The discovery of the amphibolite in the Kalamaili ophiolitic mélange formed in mid-oceanic ridge setting
-
摘要:
在新疆东准噶尔卡拉麦里蛇绿混杂带中新发现了斜长角闪岩，主要呈透镜状夹持于变质橄榄岩之中。采用LA-ICP-MS锆石U-Pb定年方法，获得斜长角闪岩锆石U-Pb年龄为（402.7±4.9）Ma，表明其原岩形成时代为早泥盆世。岩相学、岩石地球化学及Sr-Nd同位素分析表明，斜长角闪岩的原岩可能为变辉长岩，样品SiO2含量为47.58%~50.57%，MgO含量为8.04%~9.12%及对应的Mg#值为63.89~67.64，Ni和Cr含量分别为68.9×10-6~99.2×10-6和306×10-6~398×10-6，与洋中脊拉斑玄武岩一致。稀土元素配分曲线呈弱亏损型至平坦型，微量元素蛛网图总体与N-MORB相似，无明显的Nb、Ta Zr、Hf及Ti的亏损，各元素的丰度也与N-MORB接近。样品均具有较高εNd（t）值（8.7~9.2），表明其原始岩浆来源于亏损地幔。在TiO2-FeOT/MgO和Th-Ta-Hf/3构造环境判别图解中，所有样品均落入洋中脊玄武岩区域内。结合区域地质构造背景，认为斜长角闪岩可能形成于洋中脊构造环境，代表了被肢解的古洋盆岩石圈残片，应为卡拉麦里蛇绿混杂岩的组成部分，揭示了该洋盆的开启时限至少可追溯至早泥盆世。
Abstract:The amphibolite, which is lenticular in shape and is wrapped in metamorphic peridotites, was discovered in the Kalamaili ophiolitic mélange belt, East Junggar, Xinjiang. LA-ICP-MS zircon U-Pb dating of the amphibolite yielded an age of (402.7±4.9) Ma, indicating that it was formed in Early Devonian. Petrographic, whole-rock chemical and Sr-Nd isotopic data suggest that the source rocks of the amphibolites were probably the meta-gabbro. The rock samples have SiO2, MgO and Mg# values of 47.58%-50.57%, 8.04%-9.12% and 63.89-67.64, respectively. They also have Ni and Cr values of 68.9×10-6-99.2×10-6 and 306×10-6-398×10-6. All these geochemical data are similar to the average value of MORB. The REE of the rocks show weak depletion to flattening pattern. The features of the trace elements of the rocks are similar to those of the N-MORB, suggesting no obvious depletion of Nb, Ta, Zr, Hf and Ti. The samples have high εNd (t) values varying from 8.7 to 9.2, suggesting that the original magma of the rocks was derived from the depleted mantle. On the TiO2 versus FeOT/MgO and Th versus Ta versus Hf/3 diagrams, all samples fall in the MORB field. Combined with the geological background, the authors hold that the amphibolite was probably formed in a midoceanic ridge setting and represented the lithosphere fragments of the dismembered ancient ocean basin, being a part of the Kalamaili ophiolitic mélange. This research reveals that the opening time of the Kalamaili ocean basin was the Early Devonian at least.
-
Key words:
- Kalamaili ophiolitic mélange /
- amphibolite /
- Sr-Nd isotope /
- MORB /
- East Junggar
-
-
图 6 斜长角闪岩Zr/TiO2×0.0001-SiO2岩石分类图解(a，据Winchester and Floyd, 1977)和AFM图解(b，据Irvine and Baragar, 1971)
Figure 6.
图 7 斜长角闪岩MgO-CaO-FeOt图解(a) (据Masra, 1971)和MnO-TiO2图解(b) (据赵振华, 1997)
Figure 7.
图 9 斜长角闪岩源区判别图解（据Shervais, 1982）
Figure 9.
