) in granites, 15.1-17.3‰ in biotite schist, 16.4-17.8‰ in siliceous schist. The δ18O values of quartz in foliation-parallel and -normal veins are 16.6‰ and 17.3‰, respectively. The δ18O values of quartz in the granite samples are relatively higher than those crystallized from I-type granite magma (ca. 5–8‰) and similar with values of S-type granite magma (ca. 9–12‰). These features suggest partial melting of the chemically modified crust with sedimentary precursors to form the parental magma of granites. Hafnium isotope data of zircons from those granites, reported in an earlier publication, exhibited by εHf (t) values between +1.1 and -4.8, provide additional evidence for the formation of the granites from a continental crust with some incorporation of hydrothermally altered reworked crust before partial melting. The relatively higher δ18O values (> 15‰) of quartz in siliceous veins indicate their precipitation from silica- and 18O-rich fluids that were extracted from the slab-dehydration process during late-stages of their evolution.

DOI： 10.18814/epiiugs/2021/021012

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Arabian Journal of Geosciences  

The Mansehra Granitic Complex (MGC) is mainly comprised of Mansehra Granite, Hakale Granite, pegmatitic, microgranitic, and leucogranitic bodies in the northwest Lesser Himalaya of Pakistan. The Mansehra Granite is generally massive but occasionally gneissic due to local shearing manifested by solid-state deformation. Geochemical classification diagrams placed these plutonic rocks in calc-alkaline, peraluminous granite fields. The zircon saturation temperatures of the Mansehra Granite, Hakale Granite, and Leucogranite are 749–852, 709–779, and 749–754 °C, respectively. The temperature range (709–852 °C) of the MGC rocks is comparable with crystallization temperatures (670–817 °C) of the peraluminous S-type Lesser Himalayan Indian granites. Rb/Sr and Sr/Ba ratios suggest that the granitic melt of Mansehra Granite was derived through biotite dehydration-melting of the protolith Tanawal Formation at > 5 kbr pressure and > 700 °C temperature, whereas the Hakale Granite magma was generated at a relatively shallower depth and lower temperatures by muscovite fluid-absent anatexis of the source rock. The occurrence of andalusite in the contact aureole of Mansehra Granite, presence of perthitic microcline along with negative Nb, Sr, and Ti anomalies in spider diagram and higher Rb/Sr ratios reveal upper crustal signatures and low-pressure shallow emplacement (< 15 km) of the MGC magmatic bodies. The occurrence of psammitic restites, migmatites, and geochemical characteristics suggests the S-type trait of these plutonic rocks. The leucogranitic bodies most likely are the products of Na2O-rich residual melt and boron-rich fluids of the MGC magma. Harker’s variation diagrams indicate that the MG, HG, and LG display significant to poor relationships which suggest imperfect mixing of the non-homogenous protolith during partial crustal melting. However, scattering in some of the plots reflects the heterogeneity of the protolith and irregular distribution of minerals in the granitic melt of the MGC. Owing to affiliation with the continental-continental, syn-collisional geotectonic field, petrogenesis of the MGC rocks can be attributed to an Andean-type Cambro-Ordovician episode along the northern margin of east Gondwana.

DOI： 10.1007/s12517-021-07548-8

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Precambrian Research  

We investigated zircons from the Nagar Parkar Igneous Complex (NPIC) Gray and Pink granites for hafnium isotope and trace elements geochemistry to elucidate their petrogenetic source and tectonic setting. The studied zircons are characterized by oscillatory zoning, contain micro-inclusions of apatite, monazite, xenotime, and plagioclase. Rare-earth elements of the Neoproterozoic (ca. 750 Ma) zircons are characterized by a positive slope from La to Lu, exhibit distinct positive Ce- and negative Eu-anomalies that suggest their crystallization in magma that was fractionating plagioclase. The relatively smaller but variable Ce/Ce*N ratios (2–62), smaller Eu/Eu*N (0.01 to 0.45), and comparatively higher Th/U ratios (>0.30, reaching up to 3.20) affirm their derivation mainly from the continental crustal type magmas. The εHf(t) values of zircons in Gray and Pink granites range from +5.7 to +14.4 and +1.9 to +10.7, respectively, indicate their derivation from a juvenile crust and the absence of negative εHf(t) values point towards non-involvement of the older or reworked material during the crustal growth. The TDM model ages, calculated from the Hf isotope values of zircons, spread between 1119 and 736 Ma for Gray and 1013 and 900 Ma in Pink granites, further opine their derivation from a comparatively young and juvenile crust. Crystallization temperatures, estimated from the titanium content in zircon and zircon-saturation in whole-rock, range from 631 to 905 °C and 784 to 918 °C, respectively, show consistent results for the crystallization conditions of most granitic melts. Whole-rock major and trace element data, combined with zircon Hf isotope and trace elements geochemistry suggest within-plate A-type granitic magma that likely generated in a rift-related tectonic setting that persisted along the western margin of Rodinia during the Neoproterozoic era.

