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| 1 | Field Relationships,Geochemistry,Zircon Ages and Evolution of a Late Archaean to Palaeoproterozoic Lower Crustal Section in the Hengshan Terrain of Northern China显示文摘The Hengshan complex forms part of the central zone of the North China Craton and consists predominantly of ductilely-deformed late Archaean to Palaeoproterozoic high-grade, partly migmatitic, granitoid orthogneisses, intruded by mafic dykes of gabbroic composition. Many highly strained rocks were previously misinterpreted as supracrustal sequences and represent mylonitized granitoids and sheared dykes. Our single zircon dating documents magmatic granitoid emplacement ages between 2.52 Ga and 2.48 Ga, with rare occurrences of 2.7 Ga gneisses, possibly reflecting an older basement. A few granitic gneisses have emplacement ages between 2.35 and 2.1 Ga and show the same structural features as the older rocks, indicating that the main deformation occurred after ~2.1 Ga. Intrusion of gabbroic dykes occurred at~1920 Ma, and all Hengshan rocks underwent granulite-facies metamorphism at 1.88-1.85 Ga, followed by retrogression, shearing and uplift.We interpret the Hengshan and adjacent Fuping granitoid gneisses as the lower, plutonic, part of a late Archaean to early Palaeoproterozoic Japan-type magmatic arc, with the upper, volcanic part represented by the nearby Wutai complex. Components of this arc may have evolved at a continental margin as indicated by the 2.7 Ga zircons. Major deformation and HP North China Craton collided to form the Trans-North China orogen. Shear zones in the Hengshan are interpreted as major lower crustal discontinuities post-dating the peak of HP metamorphism, and we suggest that they formed during orogenic collapse and uplift of the Hengshan complex in the late Palaeoproterozoic (<1.85 Ga). | A. KRONER S.A. WILDE P.J. O'BRIEN LI Jianghai C.W. PASSCHIER N.P. WALTE LIU Dunyi | 2005 | Acta Geologica Sinica(English Edition)2005，79，5： | 91 |
| 2 | Zircon SHRIMP U-Pb ages of the “Xinghuadukou Group” in Hanjiayuanzi and Xinlin areas and the “Zhalantun Group” in Inner Mongolia,Da Hinggan Mountains显示文摘A report is presented of SHRIMP zircon U-Pb dating data of meta-igneous and meta-sedimentary rocks of the Xinghuadukou Group(Xinlin-Hanjiayuanzi area,Heilongjiang Province)and meta-volcanic rocks of the Zhalantun Group(Zhalantun district,Inner Mongolia).The SHRIMP analyses show that the meta-igneous rocks from the Xinghuadukou Group formed at 506±10―547±46 Ma,belonging to Early-Middle Precambrian,whereas the meta-sedimentary rocks yielded detrital zircons,with ages of 1.0―1.2,1.6―1.8 and 2.5―2.6 Ga,indicative of deposition age at least<1.0 Ga. Meta-basic volcanic rocks from the Zhalantun Group have a formation age of 506±3 Ma.These data suggest that both the Xinghuadukou and Zhalantun Groups formed during Cambrian and/or Neoproterozoic time,rather than Paleoproterozoic time as previously thought.Early Precambrian inherited zircons in the meta-igneous rocks and numerous Precambrian detrital zircons in the meta-sedimentary rocks imply that these rocks were formed proximal to older crust.It is inferred that the Xinghuadukou and Zhalantun Groups represent Cambrian and/or Neoproterozoic vol- cano-sedimentary sequences formed in an active continental margin setting. | MIAO LaiCheng LIU DunYi ZHANG FuQin FAN WeiMing SHI YuRuo XIE HangQiang | 2007 | Chinese Science Bulletin2007，52，8： | 86 |
