|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Metamorphic P-T Path Differences between the Two UHP Terranes of Sulu Orogen, Eastern China: Petrologic Comparison between Eclogites from Donghai and Rongcheng显示文摘The Sulu Orogen constitutes the eastern part of the Sulu-Dabie Orogen formed by Triassic collision between the Sino-Korean and Yangtze plates. An HP Slice Ⅰ and two UHP slices Ⅱ and Ⅲ with contrasting subduction and exhumation histories within the Sulu Orogen were postulated. This study presents the metamorphic P-T paths of eclogites from the two UHP belts constructed by petrography, mineral chemistry and Perple_X P-T pseudosection modeling in the MnC(K)NFMASHO system. Eclogites from Slice Ⅲ mainly consist of omphacite, garnet and quartz, with minor rutile, ilmenite, amphibole and phengite. Eclogites from Slice Ⅱ show a porphyroblastic texture with epidote porphyroblasts and garnet, omphacite, phengite, quartz and rutile in matrix. Pseudosection modeling reveals that eclogites from Slice Ⅱ witness a peak metamorphism of eclogite-facies under conditions of 3.1–3.3 GPa and 660–690 ℃, and a retrograde cooling decompression process. The eclogites from Slice Ⅲ record a heating decompressive P-T path with a peak-P stage of 3.2 GPa and 840 ℃ and a peak-T stage of 2.4 GPa and 950 ℃, suggesting an apparent granulite-facies metamorphism overprint during exhumation. Both eclogites recorded clockwise P-T paths with peak P-T conditions suggesting a subduction beneath the Sino-Korean Plate to ~100–105 km depth. Combined with tectonic scenarios from previous studies, it is concluded that the two UHP crustal slices in the Sulu terrane have a similar geodynamic evolution, but the UHP rocks in Slice Ⅱ exhumed after the eclogitic peak-pressure conditions earlier than that of Slice Ⅲ. The existence of Slice Ⅱ diminished the buoyancy force on Slice Ⅲ, resulting in a granulite-facies overprint on Slice Ⅲ. The Sulu orogenic belt is made up of different crustal slices that underwent different subduction and exhumation histories, rather than a single unit. | Zhuoyang Li Yilong Li Jan R.Wijbrans Qijun Yang Hua-Ning Qiu Fraukje M.Brouwer | 2018 | Journal of Earth Science2018，29，5： | 6 |
| 2 | 柴北缘锡铁山花岗质片麻岩深熔作用年代和冷却历史:来自浅色体^(40)Ar/^(39)Ar年代学证据显示文摘长英质浅色体广泛出露于柴北缘造山带中段锡铁山地体花岗质片麻岩中,多呈脉状、不规则透镜状顺区域片麻理走向产出,主要由钾长石、斜长石、角闪石、石英以及少量黑云母组成,是黑云母花岗质片麻岩深融作用的产物。温压估算获得其形成条件为P=(6.5~9.6)′102 MPa,T=640~690℃,达麻粒岩相。选取浅色体角闪石和钾长石单矿物进行激光阶段加热^(40)Ar/^(39)Ar定年。角闪石共进行了17个阶段,其中3~17阶段数据形成平坦年龄谱,坪年龄为442.5±4.0 Ma;构成年龄坪的数据对应的等时线年龄为441.6±3.9 Ma,相应初始捕获氩比值为303±4,暗示该角闪石样品不含过剩^(40)Ar。坪年龄~442.5 Ma解释为角闪石初始结晶年龄,代表了锡铁山地区黑云母片麻岩发生深融(混合岩化)的时代。共生钾长石阶段加热获得一个低温和一个高温坪,坪年龄分别为307.5±2.9 Ma和323.3±3.0 Ma;等时线图谱暗示该钾长石样品未受过剩^(40)Ar干扰。坪年龄分别代表浅色体冷却到钾长石封闭温度~200℃和~250℃的时间。^(40)Ar/^(39)Ar定年结果显示锡铁山黑云母片麻岩深熔作用后经历了低速抬升(0.1~0.2 km/Ma)和缓慢冷却(3~3.6℃/Ma)的演化历史。 | 胡荣国 邱华宁 Jan R.WIJBRANS Fraukje M.BROUWER 何立言 王敏 | 2016 | 大地构造与成矿学2016，40，1： | 4 |