DOI： 10.1016/j.precamres.2020.106047

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Mineralogical Society of America  

<jats:title>Abstract</jats:title>
<jats:p>Thermometry of high-grade metamorphic rocks is difficult due to fast cationic diffusion during slow cooling, but the titanium content of calcium amphibole (Ti-Amp) can retrieve amphibole-forming temperature as high as ~1000 °C. Based on pseudosection modeling and past research survey, we find that Ti-Amp is controlled by temperature under the conditions of oxygen fugacity &lt;2 log units above the Ni-NiO oxygen buffer (ΔNNO+2), in subalkaline systems, and with the presence of Ti-phases (rutile, ilmenite, or titanite). We apply available experimental data to calibrate a new Ti-Amp thermometer for such conditions:</jats:p>
<jats:p>T ( C ° ) = 2400 1.52 − log ⁡ Ti Amp − 273</jats:p>
<jats:p>where T is temperature and log TiAmp is the Ti content of amphibole in atom per formula unit (apfu) expressed in the logarithm to base 10. The standard error of the calibration experiments is ±35 °C. This thermometer can be applied only if the aforementioned conditions are fulfilled. Besides, caution should be taken when applying the thermometer to rocks under subsolidus water-unsaturated conditions, which can be observed as non-equilibrium textures or low bulk-rock water content (&lt;1–1.5 wt%). The results of this thermometer may be underestimated if applied to rocks that are equilibrated above 850 °C and contain rutile and a significant amount of water (&gt;3.5–4 wt%).</jats:p>
<jats:p>The new thermometer can be successfully applied to amphibole-bearing natural igneous and meta-morphic rocks. In addition, we propose the Si vs. Ti in amphibole diagram that roughly demarcates the boundaries among the high amphibolite, high-temperature granulite, and ultrahigh-temperature granulite facies. Although pseudosection modeling provides details of the P-T evolution of studied rocks, the Ti-Amp thermometer is quick and easy to apply. However, further research is needed to improve our knowledge of the behavior and stability of amphibole and to improve the accuracy of both pseudosection modeling and conventional thermometry.</jats:p>

