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1.
Permian Tectonic Evolution in Southwestern Khanka Massif: Evidence from Zircon U‐Pb Chronology,Hf isotope and Geochemistry of Gabbro and Diorite 总被引：8，自引：0，他引：8
Laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) zircon U-Pb dating and geochemical data for the Permian gabbros and diorites in the Hunchun area are presented to constrain the regional tectonic evolution in the study area. Zircons from gabbro and diorite are euhedral-subhedral in shape and display fine-scale oscillatory zoning as well as high Th/U ratios (0.26–1.22), implying their magmatic origin. The dating results indicate that the gabbro and diorite formed in the Early Permian (282±2 Ma) and in the Late Permian (255±3 Ma), respectively. In addition, the captured zircons with the weighted mean age of 279±4 Ma are also found in the diorite, consistent with the formation age of the gabbro within uncertainty. The gabbros belong chemically to low-K tholeiitic series, and are characterized by low rare earth element (REE) abundances, flat REE pattern, weak positive Eu anomalies (δEu), and depletion in high field strength elements (HFSEs, Nb, Ta, and Ti), similar to the high-aluminum basalts from island arc setting. Initial Hf isotopic ratios of zircons from the gabbro range from +7.63 to +14.6, suggesting that its primary magma could be mainly derived from partial melting of a depleted lithospheric mantle. The diorites belong to middle K calc-alkaline series. Compared with the gabbros, the diorites have higher REE abundance, weak negative Eu anomalies, and more depletion in HFSEs (Nb, Ta, and Ti), similar chemically to the volcanic rocks from an active continental margin setting. Initial Hf isotopic ratios and Hf two-stage model ages of zircons from the diorite range from +11.22 to +14.17 and from 424 to 692 Ma, respectively, suggesting that its primary magma could be mainly derived from partial melting of the Early Paleozoic and/or Neoproterozoic accretted lower crust. Taken together, it is suggested that geochemical variations from the Early Permian gabbros to the Late Permian diorites reveal that the subduction of the Paleo-Asian oceanic plate beneath the Khanka Massif and collision between the arc and continent (Khanka Massif) happened in the late stage of the Late Paleozoic. 相似文献
2.
V.B. Bazarova M.S. Lyashchevskaya T.R. Makarova R.A. Makarevich L.A. Orlova 《Russian Geology and Geophysics》2018,59(11):1410-1418
Overbank deposits in the Komissarovka River valley consist of alternating silt, clay silt, sand, and soils produced by lacustrine, alluvial, and aeolian deposition and by soil formation. Silt and sand layers in the lower part of the section correlate with the events of Early Holocene transgression and Middle Holocene regression of Lake Khanka. Deposition in the lowermost reaches of the Komissarovka River provides a faithful record of local Holocene landscapes controlled by level changes in Lake Khanka. 相似文献
3.
Abstract The Maizuru terrane, distributed in the Inner Zone of southwest Japan, is divided into three subzones (Northern, Central and Southern), each with distinct lithological associations. In clear contrast with the Southern zone consisting of the Yakuno ophiolite, the Northern zone is subdivided into the western and eastern bodies by a high-angle fault, recognized mainly by the presence of deformed granitic rocks and pelitic gneiss. This association suggests an affinity with a mature continental block; this is supported by the mode of occurrence, and petrological and isotopic data. Newly obtained sensitive high mass-resolution ion microprobe (SHRIMP) zircon U–Pb ages reveal the intrusion ages of 424 ± 16 and 405 ± 18 Ma (Siluro–Devonian) for the granites from the western body, and 249 ± 10 and 243 ± 19 Ma (Permo–Triassic) for the granodiorites from the eastern body. The granites in the western body also show inherited zircon ages of around 580 and 765 Ma. In addition, electron probe microanalysis (EPMA) monazite U–Th–total Pb dating gives around 475–460 Ma. The age of intrusion, inherited ages, mode of occurrence, and geological setting of the Siluro–Devonian granites of the Northern zone all show similarities with those of the Khanka Massif, southern Primoye, Russia, and the Hikami granitic rocks of the South Kitakami terrane, Northeast Japan. We propose that both the Siluro–Devonian and Permo–Triassic granitic rocks of the Northern zone are likely to have been juxtaposed through the Triassic–Late Jurassic dextral strike-slip movement, and to have originated from the Khanka Massif and the Hida terrane, respectively. This study strongly supports the importance of the strike-slip movement as a mechanism causing the structural rearrangement of the Paleozoic–Mesozoic terranes in the Japanese Islands, as well as in East Asia. 相似文献
4.
