Discovery of Bimodal Volcanics and Its Geological Significance in the Xiemisitai Region, Western Junggar, China

doi:10.19657/j.geoscience.1000-8527.2018.04.06

Abstract

Abstract:

The Xiemisitai region in the Western Junggar is a key region to investigate the tectonic evolution of the Junggar ocean basin. The discovery of the Xiemisitai bimodal volcanics and their composition, petrogeochemistry, and zircon U-Pb age are important to discriminate formation mechanism and tectonic setting, reconstruct the tectonic framework of Western Junggar orogenic belt. The following acquaintances were obtained by this paper.The bimodal volcanics are composed of alkaline basalt and calc-alkaline rhyolite, and the LA-ICP-MS zircon U-Pb dating of the rhyolite is (431.8±2.3) Ma. The mafic magma was likely derived from partial melting of the mantle metasomatized by subduction-related fluid, and the felsic magma was derived from the partial melting of crust materials. The bimodal volcanics may have formed in an early Silurian incipient back-arc basin. Combined with previous studies, we suggest that there was a complete Early Paleozoic trench-arc-basin system in the Xiemisitai region, Western Junggar.

Key words: bimodal volcanics, geochemistry, zircon U-Pb dating, trench-arc-basin system, Western Junggar

CLC Number:

P588.1

WENG Kai, MA Zhongping, ZHANG Xue. Discovery of Bimodal Volcanics and Its Geological Significance in the Xiemisitai Region, Western Junggar, China[J]. Geoscience, 2018, 32(04): 692-703.