表 1 斜长角闪岩（KLA01）LA-ICP-MS锆石U-Pb同位素定年结果
Table 1. LA-ICP-MS zircon U-Pb isotopic analyses of the amphibolites (KLA01) in the Kalamaili ophiolitic mélange
下载: 导出CSV
表 2 斜长角闪岩主量元素(%)、微量元素(10−6)及Sr-Nd同位素分析结果
Table 2. Major elements (%), trace elements (10−6) and Sr-Nd isotopic compositions of the amphibolites in the Kalamaili ophiolitic mélange
下载: 导出CSV
-
Andersen T. 2002. Correction of common Pb in U-Pb analyses that do not report 204Pb[J]. Chemical Geology, 192:59-79. doi: 10.1016/S0009-2541(02)00195-X
Chen B, Jahn B M. 2004. Genesis of post-collisional granitoids and basement nature of the Junggar Terrane, NW China:Nd-Sr isotope and trace element evidence[J]. Journal of Asian Earth Sciences, 23:691-703. doi: 10.1016/S1367-9120(03)00118-4
DePaolo D J. 1981. Trace element and isotopic effects of combined wall rock assimilation and fractional crystallization[J]. Earth Planetary Science Letters, 53:189-202. doi: 10.1016/0012-821X(81)90153-9
Fang Aimin, Wang Shigang, Zhang Junmin, Zang Mei, Fang Jiahu, Hu Jianming. 2015. The U-Pb ages of zircons from the gabbro in the Klamaili ophiolite, North Xinjiang and its tectonic significances[J]. Chinese Journal of Geology, 50(1):140-154 (in Chinese with English abstract). https://www.researchgate.net/publication/281799299_The_U-Pb_ages_of_zircons_from_the_gabbro_in_the_Kalamaili_ophiolite_North_Xinjiang_and_its_tectonic_significances
Frey F A, Green D H, Roy S D. 1978. Integrated models of basalt petrogenesis:A study of quarti tholeiites to olivine melilities from south eastern Australia utilizing geochemical and experimental petrological data[J]. Journal of Petrology, 19:463-513. doi: 10.1093/petrology/19.3.463
He Gguoqi, Li Maosong, Jia Jindou, Zhou Hui. 2001. A discussion on age and tectonic significance of ophiolite in Eastern Junggar, Xinjiang[J]. Acta Scientiarum Naturalium Universitatis Pekinensis, 45(5):819-824 (in Chinese with English abstract). https://www.researchgate.net/publication/282736819_A_discussion_on_age_and_tectonic_significance_of_ophiolite_in_Eastern_Junggar_Xinjiang
Hu Chaobin, Liao Qunan, Fan Guangming, Chen Shuai, Wu Weiwei, Tian Jian, Wang Fuming. 2014. Discovery of MOR-type ophiolites from the Dishuiquan region, eastern Junggar[J]. Chinese Science Bulletin, 59:2213-2222 (in Chinese with English abstract). doi: 10.1360/N972013-00021
Huang Gang, Niu Giuzhi, Wang Xinlu, Guo Jun, Yu Feng. 2012.Formation and emplacement age of Karamaili ophiolite:LA-ICPMS zircon U-Pb age evidence from the diabase and tuff in eastern Junggar, Xinjiang[J]. Geological Bulletin of China, 31(8):1267-1278 (in Chinese with English abstract). https://www.researchgate.net/publication/292683658_LA-ICP-MS_zircon_U-Pb_dating_of_the_Kubusunan_granodiorite_in_the_Kalamaili_area_eastern_Junggar_Xinjiang
Irvine T N, Baragar W A R. 1971. A guid to the chemical classification of the common volcanic rocks[J]. Canadian Journal of Earth Sciences, 8:523-548. doi: 10.1139/e71-055
Jiří Sláma, Jan Košler, Daniel J Condon, James L Crowley, Axel Gerdes, John M Hanchar, Matthew S A Horstwood, George AMorris, Lutz Nasdala, Nicholas Norberg, Urs Schaltegger, Blair Schoene, Michael N Tubrett, Martin J Whitehouse. 2008. Plešovice zircon:A new natural reference material for U-Pb and Hf isotopic microanalysis[J]. Chemical Geology, 249, 1-35 doi: 10.1016/j.chemgeo.2007.11.005
Li Jinyi, Yang Tiannan, Li Yaping, Zhu Zhixin. 2009. Geological features of the Karamaili faulting belt, Easern Junggar region, Xinjiang, China and its constraints on the reconstruction of Late Paleozoic ocean-continental framework of the Central Asian Region[J]. Geological Bulletin of China, 28(12):1817-1826 (in Chinese with English abstract). https://www.researchgate.net/publication/232979656_Xinjiang_and_its_Central_Asian_borderlands
Li Jinyi, Zhu Baoqing, Fen Yimin. 1989. Confirmation of the unconformity relationships between the Nanmingshui Formation and ophiolites and their significance[J]. Regional Geology of China, 3:250-255 (in Chinese with English abstract).