ABSTRACTThe tectonic affiliation of the Khanka Massif, in the easternmost section of the Central Asian Orogenic Belt (CAOB), is still a matter of debate. Here, we provide new constraints on the provenance and timing of deposition of Permian strata in the western margin of the Khanka Massif. The results, which include U–Pb dating of detrital zircon grains using laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS), provide evidence regarding the tectonic position of the Khanka Massif and its role in the late Palaeozoic evolution of the eastern CAOB. Detrital zircon grains from a sublitharenite (Pingyangzhen Formation), a litharenite (Liangzichuan Formation), and a metamorphic siltstone (Qinglongcun Group) yielded multiple age populations ranging from Neoproterozoic (~914 Ma) to Permian (~272 Ma). Combined with age constraints from overlying/late-stage igneous rocks and other magmatism of the Khanka Massif, we conclude that the dated strata were deposited during the early–middle Permian and were sourced from the Khanka Massif. A comparison between the detrital zircon age populations and the history of magmatic activity in the neighbouring areas suggests that the Khanka Massif was tectonically linked to the Songnen–Zhangguangcai Range Massif. Based on tectonic discrimination diagrams, we conclude that the western margin of the Khanka Massif was positioned in a convergent-boundary basin during the early–middle Permian. Strike-slip faulting along the Dunhua–Mishan Fault, in response to ridge subduction of the Paleo-Asian Ocean Plate, resulted in a north-eastward movement of the Khanka Massif. The occurrence of Precambrian detrital zircon grains (with ages of 1900–1700 and 900–700 Ma) implies the presence of an ancient basement within the Khanka Massif. 相似文献
5.
本文对出露在兴凯地块南部伊曼群的变沉积岩和侵入其中的火成岩进行了系统的锆石LA-ICP-MS U-Pb定年和Hf同位素研究,旨在查明伊曼群的形成时代与物源,并讨论侵入岩的成因和构造背景。伊曼群二云母片岩中锆石呈自形-半自形,显示典型的岩浆生长环带,暗示其岩浆成因。定年结果表明:100个碎屑锆石分析点给出了555～1322Ma的年龄区间,主要峰值年龄为555Ma、612Ma、700Ma、739Ma、769Ma、839Ma、936Ma;其中约533Ma的锆石ε_(Hf)(t)值介于-4.1～+3之间,二阶段模式年龄t_(DM2)介于1305～1755Ma之间;700～839Ma的锆石ε_(Hf)(t)值介于-3.7～+7.8之间,二阶段模式年龄t_(DM2)介于1246～1907Ma之间。侵入伊曼群的白云母二长花岗岩的定年结果显示为443±3Ma,此年龄对应ε_(Hf)(t)值介于-17.6～-4.2之间,二阶段模式年龄t_(DM2)介于1688～2529Ma之间。结合二云母片岩中碎屑锆石的最小年龄以及穿切其中花岗岩的形成时代,可以判定伊曼群二云母片岩的形成时代介于443～555Ma之间,应为新元古代晚期至晚奥陶世之间。基于伊曼群中碎屑锆石的年龄众数及与区域岩浆事件的对比,伊曼群的沉积物源主要来自松嫩地块和佳木斯地块的新元古代火成岩。此外,白云母二长花岗岩显示出埃达克岩的地球化学属性,岩浆源于加厚下地壳的部分熔融,暗示晚奥陶世研究区可能发生了陆壳加厚事件。 相似文献
6.
V. B. Bazarova L. M. Mokhova L. A. Orlova P. S. Belyanin 《Russian Journal of Pacific Geology》2008,2(3):272-276
New data on the evolution of Lake Khanka and the formation of onshore bars at its western coast in the late Holocene are discussed in the paper. The late Subatlantic age of the bars and climatic conditions of their formation have been established. In the middle Holocene (SA II), the climate was warm and Lake Khanka was in the transgressive phase. Its level was 0.8–1 m higher than at present. At the end of the Subatlantic period (SA III), when the climatic conditions were cooler, regression of the lake began and continues up to now. The spore-pollen samples of different genesis taken near the studied section were examined for the more reliable interpretation of paleoclimatic events. 相似文献
7.
兴凯湖花岗杂岩体的锆石U——Pb 年龄及其地质意义 总被引：3，自引：0，他引：3
佳木斯地块东南缘的兴凯湖花岗杂岩体主要由花岗闪长岩、二长花岗岩和正长花岗岩组成,其锆石的LA-ICP-MS U-Pb 测年结果显示,杨田寨南山岩体形成于257 ± 2 Ma,双子山岩体形成于215 ～212 Ma; 花岗岩的时空展布表明,两期花岗质岩浆的就位可能分别与古亚洲洋板块的俯冲作用和后造山伸展进程密切相关。结合本区和黑龙江东部其他花岗质岩石的年龄,揭示了佳木斯地块和兴凯地块在早古生代、二叠纪及三叠纪共同经历了三期大规模岩浆活动,暗示两者具有相同的构造属性,共同组成了同一陆块。 相似文献
8.