Figures/Tables 11

References 47

[1]	DALY R A. The geology of Ascension Island[J]. Proceedings of the American Academy of Arts and Sciences, 1925, 60(1): 50-80.
[2]	HILDRETH W. Gradients in silicic magma chambers: Implications for lithospheric magmatism[J]. Journal of Geophysical Research, 1981, 86: 10153-10192. DOI URL
[3]	BROPHY J G. Composition gaps, critical crystallinity, and fractional crystallization in orogenic (calc-alkaline) magmatic systems[J]. Contributions to Mineralogy and Petrology, 1991, 109(2): 173-182. DOI URL
[4]	CHRISTIAN P, PAQUETTE J L. A mantle-derived bimodal suite in the Hercynian Belt: Nd isotope and trace element evidence for a subduction-related rift origin of the Late Devonian Brevenne metavolcanics, Massif Central (France)[J]. Contributions to Mineralogy and Petrology, 1997, 129(2): 222-238. DOI URL
[5]	GEIST D, HOWARD K A, LARSON P. The generation of oceanic rhyolites by crystal fractionation: the basalt-rhyolite association at Volcan Alcedo, Galapagos Archipelago[J]. Journal of Petrolo-gy, 1995, 36(4): 965-982.
[6]	GARLAND F, HAVKESWORTH C J, MANTOVANI M S M. Description and petrogenesis of the Parana Rhyolites, Southern Brazil[J]. Journal of Petrology, 1995, 36(5): 1193-1227. DOI URL
[7]	HARRIS L. The deep layers of a Paleozoic arc geochemistry of the Copley-Balaklala series, northern California[J]. Earth & Planetary Science Letters, 1987, 85(4): 386-400.
[8]	HOCHSTAEDTER A G, GILL J B, MORRIS J D. Volcanism in the Sumisu Rift, II. Subduction and non-subduction related components[J]. Earth & Planetary Science Letters, 1990, 100(1/3): 195-209.
[9]	COULON C, MALUSKI H, BOLLINGER C, et al. Mesozoic and Cenozoic volcanic rocks from central and southern Tibet:³⁹Ar-⁴⁰Ar dating, petrological characteristics and geodynamical significance[J]. Earth & Planetary Science Letters, 1986, 79(3/4): 281-302.
[10]	钱青, 王焰. 不同构造环境中双峰式火山岩的地球化学特征[J]. 地质地球化学, 1999, 27(4): 29-32.
[11]	王焰, 钱青, 刘良, 等. 不同构造环境中双峰式火山岩的主要特征[J]. 岩石学报, 2000, 16(2): 169-173.
[12]	吕晓春, 任冲, 武睿, 等. 藏南隆子地区早白垩世双峰式火山岩的发现——来自SHRIMP锆石U-Pb年代学和锆石地球化学的证据[J]. 地质论评, 2016, 62(4): 945-954.
[13]	陈根文, 邓腾, 刘睿, 等. 西天山阿吾拉勒地区二叠系塔尔得套组双峰式火山岩地球化学研究[J]. 岩石学报, 2015, 31(1): 105-118.
[14]	耿新霞, 柴凤梅, 杨富全, 等. 新疆阿尔泰南缘达拉乌兹双峰式火山岩年龄及岩石成因[J]. 岩石学报, 2010, 26(10): 2967-2980.
[15]	王银喜, 顾连兴, 张遵忠, 等. 博格达裂谷双峰式火山岩地质年代学与Nb-Sr-Pb同位素地球化学特征[J]. 岩石学报, 2006, 22(5): 1215-1225.
[16]	刘书生, 范文玉, 罗茂金, 等. 老挝南部帕莱通双峰式火山岩锆石U-Pb定年及岩石地球化学特征[J]. 吉林大学学报(地球科学版), 2014, 44(2): 540-553.
[17]	陈彦, 张志诚, 李可, 等. 内蒙古西乌旗地区二叠纪双峰式火山岩的年代学、地球化学特征和地质意义[J]. 北京大学学报(自然科学版), 2014, 50(5): 843-856.
[18]	WINDLEY B F, ALEXEIEV D, XIAO W J, et al. Tectonic models for accretion of the Central Asian Orogenic Belt[J]. Journal of the Geological Society, 2007, 164(12): 31-47. DOI URL
[19]	孟磊, 申萍, 沈远超. 新疆谢米斯台中段火山岩岩石地球化学特征、锆石U-Pb年龄及其地质意义[J]. 岩石学报, 2010, 26(10): 3047-3056.
[20]	SHEN P, SHEN Y C, LI X H, et al. Northwestern Junggar Basin, Xiemisitai Mountains, China: A geochemical and geochronological approach[J]. Lithos, 2012, 140/141: 103-118. DOI URL
[21]	LUDWIG R K. ISOPLOT: A plotting and regression program for radiogenic-isotope data. Version 2.53[R]. Reston:U.S.Geological Survey, 1998: 1-40.
[22]	ANDERSEN T. Correction of common lead in U-Pb analyses that do not report ²⁰⁴Pb[J]. Chemical Geology, 2002, 192(1/2): 59-79. DOI URL
[23]	VAN ACHTERBERGH E, RYAN C G, JACKSON S E, et al. Data reduction software for LA-ICP-MS[M]// SYLVESTER P J. Laser-Ablation-ICPMS in the Earth Sciences:Principles and Applications. Ottawa: Mineralogical Association of Canada, 2001: 239-243.
[24]	YUAN H L, GAO S, LIU X M, et al. Accurate U-Pb age and trace element determinations of zircon by laser ablation inductively coupled plasma-mass spectrometry[J]. Geostandards and Geoanalytical Research, 2004, 28(3): 353-370. DOI URL
[25]	WANG X L, ZHOU J C, QIU J S, et al. LA-ICP-MS U-Pb zircon geochronology of the Neoproterozoic igneous rocks from Northern Guangxi, South China: Implications for tectonic evolution[J]. Precambrian Research, 2006, 145(1/2): 111-130. DOI URL
