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0, 1991). 3)區(qū)域變質(zhì)帶的控制因素和類型劃分)區(qū)域變質(zhì)帶的控制因素和類型劃分u與接觸變質(zhì)暈一樣,首先受區(qū)域變質(zhì)巖石性質(zhì)(成分結(jié)構(gòu)構(gòu)造特與接觸變質(zhì)暈一樣,首先受區(qū)域變質(zhì)巖石性質(zhì)(成分結(jié)構(gòu)構(gòu)造特征)控制征)控制u區(qū)域熱流值的變化(加熱)速率和變質(zhì)地質(zhì)體在地殼內(nèi)部埋藏區(qū)域熱流值的變化(加熱)速率和變質(zhì)地質(zhì)體在地殼內(nèi)部埋藏 折返速率有關(guān):低加熱速率折返速率有關(guān):低加熱速率 快速折返快速折返 ———— 單個變質(zhì)帶寬,反之單個變質(zhì)帶寬,反之亦然;亦然;u類型,按野外變質(zhì)梯度(類型,按野外變質(zhì)梯度( FMG)對應(yīng)的地?zé)崽荻戎捣郑海?yīng)的地?zé)崽荻戎捣郑? 高高 P/T型:型: 510 oC/km:藍(lán)閃石:藍(lán)閃石 硬柱石、藍(lán)晶石硬柱石、藍(lán)晶石 硬玉、柯石英硬玉、柯石英 金剛石;金剛石;? 中中 P/T型型 :: 1040 oC/km:藍(lán)晶石:藍(lán)晶石 矽線石;矽線石;? 低低 P/T型:型: 4080 oC/km:紅柱石:紅柱石 矽線石;矽線石; 從高從高 P/T型到低型到低 P/T型前進(jìn)變質(zhì)帶,其單個變質(zhì)帶的寬度由寬變窄型前進(jìn)變質(zhì)帶,其單個變質(zhì)帶的寬度由寬變窄,有人將相應(yīng)的變質(zhì)作用稱高、中、或,有人將相應(yīng)的變質(zhì)作用稱高、中、或 P/T型區(qū)域變質(zhì)作用型區(qū)域變質(zhì)作用4)) Paired Metamorphic Belts of JapanThe Sanbagawa (三波川 ) and Ryoke (領(lǐng)家 ) metamorphic belts of Japan. From Turner (1981) Metamorphic Petrology: Mineralogical, Field, and Tectonic Aspects. McGrawHill and Miyashiro (1994) Metamorphic Petrology. Oxford University Press. 島弧洋中脊 Backarc basin4)) Paired Metamorphic Belts of Japan? This figure suggests that the 600oC isotherm, for example, could be as deep as 100 km in the trenchsubduction zone area, and as shallow as 20 km beneath the volcanic arcMiyashiro (1961, 1973) suggested that the occurrence of coeval metamorphic belts, an outer, highP/T belt, and an inner, lowerP/T belt ought to be a mon occurrence in a number of subduction zones, either modern or ancientFigure 2113. Some of the paired metamorphic belts in the circumPacific region. From Miyashiro (1994) Metamorphic Petrology. Oxford University Press