| 3 | Palaeoproterozoic Khondalite Belt in the western North China Craton: New evidence from SHRIMP dating and Hf isotope composition of zircons from metamorphic rocks in the Bayan Ul-Helan Mountains area显示文摘Zircom U-Pb age and Hf isotope analyses were made on gneissic granite and garnet-mica two-feldspar gneiss from the Helanshan Group in the Bayan Ul-Helan Mountains area, the western block of the North China Craton (NCC). Zircons from the gneissic granite commonly show core-mantle-rim structures, with magmatic core, metamorphic mantle and rim having ages of 2323±20 Ma, 1923±28 Ma and 1856±12 Ma, respectively. The core, mantle and rim show similar Hf isotope compositions, with single-stage depleted mantle model ages (TDM1) of 2455 to 2655 Ma (19 analyses). Most of the detrital zircons from the garnet-mica two-feldspar paragneiss have a concentrated U-Pb age distribution, with a weighted mean 207Pb/206Pb age of 1978±17 Ma. A few detrital zircons are older (2871 to 2469 Ma). The age for metamorphic overgrown rim was not determined because of strong Pb loss due to their high U content. The zircons show large variation in Hf isotope composition, with TDM1 ages of 1999 to 3047 Ma. In com- bination with previous studies, the main conclusions are as follows: (1) protolith of the khondalite se- ries in the Helanshan Group formed during Palaeoproterozoic rather than the Archaean as previously considered; (2) The results lend support to the contention that there is a huge Palaeoproterozoic Khondalite (metasedimentary) Belt between the Yinshan Mountains Block and the Ordos Block in the Western Block of NCC; (3) The widely-distributed bodies of early Palaeoproterozoic orthogneisses in the Khondalite Belt might be one of the important sources for detritus material in the khondalite series; (4) Collision between the Yinshan Block, the Ordos Block and the Eastern Block occurred in the same tectonothermal event of late Palaeoproterozoic, resulting in the final assembly of the NCC. | DONG ChunYan LIU DunYi LI JunJian WAN YuSheng ZHOU HongYing LI ChengDong YANG YueHeng XIE LieWen | 2007 | Chinese Science Bulletin2007，52，21： | 52 |
| 4 | SHRIMP U-Pb geochronology of the zircons from the Precambrian basement of the Qilian Block and its geological significances显示文摘Origin and tectonic evolution of the Qilian Precambrian basement on NW China were investigated using zircon U-Pb ages with collaborating stratigraphic and paleontological evidence. Zircon grains were separated from two schists, two granitic gneisses and one mylonized gneiss and dated with SHRIMP. Seventy percent of sixty-one detrital zircon ages from two schists ranges from 0.88 Ga to 3.09 Ga, mostly within 1.0 Ga to 1.8 Ga with a peak at 1.6 Ga to 1.8 Ga, and twenty percent varies from 2.0 Ga to 2.5 Ga. A few falls in the Archean and Neoproterozoic periods. The two granitic gneisses were dated 930±8 Ma and 918±14 Ma, whereas the mylonized granitic gneiss was dated 790±12 Ma. These ages represent two periods of magmatisms, which can be correlated with the early and late stages of magmatisms associated with the Jinningian movement on the Yangtze Blocks. The results from this and previous studies indicate that the ages of the Precambrian detrital zircons from the Qilian Block are widely distributed in the Proterozoic era, distinct from the North China Block which was stable in the Neo-Mesoproterozoic era. By contrast, the age histograms of the detrital zircons from the Qilian Block is similar to those from Precambrian basement of the Yangtze Craton. Therefore, it is suggested that the Qilian Block had a strong affinity toward the Yangtze Craton and might belong to the supercontinent Gondwana in the Neoproterozoic