| 3 | Petrology and Metamorphic P-T Paths of Metamorphic Zones in the Huangyuan Group,Central Qilian Block,NW China显示文摘The Central Qilian Block is a Precambrian block in the Qilian Orogen,which has long drawn international attention for the study of orogeny and continental dynamics.The Huangyuan Group in the Datong area is one of the Precambrian metamorphic basement units in the Central Qilian Block and reflects metamorphism in the Barrovian garnet zone and sillimanite zone from south to north.Based on detailed fieldwork,this study presents a systematic study of petrography,mineral chemistry and phase equilibria of schists and gneisses from the two metamorphic zones.The garnet metamorphic zone is composed of micaschist,garnet-bearing micaschist and felsic leptynite,with interlayered plagioclase amphibolite.The sillimanite metamorphic zone consists of garnet-bearing biotite micaschist,sillimanite-bearing biotite-plagioclase gneiss and felsic leptynite.Garnet from the garnet metamorphic zone shows growth zoning with increasing almandine and pyrope and decreasing spessartine from core to rim.Garnet from the sillimanite metamorphic zone is almost homogeneous.Towards the outer rim,the contents of almandine and pyrope slightly decrease and grossular slightly increase.Biotite in both metamorphic zones is ferro-biotite.Plagioclase is oligoclase in garnet metamorphic zone and andesine in sillimanite metamorphic zone.Phase equilibrium modeling of a sample from garnet metamorphic zone resulted in a clockwise P-T path with a prograde stage(4.5–5.0 kbar,520–530℃),a peak P stage(9.8–10.2 kbar,560–570℃),a stage of thermal relaxation(8.0–8.5 kbar,580–590℃)and finally a retrograde stage(6.8–7.0 kbar,560–580℃).Thermodynamic modeling of a sample from the sillimanite metamorphic zone indicates a prograde stage(5.5–6.0 kbar,540–550℃)and a peak stage(7.8–8.5 kbar,660–690℃).The results indicate that the Huangyuan Group experienced medium-pressure amphibolite-facies metamorphism,which resulted from continental-continental collision between the Qaidam Block and the Central Qilian Block. | Zhuoyang Li Yilong Li Limin Zhao Jianping Zheng Fraukje M.Brouwer | 2019 | Journal of Earth Science2019，30，6： | 2 |
| 4 | Petrology of Garnet Amphibolites from the Hualong Group: Implications for Metamorphic Evolution of the Qilian Orogen, NW China显示文摘The Qilian Orogen marks the junction of the North China, South China and Tarim cratons. The mechanism of continental growth during the formation of the orogen remains unclear. Based on detailed fieldwork, we present a systematic study of petrography, mineral chemistry and phase equilibria of garnet amphibolites from the Hualong Group, which represents the Precambrian basement in the southern accretionary belt of the Qilian Orogen. The garnet amphibolites mainly consist of amphibole, plagioclase, garnet and quartz, with minor pyroxene, biotite and ilmenite. A peak stage of upper amphibolite facies to low-temperature granulite facies metamorphism and retrograde metamorphism in the amphibolite facies affected the samples. Garnet has a homogeneous composition of Alm66–71 Grs14–17 Prp9–12 Sps3–5, amphibole is ferro-hornblende, biotite belongs to the ferro-biotite species and pyroxene is dominated by orthopyroxene with few clinopyroxene. Pseudosection modeling of the garnet amphibolite samples indicates clockwise P-T paths. The samples witness peak metamorphism at conditions of ~4.9–6.3 kbar and ~755–820 ℃ in the upper amphibolite facies to lowtemperature granulite facies, and retrograde cooling and decompression at conditions of ~2.5–3.1 kbar and ~525–545 ℃. It is inferred that peak metamorphism with high temperature and low pressure occurred at ca. 450 Ma during northward subduction of the South Qilian oceanic crust beneath the central Qilian Block. When continental collision occurred between the central Qilian and the Qaidam blocks, the Hualong Block was accreted onto the South Qilian accretionary complex and experienced amphibolite facies retrograde metamorphism at ca. 440 Ma. | Yilong Li Limin Zhao Zhuoyang Li Biji Luo Jianping Zheng Fraukje M.Brouwer | 2018 | Journal of Earth Science2018，29，5： | 2 |