DOI： 10.2138/am-2020-7409

Scopus

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本地質学会  

<p>中央構造線・仏像構造線を挟んで太平洋側地域を西南日本外帯と呼び，この外帯においては様々な規模で花崗岩類が露出する.これらのほとんどは中期中新世のごく短い間に形成されたものであり，放射年代はc.a.10-15Maと報告されている.南九州地域に分布する花崗岩のほとんどが外帯花崗岩の一部であり，c.a.12~15MaのK-Ar年代及びフィッショントラック年代が報告されている（Miyachi，1985; 柴田，1978）．この中でも鹿児島県北西部の甑島列島は臼杵―八代構造線の延長上にあり，西南日本弧と琉球弧の会合部に位置するため日本海・沖縄トラフ拡大を考える上で重要な地域と言える．甑島列島は主に上甑島，中甑島および下甑島の3島からなる離島である．甑島列島には後期白亜紀の姫浦層群の堆積岩が広く分布しており、下甑島と一部上甑島に甑島には花崗岩が露出している(田代・野田，1973)．これらの花崗岩から分離した黒雲母KｰAr年代は13±4Ma（Miller et al., 1962）と報告されている．また，近年では琉球弧拡大との関連性についても議論が行われている（Ishihara et al., 1984; 新正・折橋，2019）．しかし甑島の花崗岩類の成因ついて詳細な研究はなされていない．したがって, 本稿では甑島花崗岩のレーザーアブレーション誘導結合プラズマ質量分析計(LA-ICP-MS)を用いたU-Pb放射年代測定およびその形成成因の推定を目的に研究を行ったことを報告する． 　調査地域の露頭において下甑島では比較的優白色で粗粒のの花崗閃緑岩，上甑島では灰白色から青白色細粒の花崗閃緑岩から閃緑岩が観察された．また，上甑島では白色花崗岩脈や石英脈もよく観察された．花崗岩と基盤岩の境界付近では接触熱変成作用によりホルンフェルスが形成されている．偏光顕微鏡下では，ほとんどの岩石は斜長石に富んだ角閃石黒雲母花崗閃緑岩であった．岩石内の主要構成鉱物は石英・斜長石・カリ長石・黒雲母・角閃石類，副成分鉱物はジルコン・アパタイト・イルミナイトが見られた．採取した岩石のうち下甑花崗閃緑岩帯南部と中部で2試料，上甑島花崗閃緑岩で1試料，これに接触するホルンフェルスより1試料からジルコンを抽出し,電子顕微鏡及びカソード像などで内部構造を把握した後、LA-ICP-MSによってU-Pb放射年代測定を行った.これにより下甑島の花崗岩南部（Kos-2）から10.38±0.50 Ma（MSWD＝0.94, n=14), 同じく，下甑島花崗岩中部（Kos-11）から11.17±0.53Ma(MSWD＝1.4,n=8),上甑島花崗閃緑岩（Kos-19）から10.03±0.44Ma(MSWD＝1.3,n=12),と周りのホルンフェルス（Kos-17）からは14-87Ma (n=5)の値が得られた. 甑島花崗岩は10Maと近辺に見られる西南日本外帯の紫尾山花崗閃緑岩 (c.a.13 Ma)，大隈花崗岩(c.a. 15 Ma)よりやや若い年代を示した．甑島花崗岩から分離したジルコンはオシラトリーゾーニングがよく見られ，中心部と周縁部で年代差はほとんどなかった．鹿児島地域の外帯花崗岩と全岩組成を比較したところ甑島花崗岩はややMeta-aluminousかつ苦鉄岩質なことから，玄武岩質マグマ成分を含む地殻の部分溶融から形成された花崗岩類だと考えられ，他の外帯花崗岩とは異なる火成活動に関連したものと推測される. したがって甑島花崗岩は他の外帯花崗岩と異なる火成活動によって形成されたことが示唆されたが，琉球弧背弧海盆との関連を議論するためにはより詳細な検討が必要である． </p><p></p><p><b>引用文献</b></p><p>Ishihara S., et al. (1984) Mining Geol., 34, 45-50. </p><p>Miller, J.A., et al (1962) Bull Geol. Surv. Japan, 13, 712-714.</p><p>Miyachi M.(1985) 岩石鉱物鉱床学会誌 80(9),406-409 </p><p>柴田賢 (1978) 地質調査所月報 29 (8), 551-554</p><p>新正 裕尚 他(2019) 第126年地質学会学術大会(2019 山口)要旨集 </p><p>田代正之，野田雅之（1972）地質学雑誌, 79巻7号, 465-480</p>

DOI： 10.14863/geosocabst.2021.0_065

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本地質学会  

<p>Oxygen isotope results (δ¹⁸O) of quartz are presented for the San-yo and Ryoke belt granites, associated metamorphic rocks (pelitic schists, siliceous schists), and two generations of siliceous veins (foliation-parallel and foliation-normal) that exist in pelitic and siliceous schists. Purified quartz grains from the above-mentioned lithologies were analyzed for δ¹⁸O using the conventional fluorination method. Quartz grains showed δ¹⁸O values (relative to VSMOW) of 9.7 to 12.9 ‰ in granites, 15.1 to 17.3 ‰ in biotite schist, and 16.4 to 17.8 ‰ in siliceous schist. The δ¹⁸O values of quartz from foliation-parallel veins in biotite schist were 16.6 ‰ whereas quartz grains from the foliation-normal veins in biotite schist had δ¹⁸O values of 17.3 ‰. The δ¹⁸O values of quartz in the investigated granite samples are comparatively higher than usually found in the typical I-type granites (ca. 5–8 ‰) and show some overlap with the S-type granites (ca. 9–12 ‰). These features suggest that the source magma of Ryoke and San-yo these granites was likely derived from the partial melting of the chemically modified crust with sedimentary precursors. Hafnium isotope data of zircons from the same granites, reported in an earlier publication (Mateen et al., 2019, Geosciences Journal 23, 917-931), exhibited by Ɛ_Hf (t) values between +1.1 and -4.8 provide additional evidence for the formation of the granites from a continental crust with some incorporation of the reworked older crustal material that was hydrothermally altered before partial melting. The relatively higher δ¹⁸O values (> 15 ‰) of quartz in foliation-parallel and foliation-normal veins indicate their precipitation from the silica- and ¹⁸O-rich fluids that were extracted from the slab-dehydration process during late-stages of their evolution.　Detailed results can be seen elsewhere (Rehman et al. 2021, Journal Episodes).</p><p></p><p>References</p><p>Mateen et al., 2019. Geosciences Journal 23, 917-931</p><p>Rehman et al. 2021. Episodes, https://doi.org/10.18814/epiiugs/2021/021012</p>