time. This inference is supported by Nd model age (TDM), stratigraphic, and paleontological evidence. It is further considered that the Qilian Block was rifted from the supercontinent Gondwana during late Sinian to form an isolated continent in the Proto-Tethyan Ocean, moving towards the Alaxa Block in the North China Craton. The part of Proto-Tethyan Ocean between the Qilian and Alaxa Blocks should correspond to the so-called Paleo-Qilian Ocean. Following the closure of the Paleo-Qilian Ocean in the early Paleozoic, the Qilian Block collided with the Alaxa Block to form the North Qilian Orogenic Belt. Based on this tectonic explanation, the North Qilian ophiolites should represent parts of lithosphere from the Proto-Tethyan Ocean. Lithological and geochronological evidence also indicates that the Qilian Block underwent continental reactivation possibly induced by the deep northward subduction of the North Qaidam Block in early Paleozoic time. | Kuoan TUNG Huai-Jen YANG Houng-Yi YANG LIU DunYi ZHANG JianXin WAN YuSheng Chien-Yuan TSENG | 2007 | Chinese Science Bulletin2007，52，19： | 42 |
| 5 | SHRIMP zircon U-Pb dating of late Paleoproterozoic kondalites in the Daqing Mountains area on the North China Craton显示文摘The Daqing Mountains area comprises a typical occurrence of the Khondalite Belt in the Western Block of the North China Craton (NCC). In this area, both early and late Paleoproterozoic metasedimentary rocks have been identified in what was originally called the Upper Wula Mountains 'Subgroup'. Six metasedimentary rock samples yielded SHRIMP U-Pb zircon ages of 2.56-2.04 Ga for detrital and 1.96-1.83 Ga for metamorphic zircons. Based on these data and previously published results, the following conclusions can be drawn: 1) The source region for the late Paleoproterozoic detrital sedimentary rocks is mainly 2.55 2.4 and 2.2 2.04 Ga in age, consistent with the early Precambrian geological history identified widely in the basement of the NCC. 2) The majority of sedimentary rocks of the khondalite series were deposited between 2.04 and 1.95 Ga, and then in a protracted period (1.96 and 1.83 Ga) underwent a complex history of amphibolite to granulite-facies metamorphism. | DONG ChunYan WAN YuSheng XU ZhongYuan LIU DunYi YANG ZhenSheng MA MingZhu XIE HangQiang | 2013 | Science China Earth Sciences2013，56，1： | 43 |
| 6 | Zircon SHRIMP U-Pb dating of meta-diorite from the basement of the Songliao Basin and its geological significance显示文摘The basement of the Songliao Basin mainly contains low-grade metamorphic rocks and granites. It has been long disputed whether the basin has Precambrian metamorphic basement. This is a report of zircon SHRIMP U-Pb dating results of a meta-diorite sample, which was taken from the Si-5 drilling hole in the southern portion of the Songliao Basin. The SHRIMP analyses indicate that the meta-diorite with a weighted mean 207Pb/206Pb age of 1839±7 Ma (2σ, n = 8) was emplaced during Paleo-Proterozoic time. Additionally, the meta-diorite has old Nd model ages (TDM1: 2999Ma; TDM2: 2849Ma). These data suggest that the south- ern part of the Songliao Basin do possess Precambrian base- ment. | WANG Ying ZHANG Fuqin ZHANG Dawei MIAO Laicheng LI Tiesheng XIE Hangqiang MENG Qingren LIU Dunyi | 2006 | Chinese Science Bulletin2006，51，15： | 35 |