Li Jinyi. 1995. Main characteristics and Emplacement processes of the East Junggar ophiolites, Xinjing, China[J]. Acta Petrologica Sinica, 11(supp.):73-84 (in Chinese with English abstract).
Liang Yunhai, Li Wenqian, Li Weidong, Li Yaping. 1999. Ophiolitic emplacement mechanism of Xinjiang[J]. Xinjiang Geology, 17(4):344-349(in Chinese with English abstract).
Li X H, Liu Y, Li Q L, Guo C H and Chamberlain K R.. 2009. Precise determination of Phanerozoic zircon Pb/Pb ageby multicollector SIMS without external standardization, Geochem[J]. Geophys.Geosyst, 10, Q04010, doi:10.1029/2009GC002400.
Liu Xijun, Xu Jifeng, Hou qingye, Bai Zhenghua, Lei Min. 2007.Geochemical characteristics of Karamaili ophiolite in east Junggar, Xinjiang:Products of ridge subduction[J]. Acta Petrologica Sinica, 23(7):1591-1602(in Chinese with English abstract). https://www.researchgate.net/publication/279891839_Geochemical_characteristics_of_Karamaili_ophiolite_in_east_Junggar_Xingjiang_Products_of_ridge_subduction
Long X P, Yuan C, Sun M. 2012. Geochemistry and U-Pb detrital zircon dating of Paleozoic graywackes in East Junggar, NW China:Insights into subduction-accretion processes in the southern Central Asian Orogenic Belt[J]. Gondwana Research, 21:637-653. doi: 10.1016/j.gr.2011.05.015
Ludwig K R. 2003. User's Manual for isoplot 3.00[J]. Berkeley Geochronology Center Special Publication, 4:46. https://www.researchgate.net/publication/301951506_User's_Manual_for_IsoplotEx_rev_300_A_Geochronological_Toolkit_for_Microsoft_Excel
Masra S N. 1971. Chemical distinction of high-grade ortho-and parametabasite[J]. Norsk Geologisk Tidsskrift, 51:311-316. https://www.researchgate.net/profile/Brian_Whalley/publication/259359612_Observations_on_the_Kaiserstuhl_Loess/links/560574e008aeb5718ff16d51.pdf
Pearce J A, Cann J R. 1973. Tectonic setting of basic volcanic rocks determined using trace element analysis[J]. Earth and Planetary Science Letters, 19:290-300. doi: 10.1016/0012-821X(73)90129-5
Pearce J A, Peate D W. 1995. Tectonic implications of the composition of volcanic arc magmas[J]. Annual Review of Earth and Planetary Sciences, 23:251-285 doi: 10.1146/annurev.ea.23.050195.001343
Sengör A M C, Natal'in B. 1996. Turkic-type orogeny and its role in the making of the continental crust[J]. Annual Reviews of Earth and Planetary Sciences, 24:263-337. doi: 10.1146/annurev.earth.24.1.263
Shervais J W. 1982. Ti-V plots and the petrogenesis of modern and ophiolitic lavas[J]. Earth and Planetary Science Letters, 31:457-484 https://www.researchgate.net/publication/222439998_Ti-V_plots_and_the_petrogenesis_of_modern_ophiolitic_lavas
Shu Liangshu, Wang Yujing. 2003. Late Devonian-Early Carboniferous radiolarian fossils from siliceous rocks of the Kelamaili ophiolite, Xinjiang[J]. Geological Review, 49 (4):408-412 (in Chinese with English abstract). https://www.researchgate.net/publication/284318300_Late_Devonian-Early_Carboniferous_radiolarian_fossils_from_siliceous_rocks_of_the_Kelameili_ophiolite_Xinjiang
Sun S S, McDonough W F. 1989. Chemical and isotopic systematics of oceanic basalts:Implication for mantle composition and processes[C]//Saunder A D, Norry M J, eds. Magmatism in the Ocean Basins[J]. Geological Society London Special Publications, 42:313-345.