DOI： 10.14863/geosocabst.2021.0_064

担当区分：筆頭著者,　最終著者,　責任著者   掲載種別：研究論文（学術雑誌）  

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japan Association of Mineralogical Sciences  

<p>Zirconium in rutile thermometry data from the garnet granulites of the Jijal Complex of Kohistan arc, NW Himalaya are presented in this study. The garnet granulites are composed of garnet, clinopyroxene, plagioclase, quartz, symplectic augite/amphibole, rutile, ilmenite, zircon, and magnetite. Rutile grains range in size from 50 to 350 µm, occur as inclusion in garnet, clinopyroxene, and in plagioclase as well as along the grain boundaries. In total 19 rutile grains were analyzed for Zr contents using an X–ray Analytical Microscope (XGT–5000) by HORIBA. The Zr contents among the analyzed grains ranged between 450 and 920 ppm, where the analyzed spots with lower Zr contents (containing SiO₂ or Fe₂O₃), indicating some influence of host silicate or ilmenite, were removed from results. At the individual grain scale, most of the rutile grains exhibited homogeneous chemical compositions, regardless of their textural affinity. Temperature values, based on zirconium in rutile thermometry, ranged between 792 and 849 °C for rutile enclosed in garnet, 771 and 851 °C for rutile in clinopyroxene, and 784 and 862 °C for rutile in plagioclase whereas matrix rutile grains showed <i>T</i> values between 820 and 847 °C. Using the pressure–dependent zirconium in rutile thermometry, the <i>T</i> values were slightly lower (±50 to 100 °C). The maximum temperature values were consistent with the temperature data obtained from the conventional thermobarometry results (<i>P</i>; 1.2 ± 0.2 GPa and <i>T</i>; 818 ± 80 °C) whereas the lower values, likely, reflect chemical resetting of the analyzed grains during later stages of retrogression.</p>

DOI： 10.2465/jmps.191226

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本地質学会  

<p></p>

DOI： 10.14863/geosocabst.2019.0_118

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本地質学会  

【台風のためプログラム中止】　台風18号により学術大会の一部プログラムが中止となりました．中止となったプログラムの講演要旨については，著者のプライオリティ保護の見地から今回に限りJ-STAGEに公開し，引用可能とします．ただし，学術大会においては専門家による議論には供されていませんので「台風のためプログラム中止」との文言を付記します．（日本地質学会行事委員会）