| 7 | The Dongcaohe ophiolite from the North Qilian Moun-tains: A fossil oceanic crust of the Paleo-Qilian ocean显示文摘The Dongcaohe ophiolite, located at the south of the North Qilian subduction complexes, is a tectonic block with an exposed area of about 3 km×6 km. It consists of an intrusive section overlain by an ex- trusive section. The lower part of the intrusive section consists of cyclic layers of cumulate dunites, troctolites, anorthosites, anorthositic gabbros, and gabbros with small discordant dunite and troctolite bodies. This layered sequence grades upward to isotropic gabbros and gabbronorites, which are overlain by the extrusive sequence of diabasic sheeted dikes and basaltic lavas. The overall mineral crystallization sequence was olivine±Cr-spinel, plagioclase, clinopyroxene, orthopyroxene, and Fe-Ti oxides. The Cr-spinel (Mg#: 42-66, Cr#: 41-57) in these layered cumulates and present-day abyssal peridotites have similar compositions. Also, the compositional variations of the plagioclase and cli- nopyroxene in the intrusive section reflect crystallization from melts compositionally similar to the present-day ocean basalts. Moreover, the rare earth element (REE) and multi-element distribution pat- terns of the intrusive and extrusive lithologies in the Dongcaohe ophiolite are consistent with crystal- lization of mid-ocean ridge basalts. The zircon grains separated from the gabbronorite have an SHRIMP average 206Pb/238U weighted age of 497 ± 7 Ma, which is considered as the tectonic emplacement age of the Dongcaohe ophiolite. The field occurrence, mineral and whole-rock compositions indicate that the Dongcaohe ophiolite represents a well-persevered oceanic crustal fragment composed of a complete oceanic crustal section of layered cumulates at bottom upgrading through isotropic cumulates to sheeted dikes and lava flows. | Chien-Yuan TSENG Huai-Jen YANG Houng-Yi YANG LIU DunYi Ching-Lang TSAI WU HanQuan ZUO GuoChao | 2007 | Chinese Science Bulletin2007，52，17： | 38 |
| 8 | Archean Basement and a Paleoproterozoic Collision Orogen in the Huoqiu Area at the Southeastern Margin of North China Craton: Evidence from Sensitive High Resolution Ion Micro-Probe U-Pb Zircon Geochronology显示文摘这份报纸报导微探查的 U-Pb 锆石在 Huoqiu 区域为 Huoqiu 组和早前寒武纪的地下室的 granitoids 变老的敏感高分辨率离子,北方中国 Craton 的东南的边缘。Huoqiu 组在岩石协会和变态是类似的到 khondalite 系列,除了它包含 banded 铁形成的可观的数量。从 Huoqiu 的所有由岩屑形成的锆石组织元沉积的岩石是 3.0 Ga 和 2.75 Ga,没有任何 2.5 Ga 和更年轻的,作为通常在北方中国 Craton 的另外的区域在 Paleoproterozoic khondalite 系列被发现。在 Huoqiu 区域, 2.75 Ga 和 2.56 Ga granitoids 也被识别了。这个地下室集合在迟了的 Paleoproterozoic (1.84 Ga ) 期间经历了强壮的变态广泛地在北方中国 Craton 被开发的 tectonothermal 事件。因此, Huoqiu 组的形成时间能以由岩屑形成、变形的锆石年龄在 2.75 和 1.84 Ga 之间被抑制。它被考虑,与地区性的数据结合了,可以有 Paleoproterozoic 碰撞 orogen,在一个 NWWSEE 方向延长到北方中国 Craton 的南部的边缘。 | WAN Yusheng DONG Chunyan WANG Wei XIE Hangqiang LIU Dunyi | 2010 | Acta Geologica Sinica(English Edition)2010，84，1： | 35 |
| 9 | Detrital zircon age model of Ordovician Wenquan quartzite south of Lungmuco-Shuanghu Suture in the Qiangtang area, Tibet: Constraint on tectonic affinity and source regions显示文摘Early to Middle Ordovician strata, including Wenquan quartzite, occur widely in the Himalaya, Lhasa, and south Qiangtang blocks. The Wenquan quartzite occurs on the south side of the Lungmuco-Shuanghu Suture in the Qiangtang area, Tibet. A total of 145 analyses on detrital zircons from the quartzite show five age ranges of 520-700, ca. 800, 900-1100, 1800-1900, and 2400-2500 Ma, with particularly distinct age peaks of 625 and 950 Ma. The reliable youngest detrital zircon age is 525 Ma, and the oldest, 3180 Ma. Detrital zircons show large variations in Hf isotope composition, with depleted mantle model ages t DM (Hf) ranging from 750 to 3786 Ma. Based on data obtained in this study and by others, the main conclusions are as follows: 1) Low-grade metamorphic sedimentary rocks are