Tang Hongfeng, Su Yuping, Liu Congqiang, Hou Guangshun, Wang Yanbin. 2007. Zircon U-Pb age of the plagiogranite in Kalamaili belt, northern Xinjiang and its tectonic implications[J]. Geotectonica et Metallogenia, 31(1):110-117 (in Chinese with English abstract). https://www.researchgate.net/publication/284264155_Zircon_U-Pb_age_of_the_plagiogranite_in_Kalamaili_belt_northern_Xinjiang_and_its_tectonic_implications
Tian Jian, Liao Qunan, Fan Guangming, Nie Xiaomei, Wang Fuming. 2015. The discovery and tectonic implication of Early Carboniferous post-collisional Ⅰ-type granites from the south of Karamaili in eastern Junngar[J]. Acta Petrologica Sinica, 31(5):1471-1484(in Chinese with English abstract). https://www.researchgate.net/profile/Guilan_Fan/citations?sorting=citationCount&page=1
Wang Bangyao, Jiang Changyi, Li Yongjun, Wu Hongen, Xia Zhaode, Lu Ronghui. 2009. Kalamaili East Junggar ophiolites geochemical characteristics and tectonic significance[J]. Acta Petrological et Mineralogica, 29(3):74-82 (in Chinese with English abstract). https://www.researchgate.net/publication/283409996_Geochemical_characteristics_and_tectonic_significance_of_Kalamaili_SSZ_ophiolite_from_eastern_Junggar
Wang Fuming, Liao Qunan, Fan Guangming, Chen Wenjuan, Tian Jian, Chen Shuai, Wu Weiwei, Hu Chaobin. 2014. Geological implications of unconformity between Upper and Middle Devonian, and 346.8 Ma post-collision volcanic rocks in Karamaili, Xinjiang[J]. Earth Science——Journal of China University of Geosciences, 39(9):1243-1257 (in Chinese with English abstract). https://www.researchgate.net/profile/Xingwang_Xu2/citations?sorting=citationCount&page=2
Wang Yong, Chen Wanfeng, Sha Xin, Zhai Xinwei, Wang Jinrong. 2014. The petrological characteristics and tectonic implications of Jiangbasitao Formation in Eastern Junggar, Xinjiang[J]. Gansu Geology, 23(4):41-45 (in Chinese with English abstract). https://www.researchgate.net/publication/286297367_Geochemical_characteristics_and_tectonic_implications_of_Karamaili_Jiangbasitao_Formation_volcanic_rock_in_Xinjiang
Winchester J A, Floyd P A. 1977. Geochemical discrimination of different magma series and their differentiation products using immobile elements[J]. Chemical Geology, 20:325-343. doi: 10.1016/0009-2541(77)90057-2
Wood D A. 1980. The application of a Th-Hf-Ta diagram to problems of tectonomagmatic classification and to establishing the nature of crustal contamination of basaltic lavas of the British Tertiary volcanic province[J]. Earth and Planetary Science Letters, 50:11-30. doi: 10.1016/0012-821X(80)90116-8