Fluorite Deposits at Voznesenka in the Khanka Massif, Russia: Geology and Age of Mineralization 总被引：1，自引：0，他引：1
Kohei Sato Kazuhiro Suzuki Munetomo Nedachi Shigeru Terashima Margarita D. Ryazantseva Anatoly A. Vrublevsky + Alexander I. Khanchuk ++ 《Resource Geology》2003,53(3):193-211
Abstract. A huge fluorite deposit at Voznesenka in the Khanka massif, Far East Russia is concluded to have formed at ca. 450 Ma in Late Ordovician time based on the K‐Ar ages for Li‐micas in the fluorite ore and greisenized leucogranite within the deposit. This conclusion is inconsistent with the current view of Devonian mineralization that stemmed from widely scattered whole‐rock Rb‐Sr isotope data for the heterogeneous leucogranite stocks influenced by strong alteration. The Voznesenka and neighboring fluorite deposits may have formed in Cambrian limestone in relation to the intrusion of the Li‐F‐rich felsic magma which has a similar chemistry to representative Li‐F‐rich felsic rocks including topaz granite and ongonite or topaz rhyolite; these rocks may be classified as a specific group of highly fractionated felsic magmas. Biotite granite plutons exposed in the Voznesenka district are divided in age into two groups based on the CHIME age data for zircon, monazite and xenotime: Ordovician and Permian. The Ordovician plutons seem to be coeval to the fluorite deposits and are characterized by F‐rich chemistry, reduced nature and association of tin mineralization with the deposition of fluorite and tourmaline. The biotite granite magmas of initially enhanced F contents could have been highly fractionated to form Li‐F‐rich leucogranite cupolas that provided fluorite deposits within the host limestone. Future prospecting for similar fluorite deposits is to be focused on areas of intersection between Ordovician Li‐F‐rich granite and Cambrian carbonate sequences. The Permian granite of southeastern margin of the Grodekovo batholith is characterized by lesser F content, oxidized nature and the lack of tin and fluorite mineralization in contrast to the Ordovician granite. The result of Permian age does not support the current view of Silurian age for the batholith and requires overall chronological reinvestigation in connection with the tectonic history of the Khanka massif because the Grodekovo is a representative of Paleozoic batholiths in Primorie. 相似文献
9.
对佳木斯—兴凯地块西南缘的黄松群进行其物源区特点、古风化条件和构造背景等分析结果显示,该套变质碎屑岩源岩为泥砂质沉积岩,源区母岩以中酸性火成岩为主。风化作用相关指数CIA、CIW及PIA,由杨木组到阎王殿组逐渐增高,而ICV值则呈递减趋势,体现了风化作用由弱到强,成分成熟度逐渐升高的特点。主量元素特征值SiO_2=69.95%、TiO_2=0.58%、TFe_2O_3+MgO=5.34%、Al_2O_3/SiO_2=0.21,微量元素特征值La=37.54×10~(-6)、Ce=72.83×10~(-6)、δEu=0.60、ΣREE=182.29×10~(-6)。REE配分模式与活动大陆边缘碎屑沉积物类似,并且在不同构造环境判别图解中,绝大多数样品投影点落入活动大陆边缘区。地球化学特征表明,黄松群碎屑岩可能沉积于活动大陆边缘环境。 相似文献
10.
兴凯湖翘嘴鲌(Culter albarnus)的生长特性 总被引：7，自引：0，他引：7
采用经典的VonBertalanffy生长方程和数理统计的方法 ,于 2 0 0 1— 2 0 0 2年在中俄界湖兴凯湖采集翘嘴 ,对其生长特性进行了研究。结果表明 ,翘嘴体长和体重的关系为W =0 .0 0 77L3.1 (r=0 .9881 ) ,VonBertalanffy生长方程为Lt=1 5 3.2 [1 -e- 0 .0 5(t+1 ) ];Wt=42 0 0 0 .3×[1 -e- 0 .0 6(t+1 ) ]3.1 ,体重生长拐点t=1 7.6龄 ,相应的体长为 95 .3cm ,体重为 1 2 70 6.6g。按生长指标值分析 ,阶段生长可划分为两个时期 ,即 1 7.6龄前的生长迅速期和 1 7.6龄后的生长减缓期。因此 ,为了保护翘嘴鱼类资源 ,天然渔业的捕捞个体规格应控制在 5 0 0 0g以上。 相似文献