distributed extensively in the south of the Lungmuco-Shuanghu Suture and are Phanerozoic in age; 2) Pan-African and Grenville-Jinning tectono-thermal events were well developed in the source region of the Wenquan quartzite; 3) the source region shows crustal addition and recycling of different periods; 4) Wenquan quartzite was derived from the Gondwana metamorphic basement, suggesting that the Qiangtang block is a Gondwanan fragment. | DONG ChunYan LI Cai WAN YuSheng WANG Wei WU YanWang XIE HangQiang LIU DunYi | 2011 | Science China Earth Sciences2011，54，7： | 39 |
| 10 | Formation ages and source regions of the Palaeoproterozoic Gaofan, Hutuo and Dongjiao groups in the Wutai and Dongjiao areas of the North China Craton from SHRIMP U-Pb dating of detrital zircons: Resolution of debates over their stratigraphic relationships显示文摘这份报纸在北方中国 Craton 的 Wutai 和 Dongjiao 区域报导 Gaofan, Hutuo 和 Dongjiao 组的元沉积的岩石的由岩屑形成的锆石年龄分布。由岩屑形成的锆石一从 Gaofan 组的 quartzite 主要是在年龄的 2.5 Ga,与大约 2.7 Ga 并且更旧。A 石英岩从 Hutuo 组的基础集团企业的卵石在到 Gaofan 组的 quartzite 的由岩屑形成的锆石年龄分发是类似的。为从 Dongjiao 组的 meta-feldspar-quartz 沙岩,由岩屑形成的锆石的年龄主要在 2.5 Ga 被集中。比 2.6 Ga 旧的锆石都没被识别,但是在年龄与一些是 1.84 Ga 和 2.22.0 Ga。与更早的研究结合了,下列结论能被得出:(1 ) Gaofan 组是在年龄的早 Palaeoproterozoic 并且对迟了的 Neoarchaean Wutai 花岗石绿岩岩层年轻得多、无关,它 unconformably 躺它。因此, Gaofan 组是在诺思中国 Craton 的最旧的 Palaeoproterozoic 元沉积的单位之一。(2 ) Hutuo 组在一个大陆人地下室上在中间的 Palaeoproterozoic (2.14-2.09 Ga ) 被扔,在早 Palaeoproterozoic Gaofan 组后面。(3 ) Dongjiao 组在 1.84 Ga 以后被形成,并且可能属于 Changcheng 系统的更低的部分。(4 ) 从所有三个组的由岩屑形成的锆石显示出 2.5 Ga 的一座明显的年龄山峰,从在北方中国 Craton 在太古代的结束在强烈 tectono-magma-thermal 事件形成的火的岩石被采购。 | WAN YuSheng MIAO PeiSheng LIU DunYi YANG ChongHui WANG Wei WANG HuiChu WANG ZheJiu DONG ChunYan DU LiLin ZHOU HongYing | 2010 | Chinese Science Bulletin2010，55，13： | 32 |
| 11 | SHRIMP Zircon U-Pb Dating of Gabbro and Granite from the Huashan Ophiolite,Qinling Orogenic Belt,China: Neoproterozoic Suture on the Northern Margin of the Yangtze Craton显示文摘摘要:最近识别的 Huashan ophiolitic m 藦?????? 尐?? | SHI Yuruo LIU Dunyi ZHANG Zongqing MIAO Laicheng ZHANG Fuqin XUE Hongmei | 2007 | Acta Geologica Sinica(English Edition)2007，81，2： | 29 |
| 12 | U-Th-Pb behavior of zircons under high-grade metamorphic conditions:A case study of zircon dating of meta-diorite near Qixia,eastern Shandong显示文摘This paper carried out a study on U—Th—Pb behavior of zircons in a'dry'rock system during high-grade metamorphism in the Archean basement of eastern Shandong.The studied sample has a mineral assemblage of plagioclase + K-feldspar + clinopyroxene + biotite + quartz and its protolith is considered to be diorite.The zircons are stubby,equant or irregular in shape and show fir-leaf, sectorial,banded or oscillatory zoning.They contain inclusions,including mineral assemblages of clinopyroxene + orthopyroxene + hornblende + quartz and plagioclase + K-feldspar + biotite + quartz. Fifty SHRIMP analyses were performed on 34 zircon grains,which commonly yielded high Th/U ratios (mostly>0.5).Most analyses are distributed along concordia from 2.54 to 2.25 Ga,with the youngest age being~1.95 Ga.Compositions and ages show large variations even in a same zircon grain.Combined with early studies,conclusions can be drawn as follows:1) the diorite underwent two episodes of high-grade metamorphism.at the end of the Neoarchean and the Paleoproterozoic(~2.50 Ga and~1.95 Ga or slightly later):2) high-grade metamorphism in a'dry'rock system may partially reset the U—Th—Pb system of zircons and.in this case,the ages between the oldest and youngest | Yusheng Wan Dunyi Liu Chunyan Dong Shoujie Liu Shijin Wang | 2011 | Geoscience Frontiers2011，2，2： | 27 |