| 5 | Amphibolite facies retrograde metamorphism of the Zhujiachong eclogite, SE Dabieshan: 40Ar/39Ar age constraints from argon extraction using UV‐laser microprobe, in vacuo crushing and stepwise heating显示文摘 | H.‐N.QIU J. R.WIJBRANS F. M.BROUWER J.‐B.YUN L.‐H.ZHAO Y.‐G.XU | 2010 | Journal of Metamorphic Geology2010，，5： | 1 |
| 6 | Structural and tectonothermal evolution of the ultrahigh-temperature Bakhuis Granulite Belt,Guiana Shield,Surinam:Palaeoproterozoic to recent显示文摘We constrain the multistage tectonic evolution of the Palaeoproterozoic UHT metamorphic(P=0.9–1.0 GPa,T>1000℃,t=2088–2031 Ma)Bakhuis Granulite Belt(BGB)in Surinam on the Guiana Shield,using large-to small-scale structures,Al-in-hornblende thermobarometry and published fluid inclusion and zircon geochronological data.The BGB forms a narrow,NE–SW striking belt between two formerly connected,~E–W oriented granite-greenstone belts,formed between converging Amazonian and West African continental masses prior to collision and Transamazonian orogeny.Inherited detrital zircon in BGB metasediments conforms agewise to Birimian zircon of West Africa and suggests derivation from the subsequently subducted African passive margin.Ultrahigh-temperature metamorphism may have followed slab break-off and asthenospheric heat advection.Peak metamorphic structures result from layer-parallel shearing and folding,reflecting initial transtensional exhumation of the subducted African margin after slab break-off.A second HT event involves intrusion,at ca.0.49 GPa,of charnockites and metagabbros at 1993–1984 Ma and a layered anorthosite at 1980 Ma,after the BGB had already cooled to<400℃.The event is related to northward subduction under the greenstone belts,along a new active margin to their south.A pronounced syntaxial bend in the new margin points northward towards the BGB and is likely the result of indentation by an anticlinorial flexural bulge of the subducting plate.Tearing of the subducting oceanic plate along this bulge explains why the charnockites are restricted to the BGB.The BGB subsequently experienced doming under an extensional detachment exposed in its southwestern border zone.Exhumation was focused in the BGB as a result of the flexural bulge in the subducting plate and localised heating of the overriding plate by charnockite magmatism.The present,straight NE–SW long-side boundaries of the BGB are superimposed mylonite zones,overprinted by pseudotachylites,previously dated at ca.1200 Ma and 950 Ma,respectively.The 1200 Ma mylonites reflect transpressional popping-up of the BGB,caused by EW-directed intraplate principal compressive stresses from Grenvillian collision preserved under the eastern Andes.Further exhumation of the BGB involved the 950 Ma pseudotachylite decorated faulting,and Phanerozoic faulting along reactivated Meso-and Neoproterozoic lineaments. | Frank F.Beunk Emond W.F.de Roever Keewook Yi Fraukje M.Brouwer | 2021 | Geoscience Frontiers2021，12，2： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员