DOI： 10.14863/geosocabst.2017.0_120

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本地質学会  

DOI： 10.14863/geosocabst.2016.0_141

担当区分：筆頭著者,　最終著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

DOI： 10.1111/iar.12097

担当区分：筆頭著者,　最終著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本地質学会  

DOI： 10.14863/geosocabst.2014.0_374

担当区分：筆頭著者,　最終著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本地質学会  

DOI： 10.14863/geosocabst.2014.0_413

担当区分：筆頭著者,　最終著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本地質学会  

DOI： 10.14863/geosocabst.2014.0_025

担当区分：筆頭著者,　最終著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

DOI： 10.1111/iar.12010

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人　日本鉱物科学会  

DOI： 10.2465/jmps.130118b

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

担当区分：筆頭著者,　最終著者,　責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本地質学会  

<jats:title>Abstract</jats:title><jats:p>The <jats:styled-content style="fixed-case">H</jats:styled-content>imalayan <jats:styled-content style="fixed-case">M</jats:styled-content>etamorphic <jats:styled-content style="fixed-case">B</jats:styled-content>elt of the <jats:styled-content style="fixed-case">K</jats:styled-content>aghan <jats:styled-content style="fixed-case">V</jats:styled-content>alley transect in northern <jats:styled-content style="fixed-case">P</jats:styled-content>akistan is a key area where rocks of the <jats:styled-content style="fixed-case">I</jats:styled-content>ndian <jats:styled-content style="fixed-case">P</jats:styled-content>late have been subducted to greater depths >100 km beneath the <jats:styled-content style="fixed-case">A</jats:styled-content>sian <jats:styled-content style="fixed-case">P</jats:styled-content>late and experienced high‐ to ultrahigh‐pressure metamorphism. At least three distinct metamorphic events can be recognized in the metamorphosed mafic rock units (eclogites and amphibolitized eclogites) of the <jats:styled-content style="fixed-case">K</jats:styled-content>aghan <jats:styled-content style="fixed-case">V</jats:styled-content>alley: (i) prograde; (ii) peak; and (iii) retrograde stages. Chemical composition, zoning pattern and inclusions in garnet, and metamorphic reactions among major mineral assemblage (garnet + clinopyroxene + quartz + amphibole + epidote) show that core portions of garnet grew under the prograde stage, whereas most of the middle portions were developed or recrystallized under the high‐pressure stage with <jats:styled-content style="fixed-case">P</jats:styled-content>–<jats:styled-content style="fixed-case">T</jats:styled-content> conditions at 2.3 ± 0.4 <jats:styled-content style="fixed-case">GP</jats:styled-content>a and 766 ± 107°<jats:styled-content style="fixed-case">C</jats:styled-content>. The rim portions of garnet in association with amphibole and presence of symplectites indicate amphibole‐eclogite to amphibolite‐facies (retrograde) stage with average <jats:styled-content style="fixed-case">P</jats:styled-content>–<jats:styled-content style="fixed-case">T</jats:styled-content> conditions at 1.5 ± 0.2 <jats:styled-content style="fixed-case">GP</jats:styled-content>a and 710 ± 75°<jats:styled-content style="fixed-case">C</jats:styled-content>. Zoning in garnet shows <jats:styled-content style="fixed-case">C</jats:styled-content>a‐poor wider cores, <jats:styled-content style="fixed-case">C</jats:styled-content>a‐rich thin middle portions, and chlorite and amphibole development along the outermost rims, suggesting prograde growth at cores and homogenous middle portions and retrogressive formation at rims during the amphibolite‐facies stage. These features suggest that most of the garnet grew during subduction of the <jats:styled-content style="fixed-case">I</jats:styled-content>ndian <jats:styled-content style="fixed-case">P</jats:styled-content>late lithosphere before the <jats:styled-content style="fixed-case">I</jats:styled-content>ndia–<jats:styled-content style="fixed-case">A</jats:styled-content>sia collision, whereas rim portions developed during rapid exhumation in the post‐collision stage.</jats:p>

DOI： 10.14863/geosocabst.2012.0_112

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本地質学会  

薩摩半島中央部の八瀬尾地域（四万十帯北帯）には蛇紋岩類が分布することが知られている．従来「貫入岩体」と見なされていた蛇紋岩類は，産状によって蛇紋岩体，蛇紋岩孤立岩塊および蛇紋岩主体の崩壊堆積物に区別できる．蛇紋岩体は，ほぼ水平もしくは浅い皿状の構造的境界面を介して西傾斜の砂岩層・砂岩泥岩互層（四万十累層群佐伯亜層群）の上に載っていて，岩体基底部の変形構造は上位側の東方への相対的変位を示唆する．これらの観察結果から蛇紋岩体は西側から移動してきて佐伯亜層群の上に定置したクリッペであると解釈できる．九州西南部の地体構造と蛇紋岩類の分布状況から推定すると，蛇紋岩クリッペの後背地は秩父帯の黒瀬川帯とされる領域にあると考えられる．

DOI： 10.5575/geosoc.117.468

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本地質学会  

DOI： 10.14863/geosocabst.2009.0.288.0

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：The Geological Society of Japan  

DOI： 10.14863/geosocabst.2008.0.49.0

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japan Association of Mineralogical Sciences  