| 13 | Finding of Neoproterozoic (~775 Ma) magmatism recorded in metamorphic complexes from the North Qilian orogen: Evidence from SHRIMP zircon U-Pb dating显示文摘标明日期的虾 U-Pb 从 Niuxinshan 片麻岩的花岗石和 Leigongshan 在锆石上被执行在北方 Qilian orogen 的片麻岩的吨子盐, NW 中国。结果分别地产出 776+-10 妈和 774 +-23 妈的加权的平均 ~(206 )Pb/~(238 ) U 年龄。Igneousmorphology,摆动的 zonings,和为这些锆石的相对高的 Th/U 比率建议 magmaticorigin。这些年龄作为岩浆炮兵阵地预定并且因此代表 aNeoproterozoic (约 775 妈) 被解释在北方 Qilian 区域的 magmatic 事件。thismagmatism 可能与超级大陆 Rodinia 的决裂有关,这被建议。这发现,和 750 ~ 800 妈的类似的年龄为南方中央的 Qilian 和北方 Qaidam 的附近的岩层报导了,具有到在韦斯特中国的 Rodinia 进化的理解的意义。 | Chien-Yuan Tseng Houng-Yi Yang WAN Yusheng LIU Dunyi Da-Jen Wen Tzung-Chi Lin Kuo-An Tung | 2006 | Chinese Science Bulletin2006，51，8： | 26 |
| 14 | SHRIMP U-Pb geochronology of the detrital zircons from the Longshoushan Group and its tectonic significance显示文摘Sixty-two geologically meaningful U-Pb dates were obtained by using SHRIMP technique for the detrital zircons in three metasedimentary rocks from stratigraphically uppermost parts of the Longshoushan Group in the present study. Eighty percents of these dates range from 1.7 Ga to 2.2 Ga with a peak at 1.8-2.0 Ga and twenty percents from 2.3 Ga to 2.7 Ga. The youngest detrital zircon is dated at 1724±19 Ma which is interpreted as the maximum depositional age of the metasedimentary rocks. Therefore, the age for the diagenesis and lithification of the original sedimentary rocks of the Longshoushan Group before the metamorphism must be younger than 1724±19 Ma. Comparison of the age histograms of these detrital zircons with the ages of the igneous rocks on the surrounding older massifs suggests that the sediments of the Longshoushan Group were most likely derived from the Alaxa Block and Tarim Craton. This implies that the affinity between Alaxa Block and Tarim Craton was strong and that they might have been a unified craton during middle-early Proterozoic time. | KuoAn TUNG HoungYi YANG LIU DunYi ZHANG JianXin ChienYuan TSENG WAN YuSheng | 2007 | Chinese Science Bulletin2007，52，10： | 24 |
| 15 | SHRIMP U-Pb zircon dating for lamprophyre from Liaodong Peninsula: Constraints on the initial time of Mesozoic lithosphere thinning beneath eastern China显示文摘It is undebated fact that the lithospheric mantle beneath eastern China was considerably thinned during the Mesozoic time. However, it has no adequate evidence for the exact timing when the lithosphere thinning started. The Liaodong Peninsula is located in the eastern segment of the North China Craton and is one of the important domains to explore the event of lithosphere thinning. SHRIMP U-Pb zircon dating and geochemical study were carried out for the lamprophyre dike swarm that intruded into the magnesite ore-beds in the Dashiqiao Formation of Paleoproterozoic Liaohe Group at the Huaziyu magnesite ore district, Liaodong Peninsula. The results indicate that these lampro- phyre dikes were intruded in late Jurassic (155±4 Ma) and show some geochemical characteristics of potassic magmas. It is now accepted that the lithosphere thinning took place in the late Mesozoic, and the peak thinning stage occurred in early Cretaceous (130―120 Ma). Considering the potassic mafic magmatism marking the onset of the lithospheric thin- ning, we therefore suggest that the studied late Jurassic potassic lamprophyre dike swarm could imply that the late Jurassic is the time that lithosphere thinning started. | JIANG Yaohui JIANG Shaoyong ZHAO Kuidong NI Pei LING Hongfei LIU Dunyi | 2005 | Chinese Science Bulletin2005，50，22： | 22 |
