{"created":"2021-03-01T06:09:48.709285+00:00","id":5933,"links":{},"metadata":{"_buckets":{"deposit":"2de0701c-19e2-459b-a13b-1bc541d2bcd2"},"_deposit":{"id":"5933","owners":[],"pid":{"revision_id":0,"type":"depid","value":"5933"},"status":"published"},"_oai":{"id":"oai:niigata-u.repo.nii.ac.jp:00005933","sets":["453:455","468:563:564"]},"item_6_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"沈み込み帯における炭質物の結晶構造進化に関する天然と反応速度論的実験に基づく研究"}]},"item_6_biblio_info_6":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2017-03-23","bibliographicIssueDateType":"Issued"},"bibliographic_titles":[{}]}]},"item_6_date_granted_51":{"attribute_name":"学位授与年月日","attribute_value_mlt":[{"subitem_dategranted":"2017-03-23"}]},"item_6_degree_grantor_49":{"attribute_name":"学位授与機関","attribute_value_mlt":[{"subitem_degreegrantor":[{"subitem_degreegrantor_name":"新潟大学"}]}]},"item_6_degree_name_48":{"attribute_name":"学位名","attribute_value_mlt":[{"subitem_degreename":"博士（理学）"}]},"item_6_description_4":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"Carbonaceous material (CM) is a widespread accessory phase in sediments, and its\\ncomposition and structure are sensitive to increasing peak metamorphic temperatures.\\nThe structural changes of CM as a function of temperature is widely applied as a\\ngeothermometry in very low- to medium-grade metamorphism. However, the\\nfundamental process involved in the conversion of amorphous carbon to graphite exhibits\\ncomplex devolatilization and recrystallization that depends not only on peak temperature,\\nbut also tectonic deformation, catalytic effects and fluid activity under a lithostatic\\npressure. Hence, it is key to understand the rate determining chemical reaction of CM to\\ngraphite through a combination of kinetic experiments and natural observations. In this\\nstudy, I have conducted detailed observations of natural CM in Shimanto accretionary\\n(SM) complex and Hidaka metamorphic belt (HMB), and carried out experimental kinetic\\nstudies based on X-ray diffraction (XRD), micro-Raman spectroscopy and Transmission\\nElectron Microscopic (TEM) observations.\\nThe natural structural evolution of CM extracted from metapelitic rocks in Hidaka\\nmetamorphic belt, Hokkaido, Japan, were initially investigated in detailed. The natural CM\\nshowed the heterogeneous recrystallization from 300 to 500 °C, suggesting the sigmoid\\ntransformation of amorphous, turbostratic and graphitic carbon. TEM observations\\nindicated that natural CM have undergone the microstructural evolution from randomly\\nmisoriented carbon sheets to highly oriented stacking with increasing temperature. To\\nfurther characterize the graphitization and carbonization process at lower temperature\\nregimes, I have investigated the natural structural evolution of CM in the Shimanto\\naccretionary complex, Kochi, Japan. The natural CM in mudstones systematically changed\\nits crystallinity toward the paleo out-of-sequence thrust, ranging between 180 and 280 °C.\\nThe devolatilization of CM represented by decrease in the aliphatic CH, aromatic CH and\\ncarboxyl peaks are well consistent with results of micro-Raman spectroscopy.","subitem_description_type":"Abstract"},{"subitem_description":"Based on the detailed field observations, I carried out high temperature high pressure (HPHT) experimental kinetic studies on graphitization using natural CMs in SM and HMB at various temperature of 1000 to 1450 °C for various durations (10 min to 115 hours) under a pressure of 1 GPa. Natural CMs extracted from sedimentary rocks\\ntransformed their morphology and crystallinity with increasing annealing temperatures and durations. The time-temperature relations of each crystal parameter by micro-Raman spectroscopy and XRD demonstrated sigmoidal transformations from an amorphous to a graphitic structure, suggesting the complex chemical