Eclogites of the Kaghan valley, Pakistan Himalaya were investigated petrographically and geochemically. Based on petrography, geochemistry and mineral compositions, metamorphic history and a reasonable tectonic model are proposed. Eclogites exposed in the Kaghan valley are classified into two groups. Group I eclogites appear as massive and Group II are lens-type. Group I eclogites have a mineral assemblage of garnet, omphacitic clinopyroxene, quartz, symplectite with rare epidote and phengite. Accessory minerals include abundant zircon, rutile, ilmenite, and rare apatite. Group II eclogites have a mineral assemblage of garnet, omphacitic clinopyroxene, phengite, quartz/coesite, epidote, and symplectite. In accessory minerals rutile and ilmenite are common while zircon and apatite are rare. Different types of protolith are proposed for these eclogites. Group I eclogites have higher FeO and TiO₂ contents and trace element contents, and seem to be derived from gabbroic protolith. Group II eclogites have lower FeO and TiO₂ and trace element contents and were derived from basalts. Pressure-temperature-time path was constructed for the Kaghan valley eclogites using various mineral assemblages along with textural relationship and inclusions study. At least three distinct metamorphic stages were identified. The first stage is the prograde garnet growth stage deduced from the inclusion paragenesis in garnet core. The second stage records the ultrahigh-pressure metamorphic stage deduced from the presence of coesite inclusions in omphacitic clinopyroxene. The third stage is the decompression stage and is deduced from the quartz-albite-amphibole symplectite portions. These petrological and geochemical results combined with isotopic ages reported elsewhere indicate that basalts and associated gabbroic dikes were emplaced at about 267 Ma when the Indian plate was moving northward and passing above an unknown hot spot. The closure of the Tethys and initiation of collision of the Indian plate with the Kohistan-Ladakh Island Arc is reported from 65-50 Ma. After that the leading-edge of the Indian plate underwent eclogite facies metamorphism at 49 Ma and when it reached to depths of about 100 km, the ultrahigh-pressure metamorphic event took place at 46 Ma.

DOI： 10.2465/jmps.080222

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：一般社団法人 日本地質学会  

DOI： 10.14863/geosocabst.2007.0.273.0

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1016/j.lithos.2024.107535

その他リンク： https://doi.org/10.1016/j.lithos.2024.107535

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1016/j.jseaes.2024.106053

その他リンク： https://doi.org/10.1016/j.jseaes.2024.106053

担当区分：責任著者   記述言語：英語   掲載種別：研究論文（大学，研究機関等紀要）  

その他リンク： https://ir.kagoshima-u.ac.jp/records/2000141

担当区分：筆頭著者,　責任著者   記述言語：日本語   掲載種別：研究論文（大学，研究機関等紀要）   出版者・発行元：鹿児島大学  

その他リンク： https://ir.kagoshima-u.ac.jp/records/2000140

担当区分：最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.3389/feart.2023.1247797

記述言語：日本語   掲載種別：論文集(書籍)内論文  

記述言語：日本語   掲載種別：論文集(書籍)内論文  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1080/00206814.2021.1941324

担当区分：最終著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1016/j.lithos.2021.106496

DOI： https://doi.org/10.1016/j.lithos.2021.106496

担当区分：筆頭著者   記述言語：日本語  

担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（大学，研究機関等紀要）  

その他リンク： https://ir.kagoshima-u.ac.jp/?action=pages_view_main&active_action=repository_view_main_item_detail&item_id=15664&item_no=1&page_id=13&block_id=21

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier  

DOI： https://doi.org/10.1016/j.lithos.2020.105691

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： https://doi.org/10.1016/j.chemosphere.2020.126374

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MDPI  

DOI： https://doi.org/10.3390/min10060515

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier  

DOI： https://doi.org/10.1016/j.jog.2020.101723

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier  

DOI： https://doi.org/10.1016/j.lithos.2020.105430

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Japan Association of Mineralogical Sciences  

DOI： https://doi.org/10.2465/jmps.191226

記述言語：日本語   掲載種別：研究論文（大学，研究機関等紀要）   出版者・発行元：南方新社  

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer  

DOI： https://doi.org/10.1007/s12303-019-0003-1

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Kagoshima University  

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IUGS  

DOI： https://doi.org/10.18814/epiiugs/2019/019022

記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Kagoshima University  

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier  

DOI： https://doi.org/10.1016/j.lithos.2019.06.017

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SpringerLink  

DOI： https://doi.org/10.1007/s11356-019-06610-z

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

DOI： https://doi.org/10.1111/iar.12323

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier  

DOI： https://doi.org/10.1016/j.gexplo.2019.06.005

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SpringerLink  

DOI： https://doi.org/10.1007/978-3-030-01575-6_10

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

DOI： 10.1111/IAR.12323

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier  

DOI： https://doi.org/10.1016/j.gr.2018.04.018

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier  

DOI： https://doi.org/10.1016/j.gr.2017.12.004

その他リンク： https://www.sciencedirect.com/science/article/pii/S1342937X17303726

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

DOI： 10.1111/iar.12209

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SpringerLink  

DOI： https://doi.org/10.1007/s12517-017-3077-y

その他リンク： https://link.springer.com/article/10.1007/s12517-017-3077-y

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier  

DOI： 10.1016/j.precamres.2017.02.008

その他リンク： http://www.sciencedirect.com/science/article/pii/S0301926816304053

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（大学，研究機関等紀要）   出版者・発行元：KAGOSHIMA UNIVERSITY RESEARCH CENTER FOR THE PACIFIC ISLANDS  