| 16 | Late Jurassic-Early Cretaceous Plutonism in the Northern Part of the Precambrian North China Craton:SHRIMP Zircon U-Pb Dating of Diorites and Granites from the Yunmengshan Geopark,Beijing显示文摘The Yunmengshan Geopark in northern Beijing is located within the Yanshan range.It contains the Yunmengshan batholith,which is dominated by two plutons:the Yunmengshan gneissic granite and the Shicheng gneissic diorite.Four samples of the Yunmengshan gneissic granite give SHRIMP zircon U-Pb ages from 145 to 141 Ma,whereas four samples of the Shicheng gneissic diorite have ages from 159 Ma to 151 Ma.Dikes that cut the Yunmengshan diorite record SHRIMP zircon UPb age of 162±2 and 156±4 Ma.The cumulative plots of zircons from the diorites show a peak age of 155 Ma,without inherited zircon cores,and the peak age of 142 Ma for granite is interpreted as the emplacement age of the Yunmengshan granitic pluton,whose igneous zircons contain inherited zircon cores.The data presented here show that there were two pulses of magmatism:early diorites,followed c13 Ma later by true granites,which incorporated material from an older continental crust. | SHI Yuruo ZHAO Xitao MA Yinsheng HU Daogong LIU Qisheng WU Zhenhan ZHAO Yuanyi LIU Dunyi | 2009 | Acta Geologica Sinica(English Edition)2009，83，2： | 17 |
| 17 | Formation age and tectonic environment of the Gantaohe Group,North China Craton:Geology,geochemistry,SHRIMP zircon geochronology and Hf-Nd isotopic systematics显示文摘The Gantaohe Group is an important early Precambrian unit in the Trans-North China Orogen,North China Craton,and is mainly composed of greenschist-facies metabasalt,meta-sandstone and dolomitic marble.We report whole-rock geochemical compositions and SHRIMP zircon ages as well as LA-ICP-MS Hf-in-zircon isotopeic analyses for metabasalts from the Gantaohe Group.SHRIMP dating yielded a weighted mean 207Pb/206Pb age of 2087±16 Ma(MSWD=1.3) for magmatic zircons,but there are also abundant ca.2.5 Ga inherited zircon xenocrysts.The magmatic zircons shows a large Hf(t) variation in Hf(t) from 7.17 to +0.45,suggesting an isotopically highly heterogeneous source for the metabasalt.Chemically all samples show no distinct Zr or Hf anomalies,and some samples show no Nd or Ta anomalies in a primitive mantle-normalized trace element variation diagram,and their whole-rock Nd(t) values range from 4.0 to 0.8.We suggest that the basalt is formed by partial melting of a depleted mantle source,followed by significant crustal contamination.Field observations,the presence of abundant inherited zircon,as well as isotope and trace elements geochemistry support formation of the Gantaohe Group on top of a continental basement.These data and the regional geology lead us to conclude that the Trans-North China Orogen constituted an intracontinental rift during the Paleoproterozoic that was connected to the Eastern Block since the end of the Archean. | XIE HangQiang LIU DunYi YIN XiaoYan ZHOU HongYing YANG ChongHui DU LiLin WAN YuSheng | 2012 | Chinese Science Bulletin2012，57，36： | 16 |
| 18 | SHRIMP U-Pb Dating of Zircons of a Dark Eclogite and a Garnet-bearing Gneissic Granitic Rock from Bixiling,Eastern Dabie Area,Anhui Province:Isotope Chronological Evidence of Neoproterozoic UHP Metamorphism显示文摘The paper reports SHRIMP U-Pb zircon data of a dark eclogite and a post-eclogite garnet-bearing gneissic granitic rock from the Bixiling area, Yuexi County, Anhui Province, in the eastern Dabie Mountains. The eclogite, which is metamorphosed basic tuff, contains very scarce zircons in omphacite or garnet, but more zircons in quartz. They usually