Wu Runjiang, Zhang Yuanyuan, Tan Jiayi, Guo Zhaojie. 2009. The characteristics of different structure layers and tectonic implications since Late Paleozoic in Kalamaily area, Xinjiang[J]. Earth Science Frontiers, 16(3):102-109 (in Chinese with English abstract). https://www.researchgate.net/publication/292066153_The_characteristics_of_different_structure_layers_and_tectonic_implications_since_late_Paleozoic_in_Kalamaily_area_Xinjiang
Xiao W J, Zhang L C, Qin K Z, Qin K Z, Sun S, Li J L. 2004.Paleozoic accretionary and collisional tectonics of the eastern Tianshan (China):Implications for the continental growth of central Asia[J]. American Journal of Science, 304:370-395. doi: 10.2475/ajs.304.4.370
Xiao W J, Han C M, Yuan C, SunM, Lin S F, Chen H L, Li Z L, Li J L, Sun S. 2008. Middle Cambrian to Permian subduction-related accretionary orogenesis of Northern Xinjiang, NW China:Implications for the tectonic evolution of central Asia[J]. Journal of Asian Earth Sciences, 32:102-117. doi: 10.1016/j.jseaes.2007.10.008
Xu X W, Jiang N, Li X H, Wu C, Qu X, Zhou G, Dong L H. 2015. Spatial-temporal framework for the closure of the Junggar Ocean in central Asia:New SIMS zircon U-Pb ages of the ophiolitic mélange and collisional igneous rocks in the Zhifang area, East Junggar[J]. Journal of Asian Earth Sciences, 111:470-491. doi: 10.1016/j.jseaes.2015.06.017
Xu Xueyi, Li Rongshe, Chen Juanlu, Ma Zhongping, Li Zhipei, Wang Hongliang, Bai Jianke, Tang Zhuo. 2014. New constrains on the Palezoic tectonic evolution of the northern Xinjiang area[J]. Acta Petrologica Sinica, 30(6):1521-1534 (in Chinese with English abstract).
Zhao Zhenhua. 1997. Geochemical Theory of Trace Element[M]. Beijing:Science Press, 65-67 (in Chinese with English abstract).
Zhu Yunhai, Pan Yuanming, Zhang Kexin, Wang Guocan, Chen Nengsong, Hou Guangjiu. 2000. Emplacement mechanisms of ophiolites and their characteristics[J]. Geological Science and Technology Information, 19(1):16-18(in Chinese with English abstract). https://www.researchgate.net/profile/John_Wakabayashi/publication/240675386_What_constitutes_%27emplacement%27_of_an_ophiolite_Mechanisms_and_relationship_to_subduction_initiation_and_formation_of_metamorphic_soles/links/555f919e08ae6f4dcc9270ff.pdf?origin=publication_detail
方爱民, 王世刚, 张俊敏, 藏梅, 方家虎, 胡健明. 2015.新疆北部卡拉麦里蛇绿岩中辉长岩的锆石U-Pb年龄及其构造意义[J].地质科学, 50(1):140-154. http://www.cnki.com.cn/Article/CJFDTOTAL-DZKX201501009.htm