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

その他リンク： https://www.schweizerbart.de/papers/ejm/detail/28/87355/EBSD_measured_crystal_preferred_orientation_of_eclogites_from_the_Sanbagawa_metamorphic_belt_central_Shikoku_SW_Japan

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier  

DOI： 10.1016/j.lithos.2016.06.001

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier  

DOI： 10.1016/j.jsg.2015.08.009

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（大学，研究機関等紀要）   出版者・発行元：Kagoshima University Research Center For The Pacific Islands  

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（その他学術会議資料等）   出版者・発行元：Wiley  

DOI： https://doi.org/10.1111/iar.12097

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（その他学術会議資料等）  

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Inteck, Rijeka, Croatia  

DOI： 10.5772/32859

担当区分：筆頭著者,　最終著者,　責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

DOI： 10.1111/j.1440-1738.2011.00774.x

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Springer  

DOI： https://doi.org/10.1007/978-3-642-12496-9_24

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

開催年月日： 2024年3月

記述言語：英語   会議種別：ポスター発表  

開催地：薩摩川内市、鹿児島県   国名：日本国  

開催年月日： 2024年3月

記述言語：英語   会議種別：ポスター発表  

開催地：薩摩川内市、鹿児島県   国名：日本国  

開催年月日： 2024年3月

記述言語：英語   会議種別：ポスター発表  

開催地：薩摩川内市、鹿児島県   国名：日本国  

開催年月日： 2024年3月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：薩摩川内市、鹿児島県   国名：日本国  

開催年月日： 2023年10月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Niigata University   国名：日本国  

開催年月日： 2023年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：京都大学   国名：日本国  

開催年月日： 2023年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：Osaka Metropolitan University   国名：日本国  

開催年月日： 2022年7月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Lyon   国名：フランス共和国  

開催年月日： 2022年6月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Baragali Campus, Peshawar Uni   国名：パキスタン・イスラム共和国  

開催年月日： 2022年6月

記述言語：英語   会議種別：口頭発表（招待・特別）  

開催地：Baragali Campus, Peshawar Uni   国名：パキスタン・イスラム共和国  

開催年月日： 2022年2月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：広島大学　(On-line)   国名：日本国  

開催年月日： 2021年9月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：on-line   国名：日本国  

その他リンク： https://confit.atlas.jp/guide/event/geosocjp128/subject/3ch301-12-10/advanced

開催年月日： 2021年9月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：On-line   国名：日本国  

その他リンク： https://confit.atlas.jp/guide/event/geosocjp128/subject/3ch301-12-09/advanced

開催年月日： 2021年5月

記述言語：日本語   会議種別：口頭発表（招待・特別）  

開催地：鹿児島   国名：日本国  

開催年月日： 2020年7月

記述言語：英語   会議種別：口頭発表（招待・特別）  

開催地：Islamabad (On-line)   国名：パキスタン・イスラム共和国  

開催年月日： 2019年11月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Kochi, Japan   国名：日本国  

その他リンク： https://www.researchgate.net/publication/337274038_Prolonged_continental_crustal_growth_of_the_Neoproterozoic_Nagar_Parkar_Igneous_Complex_the_western_extension_of_the_Malani_Igneous_Suite

開催年月日： 2019年5月

記述言語：英語   会議種別：口頭発表（招待・特別）  

開催地：Chiba, Japan   国名：日本国  

その他リンク： https://confit.atlas.jp/guide/event-img/jpgu2019/SMP29-P06/public/pdf?type=in&lang=en