exhibit a double-layered texture, as shown clearly in cathodoluminescence images. Their inner main parts give a 206Pb/238U age of 757±7 Ma, representing the approximate age of the high-pressure (HP)- ultrahigh-pressure (UHP) metamorphic event during which the eclogite was formed. The outer peripheral parts of the zircons, which have been modified by late-stage fluids, give an age of 223±3 Ma. The granitic rock contains more zircons of anatectic origin found mostly in feldspar and quartz and usually also showing a similar composite texture. The inner main parts of the anatectic zircons with oscillatory zoning give a 206Pb/238U age of 727±15 Ma for the | CHENG Yuqi LIU Dunyi I.S. WILLIAMS JIAN Ping ZHUANG Yuxun GAO Tianshan | 2000 | Acta Geologica Sinica(English Edition)2000，74，4： | 13 |
| 19 | SHRIMP zircon U-Pb dating of the Gangou granitoids,Central Tianshan Mountains,Northwest China and tectonic significances显示文摘Two types of granitoids,highly deformed augen granitoids and undeformed fine-grained granitoids,are widely distributed in Gangou area,Central Tianshan Mountains,Northwest China. The augen granitoids are high-K calc-alkaline characterized by high K2O,Rb,Y and Th,and low Sr and Sr/Y. They also have high contents of large ion lithophile elements (LILE),such as Ba,Rb,K and Th,and relatively low con-tents of high field strength elements (HFSE),such as Zr,Y and Nb. The fine-grained granitoids are calc-alkaline characterized by high Sr,low Y and HREE,similar to adakitic rocks,and with Na2O/K2O<2 (1.76―1.91),high ISr (0.70689―0.70981),and negative εNd(t ) (-2.4―-5.3). High-precision SHRIMP U-Pb zircon dating results indicate that the Gangou augen granitiods were formed at 428 ± 10 Ma,and the fine-grained granitoids were emplaced at 361―368 Ma. These geochemical and U-Pb zircon data have significant implications for the timing of closure of the Mishigou-Gangou Ocean and the evolution of the Central Tianshan orogenic belt. | SHI YuRuo LIU DunYi ZHANG Qi JIAN Ping ZHANG FuQin MIAO LaiCheng | 2007 | Chinese Science Bulletin2007，52，11： | 10 |
| 20 | Dating of zircon from high-grade rocks:Which is the most reliable method?显示文摘Magmatic zircon in high-grade metamorphic rocks is often characterized by complex textures as revealed by cathodoluminenscence(CL) that result from multiple episodes of recrystallization,overgrowth,Pb-loss and modifications through fluid-induced disturbances of the crystal structure and the original U-Th-Pb isotopic systematics.Many of these features can be recognized in 2-dimensionaI CL images,and isotopic analysis of such domains using a high resolution ion-microprobe with only shallow penetration of the zircon surface may be able to reconstruct much of the magmatic and complex postmagmatic history of such grains.In particular it is generally possible to find original magmatic domains yielding concordant ages.In contrast,destructive techniques such as LA-ICP-MS consume a large volume,leave a deep crater in the target grain,and often sample heterogeneous domains that are not visible and thus often yield discordant results which are difficult to interpret.We provide examples of complex magmatic zircon from a southern Indian granulite terrane where SHRIMP Ⅱ and LA-ICP-MS analyses are compared.The SHRIMP data are shown to be more precise and reliable,and we caution against the use of LA-ICP-MS in deciphering the chronology of complex zircons from high-grade terranes. | Alfred Krner Yusheng Wan Xiaoming Liu Dunyi Liu | 2014 | Geoscience Frontiers2014，5，4： | 9 |
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