何国琦, 李茂松, 贾进斗, 周辉. 2001.论新疆东准噶尔蛇绿岩的时代及其意义[J].北京大学学报(自然科学版), 37 (6):852-858. http://www.cnki.com.cn/Article/CJFDTOTAL-BJDZ200106017.htm
胡朝斌, 廖群安, 樊光明, 陈帅, 吴魏伟, 田健, 王富明. 2014.东准噶尔滴水泉地区发现洋中脊型蛇绿岩[J].科学通报, 22:2213-2224. http://www.cnki.com.cn/Article/CJFDTOTAL-KXTB201422010.htm
黄岗, 牛广智, 王新录, 郭俊, 宇峰. 2012.新疆东准噶尔卡拉麦里蛇绿岩的形成和侵位时限-来自辉绿岩和凝灰岩LA-ICP-MS锆石U-Pb年龄的证据[J].地质通报, 31(8):1267-1278. http://www.cnki.com.cn/Article/CJFDTOTAL-ZQYD201208006.htm
李锦轶, 杨天南, 李亚萍, 朱志新. 2009.东准噶尔卡拉麦里断裂带的地质特征及其对中亚地区晚古生代洋陆格局重建的约束[J].地质通报, 28(12):1817-1826. doi: 10.3969/j.issn.1671-2552.2009.12.014
李锦轶, 朱宝清, 冯益民. 1989.南明水组和蛇绿岩之间不整合关系的确认及其意义[J].中国区域地质, 3:250-255. http://www.cnki.com.cn/Article/CJFDTOTAL-ZQYD198903009.htm
李锦轶. 1995.新疆东准噶尔蛇绿岩的基本特征和侵位历史[J].岩石学报, 11(增刊):73-84. http://www.cnki.com.cn/Article/CJFDTOTAL-YSXB5S1.005.htm
梁云海, 李文铅, 李卫东, 李亚萍. 1999.新疆蛇绿岩就位机制[J].新疆地质, 17(4):344-349. http://www.cnki.com.cn/Article/CJFDTOTAL-XJDI199904008.htm
刘希军, 许继峰, 侯青叶, 白正华, 雷敏. 2007.新疆东准噶尔克拉麦里蛇绿岩地球化学:洋脊俯冲的产物[J].岩石学报, 23(7):1591-1602. http://www.cnki.com.cn/Article/CJFDTOTAL-YSXB200707003.htm
舒良树, 王玉净. 2003.新疆卡拉麦里蛇绿岩带中硅质岩的放射虫化石[J].地质论评, 49 (4):408-412. http://www.cnki.com.cn/Article/CJFDTOTAL-DZLP200304010.htm
唐红峰, 苏玉平, 刘丛强, 候广顺, 王彦斌. 2007.新疆北部卡拉麦里斜长花岗岩的锆石U-Pb年龄及其构造意义[J].大地构造与成矿学, 2007, 31(1):110-117. http://www.cnki.com.cn/Article/CJFDTOTAL-DGYK200701014.htm
田健, 廖群安, 樊光明, 聂小妹, 王富明. 2015.东准噶尔卡拉麦里断裂以南早石炭世后碰撞花岗岩的发现及其地质意义[J].岩石学报, 31(5):1471-1484 http://www.cnki.com.cn/Article/CJFDTOTAL-YSXB201505021.htm
汪帮耀, 姜常义, 李永军, 吴宏恩, 夏昭德, 卢荣辉. 2009.新疆东准噶尔卡拉麦里蛇绿岩的地球化学特征及大地构造意义[J].矿物岩石, 29(3):74-82. http://www.cnki.com.cn/Article/CJFDTOTAL-KWYS200903011.htm
王富明, 廖群安, 樊光明, 程雯娟, 田健, 陈帅, 吴魏伟, 胡朝斌. 2014.新疆卡拉麦里上-中泥盆统间角度不整合和346.8Ma后碰撞火山岩的意义[J].地球科学——中国地质大学学报, 39(9):1243-1257. http://www.cnki.com.cn/Article/CJFDTOTAL-DQKX201409001.htm
王勇, 陈万峰, 沙鑫, 翟新伟, 王金荣. 2014.新疆东准噶尔地区姜巴斯套组岩石学特征及构造意义[J].甘肃地质, 23(4):41-45. http://www.cnki.com.cn/Article/CJFDTOTAL-GSDZ201404007.htm
吴润江, 张元元, 谭佳奕, 郭召杰. 2009.新疆卡拉麦里地区晚古生代以来不同构造层特征及大地构造意义[J].地学前缘, 16(3):102-109. http://www.cnki.com.cn/Article/CJFDTOTAL-DXQY200903011.htm
徐学义, 李荣社, 陈隽璐, 马中平, 李智佩, 王洪亮, 白建科, 唐卓. 2014.新疆北部古生代构造演化的几点认识[J].岩石学报, 30(6):1521-1534. http://www.cnki.com.cn/Article/CJFDTOTAL-YSXB201406001.htm
赵振华. 1997.微量元素地球化学原理[M].北京:科学出版社, 65-67.
朱云海, 潘元明, 张克信, 王国灿, 陈能松, 侯光久. 2000.蛇绿岩就位机制研究[J].地质科技情报, 19(1):16-18. http://www.cnki.com.cn/Article/CJFDTOTAL-DZKX201103021.htm
-
图(10)
表(2)
计量
- 文章访问数: 2835
- PDF下载数: 1244
- 施引文献: 0