reactions during graphitization. To assess these complex chemical processes, I adopted three different approaches for formulating the graphitization kinetics using a power rate model, a Johnson-Mehl-Avrami-Kolmogorov (JMAK) model and a superposition method. Irrespective of the models employed, the effective activation energies were estimated to lie between 259 and\\n339 kJ/mol, which are much lower than those reported previously for graphitization at 1\\natm. In addition to the isothermal experiments at 1 GPa, kinetic experiments at various pressure of 0.5 to 8 GPa at 1200 °C for 10 min to 24 hours were also conducted. The timepressure relations of each crystal parameter similarly demonstrated sigmoidal\\ntransformations from an amorphous to a graphitic structure, suggesting the pressureinduced\\nrecrystallization at constant temperature. In this study, we obtained the activation volumes of –22~–44 cm3/mol using a power rate model and a JMAK model during graphitization. Combining the effective activation energies and activation volumes, the structural evolution of CM based on experimental kinetic model can be expressed by\\nthree different factors of pressure P, metamorphic temperature T and duration t:\\nf(P, T, t) = C_min + (C_max – C_min) / {1+[((–22P +286686)/RT)/t]＾h},\\nwhere C_min and C_max are respectively the maximum and minimum values of each parameter, A the intercept of the Arrhenius plot, R the gas constant, and h is the reaction rate of the sigmoid function (named as the “Hill coefficient”). It is thus possible to calculate graphitization at any P-T-t relations in metamorphism. Utilizing the kinetic model, I tried to compare the experimental model based crystallinity of CM with natural\\nmetamorphic P-T-t conditions. In the case of Hidaka metamorphic belts, the natural CMs along the field P-T path of HMB proceeded structural evolution of CM from around 350 °C and form a graphite at around 450 °C. On the other hand, calculated structural evolution of CM started to recrystallize at around 400 °C, and form a graphite at over 500 °C for 10 million years. Although there still exist some factors for fully understanding the natural structural evolution of CM to a graphite, the experimental kinetic model can be applicable\\nto the thermal indicator in wide range of P-T conditions between 0.5 and 2 GPa at geologically reasonable temperatures (300~800 °C). The most important implication of our finding is that natural CM in the crust has proceeded fast recrystallization from an amorphous to a graphitic structure bearing upon temperature, pressure and duration of heaeting compared with the laboratory at 1 atm. Our data provide a new kinetic model\\nfor not only geothermometry but also geospeedmetry and geobarometry in subduction\\nzone.","subitem_description_type":"Abstract"},{"subitem_description":"炭質物は堆積岩中の普遍的な副成分鉱物であり，化学組成や結晶構造は最高変成温度の変化に依\\n存して敏感に変化する．この温度に依存した炭質物の結晶構造変化を利用することによって低変\\n成から中変成度での地質温度計として広く応用されている．しかしながら非晶質炭素からグラフ\\nァイトへの構造変化は変成温度だけではなく圧力・変形・触媒作用・流体が関与する複雑な脱ガ\\nス反応と再結晶化作用によって進行している．つまり反応速度実験と天然試料の観察を組み合わ\\nせるから炭質物の結晶構造進化に関する律速課程を理解することが重要である．本研究では\\nXRD・顕微ラマン分光分析・TEM による微細構造観察に基づく四万十帯・日高変成帯中の天然\\n炭質物の詳細な結晶構造の解析と天然試料を用いた反応速度実験を行った．\\nまず初めに北海道日高変成帯の泥質岩を研究対象に詳細な炭質物の結晶構造進化に関\\nする研究を行った．炭質物は約300℃から500℃にかけて非晶質構造から乱層構造をへてグラフ\\nァイト構造へ不均一な再結晶化を示す．結晶度に関連するパラメーターがシグモイド曲線を描く\\nことが特徴である．透過電子顕微鏡観察では，変成温度の増加につれて微細構造の組織も不規則\\nな乱層構造から高い配向性を示す積層構造への連続的な変化を観察できた．一方で高知県四万十\\n付加帯ではより低温での天然炭質物の結晶構造進化に関して詳細に研究をおこなった．泥質岩中\\nの炭質物は過去のプレート境界断層に向かって約180 ℃から280 ℃の温度幅で結晶度を変化さ\\nせた．顕微FTIR 分光を利用した分析では脂肪族CH, 芳香族CH やカルボキシル基の脱離に代\\n表される炭質物の熱分解反応が観察でき，顕微ラマン分光分析の結果とも整合的であった．\\nこれらの詳細な野外観察と分析に基づき，我々は四万十帯と日高変成帯中の炭質物を利\\n用した反応速度論に基づく高温高圧実験を1GPa, 1000~1450℃, 10 分から115 時間の条件にて\\n実行した．堆積岩中から抽出した天然炭質物は被熱時間と被熱温度が上昇するにつれて形態と結\\n晶度を変化させた．各パラメーターの温度―時間関係は，非晶質炭素からグラファイト構造へシ\\nグモイド曲線を示す．これは複雑な化学反応が石墨化の時に進行していることを示唆している．