開催年月日： 2015年5月

記述言語：英語  

開催地：千葉  

国際学会

開催年月日： 2015年5月

記述言語：英語  

開催地：千葉  

国際学会

開催年月日： 2014年9月

記述言語：日本語  

開催地：鹿児島  

国内学会

開催年月日： 2014年9月

記述言語：日本語  

開催地：鹿児島  

国内学会

開催年月日： 2014年9月

記述言語：日本語  

開催地：鹿児島  

国内学会

開催年月日： 2014年8月

記述言語：英語  

開催地：Baragali Summer Campus, University of Peshawar  

国際学会

開催年月日： 2014年4月

記述言語：英語  

開催地：横浜  

国際学会

開催年月日： 2013年9月

記述言語：英語  

開催地：Courmayeur, Italy  

国際学会

開催年月日： 2013年8月

記述言語：英語  

開催地：Tubingen, Germany  

国際学会

開催年月日： 2012年11月

記述言語：英語  

開催地：Charlotte, USA  

国際学会

開催年月日： 2012年9月

記述言語：日本語  

開催地：京都  

国内学会

開催年月日： 2012年9月

記述言語：日本語  

開催地：Osaka, Japan  

国内学会

開催年月日： 2012年8月

記述言語：英語  

開催地：Brisbane, Australia  

国際学会

開催年月日： 2012年6月

記述言語：英語  

開催地：Baragali Campus, University of Peshwar, Pakistan  

国際学会

開催年月日： 2012年5月

記述言語：英語  

開催地：Chiba, Japan  

国際学会

開催年月日： 2012年5月

記述言語：英語  

開催地：Chiba, Japan  

国際学会

開催年月日： 2012年2月

記述言語：英語  

開催地：Kurayoshi, Japan  

国際学会

開催年月日： 2012年2月

記述言語：日本語  

開催地：鹿児島  

国内学会

開催年月日： 2012年2月

記述言語：日本語  

開催地：鹿児島  

国内学会

開催年月日： 2011年8月

記述言語：英語  

開催地：Marianske Lazne, Czech Republic  

国際学会

開催年月日： 2011年5月

記述言語：日本語  

開催地：Chiba, Japan  

国内学会

開催年月日： 2011年5月

記述言語：英語  

開催地：Chiba, Japan  

国際学会

開催年月日： 2010年6月

記述言語：英語  

開催地：Taipei, Taiwan  

国際学会

開催年月日： 2010年5月

記述言語：英語  

開催地：Islamabad, Pakistan  

国際学会

開催年月日： 2010年5月

記述言語：日本語  

開催地：千葉、幕張メッセ  

国内学会

開催年月日： 2010年5月

記述言語：日本語  

開催地：千葉、幕張メッセ  

国内学会

開催年月日： 2010年5月

記述言語：日本語  

開催地：千葉、幕張メッセ  

国内学会

開催年月日： 2010年2月

記述言語：英語  

開催地：Varanasi, INDIA  

国際学会

開催年月日： 2009年5月

記述言語：日本語  

開催地：幕張メッセ国際会議場 (千葉)  

国内学会

開催年月日： 2008年12月

記述言語：英語  

開催地：San Francisco, USA  

国際学会

開催年月日： 2008年9月

記述言語：日本語  

開催地：秋田  

国内学会

開催年月日： 2008年3月

記述言語：英語  

開催地：Misasa, Tottori, Japan  

国際学会

開催年月日： 2007年10月

記述言語：英語  

開催地：Fukuoka, Japan  

国際学会

開催年月日： 2007年9月

記述言語：日本語  

開催地：Hokkaido, Japan  

国内学会

開催年月日： 2006年10月

記述言語：英語  

開催地：Philadelphia, Pennsylvania, USA  

国際学会

開催年月日： 2006年2月

記述言語：英語  

開催地：Misasa, Tottori, Japan  

国際学会

開催年月日： 2005年4月

記述言語：英語  

開催地：Osois, France  

国際学会

開催年月日： 2005年4月

記述言語：英語  

開催地：Osois, France  

国際学会

開催年月日： 2005年3月

記述言語：英語  

開催地：Misasa, Tottori, Japan  

国際学会

開催年月日： 2005年2月

記述言語：日本語  

開催地：Kagoshima, Japan  

国内学会

開催年月日： 2004年7月

記述言語：英語  

開催地：Niseko, Japan  

国際学会

開催年月日： 2004年7月

記述言語：英語  

開催地：Niseko, Japan  

国際学会

開催年月日： 2001年2月

記述言語：英語  

開催地：Tokyo, Japan  

国際学会

開催年月日： 2000年10月

記述言語：英語  

開催地：Lahore, Pakistan  

国際学会

記述言語：英語   会議種別：口頭発表（一般）  

開催地：Sultan Qaboos University, Al Khoudh, Muscat, Oman   国名：オマーン国