\\nそのような複雑な化学反応を評価するために，累乗則モデル・JMAK モデル・superposition 法を\\n利用したグラファイト化反応速度論の解析を試みた．","subitem_description_type":"Abstract"},{"subitem_description":"これらのモデルを使用すると， 約259 から339 kJ/mol の有効活性化エネルギーを見積もった．これは従来報告されてきた常圧下での石墨\\n化の活性化エネルギーよりも大幅に低い値である．1GPa 下での等温実験に加えて，1200℃にお\\nける0.5 GPa から8GPa まで10 分から24 時間の反応速度実験を行った．各結晶構造パラメータ\\nーの時間―圧力関係も同様に非晶質炭素からグラファイト構造へシグモイド曲線を示す．これは\\n一定温度にて炭質物が圧力に誘発されて再結晶化が進行していることを示唆する．本研究では累\\n乗則とJMAK モデルを利用して–22～–44 cm3/ mol の石墨化に対する活性化体積を得た．これら\\nの有効活性化エネルギーと活性化体積を利用すると炭質物の結晶構造進化は，三つの異なる要素\\nである圧力・変成温度・時間によって表現可能である:\\nf(P, T, t) = C_min + (C_max – C_min) / {1+[((-22P +286686)/RT)/t)＾h),\\nC_min と C_max は パラメーターの最大値と最小値. A はアレーニウスプロットの定数, R はガス定\\n数 (8.314 kJ.mol), で h はシグモイド関数の反応次数である (Hill 係数と呼ばれる). つまり変\\n成帯中の温度圧力時間を利用して炭質物の石墨化をモデル計算することが可能となる．このモデ\\nルを利用し，天然の温度圧力条件と実験に基づく結晶構造進化の比較を行った．日高変成帯の場\\n合，フィールドP-T path 上で天然の炭質物は約350℃から再結晶化が進行し450℃前後でグラフ\\nァイトを形成する．一方でモデル計算を行った炭質物の結晶構造進化では，1000 万年の被熱時間\\nにて約400℃から再結晶化が開始し，約500℃にてグラファイトを形成する. 我々の試算では天\\n然石墨化の完全な理解にはまだいくつかの欠陥が残っているが我々の実験に基づくカイネティ\\nクスモデルは熱指標として400℃から800℃, 0.5 から2 GPa における地質学的な温度圧力条件下にて適用可能である. 本研究における最も重要な点は，地殻中の天然炭質物は常圧の実験室に比べて非晶質炭素からグラファイト構造へ温度・圧力・速度に関連して早く再結晶化が進行することを発見したことである．我々の成果は今後沈み込み帯における地質温度計としてだけではなく，地質速度計・地質圧力計としての新しい反応速度モデルを提供するであろう．","subitem_description_type":"Abstract"}]},"item_6_description_5":{"attribute_name":"内容記述","attribute_value_mlt":[{"subitem_description":"学位の種類: 博士（理学）. 報告番号: 甲第4325号. 学位記番号: 新大院博（理）甲第424号. 学位授与年月日: 平成29年3月23日","subitem_description_type":"Other"}]},"item_6_description_53":{"attribute_name":"学位記番号","attribute_value_mlt":[{"subitem_description":"新大院博（理）甲第424号","subitem_description_type":"Other"}]},"item_6_dissertation_number_52":{"attribute_name":"学位授与番号","attribute_value_mlt":[{"subitem_dissertationnumber":"13101甲第4325号"}]},"item_6_full_name_3":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"51104","nameIdentifierScheme":"WEKO"}],"names":[{"name":"中村, 佳博"}]}]},"item_6_publisher_7":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"新潟大学"}]},"item_6_select_19":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_select_item":"ETD"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"Nakamura, Yoshihiro"}],"nameIdentifiers":[{"nameIdentifier":"51103","nameIdentifierScheme":"WEKO"}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2019-08-05"}],"displaytype":"detail","filename":"h28fsk424.pdf","filesize":[{"value":"27.8 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"本文","url":"https://niigata-u.repo.nii.ac.jp/record/5933/files/h28fsk424.pdf"},"version_id":"1e636915-50be-421e-aa4f-c6f3cc43a544"},{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2019-08-05"}],"displaytype":"detail","filename":"h28fsk424_a.pdf","filesize":[{"value":"185.4 kB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"要旨","url":"https://niigata-u.repo.nii.ac.jp/record/5933/files/h28fsk424_a.pdf"},"version_id":"eb5604e9-5265-4a32-80b3-4d3d80331777"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"thesis","resourceuri":"http://purl.org/coar/resource_type/c_46ec"}]},"item_title":"Natural and experimental kinetic studies on structural evolution of carbonaceous material in subduction zone","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Natural and experimental kinetic studies on structural evolution of carbonaceous material in subduction zone"},{"subitem_title":"Natural and experimental kinetic studies on structural evolution of carbonaceous material in subduction zone","subitem_title_language":"en"}]},"item_type_id":"6","owner":"1","path":["455","564"],"pubdate":{"attribute_name":"公開日","attribute_value":"2017-05-12"},"publish_date":"2017-05-12","publish_status":"0","recid":"5933","relation_version_is_last":true,"title":["Natural and experimental kinetic studies on structural evolution of carbonaceous material in subduction zone"],"weko_creator_id":"1","weko_shared_id":2},"updated":"2022-12-15T03:39:10.138032+00:00"}