[26]	BOYNTON W V. Geochemistry of the rare earth elements: Meteorite studies[M]//HENDERSON P. Rare Earth Element Geochemistry. Amsterdam: Elsevier, 1984: 63-114.
[27]	SUN S S, MCDONOUGH W F. Chemical and isotopic systematics of oceanic basalts: Implications for mantle composition and processes[M]// SAUNDERSA D, NORRYM J. Magmatism in Oceanic Basins. London: Geological Society of London, 1989: 313-345.
[28]	GROVE T L, DONNELLY-NOLAN J M. The evolution of young silicic lavas at Medicine Lake Volcano, California: implications for the origin of compositional gaps in calc-alkaline series lavas[J]. Contributions to Mineralogy and Petrology, 1986, 92(3): 281-302. DOI URL
[29]	MACDONALD R. Quaternary peralkaline silicic rocks and caldera volcanoes of Kenya[M]// FITTONJ G, UPTONB G J. Alkaline Igneous Rocks. London: Geological Society of London, 1987: 313-333.
[30]	李献华, 周汉文, 李正祥, 等. 川西新元古代双峰式火山岩成因的微量元素和Sm-Nd同位素制约及其大地构造意义[J]. 地质科学, 2002, 37(3): 264-276.
[31]	SHINJO R, KATO Y. Geochemical constraints on the origin of bimodal magmatism at the Okinawa Trough, an incipient back-arc basin[J]. Lithos, 2000, 54(3/4): 117-137. DOI URL
[32]	DOE B R, LEEMAN W P, CHRISTIANSEN R L, et al. Lead and strontium isotopes and related trace elements as genetic tracers in the Upper Cenozoic rhyolite-basalt association of the Yellowstone plateau volcanic field[J]. Journal of Geophysical Research Atmospheres, 1982, 87(B6): 4785-4806. DOI URL
[33]	HUPPERT H E, SPARKS R S J. The generation of granitic magmas by intrusion of basalt into continental crust[J]. Journal of Petrology, 1988, 29(3): 599-624. DOI URL
[34]	DAVIES G R, MACDONALD R. Crustal influences in the petrogenesis of the Naivasha basalt-comendite complex: Combined trace element and Sr-Nd-Pb isotope constraints[J]. Journal of Petrology, 1987, 28(6): 1009-1031. DOI URL
[35]	WENDLANDT R F, ALTHERR R, NEUMANN E R, et al. Petrology, Geochemistry, isotopes[M]// OLSENK H. Continental Rifts:Evolution, Structure, Tectonics. Amsterdam: Elsevier, 1995: 47-60.
[36]	LIGHTFOOT P C, NALDRETT A J, GORBACHEV N S, et al. Geochemistry of the Siberian Trap of the Noril’sk area, USSR, with implications for the relative contributions of crust and mantle to flood basalt magmatism[J]. Contributions to Mineralogy and Petrology, 1990, 104(6): 631-644. DOI URL
[37]	周刚, 秦纪华, 张招崇, 等. 新疆富蕴苏普特一带双峰式火山岩的发现及其地质意义[J]. 地质论评, 2007, 53(3): 337-348.
[38]	BEN O D, WHITE W M, PATCHETT J. The geochemistry of marine sediments, island arc magma genesis, and crust-mantle recycling[J]. Earth & Planetary Science Letters, 1989, 94(1/2): 1-21.
[39]	PEARCE J A, LIPPARD S J, ROBERTS S. Characteristics and tectonic significance of supra-subduction zone ophiolites[M]// KOKELAARB P, HOWELLSM F. Marginal Basin Geology. London: Geological Society of London, 1984: 77-94.
[40]	CONDIE K C. Geochemical changes in basalts and andesites across the archaean-proterozoic boundary: identification and significance[J]. Lithos, 1989, 23(1/2):1-18. DOI URL
[41]	GERTISSER R, KELLER J. Trace element and Sr, Nd, Pb and O isotope variations in medium-K and high-K volcanic rocks from Merapi volcano, Central Java, Indonesia: Evidence for the involvement of subducted sediments in Sunda Arc magma genesis[J]. Journal of Petrology, 2003, 44(3):457-489. DOI URL
[42]	PEARCE J A, KEMPTON P D, NOWELL G M, et al. Hf-Nd element and isotope perspective on the nature and provenance of mantle and subduction components in Western Pacific arc-basin systems[J]. Journal of Petrology, 1999, 40(11): 1579-1611. DOI URL
[43]	EWART A, COLLERSON K D, REGELOUS M, et al. Geochemical evolution within the Tonga-Kermadec-Lau arc-back-arc systems: the role of varying mantle wedge composition in space and time[J]. Journal of Petrology, 1998, 39(3): 331-368. DOI URL
[44]	TAYLOR R N, LAPIERRE H, VIDAL P, et al. Igneous geochemistry and petrogenesis of the Izu-Bonin forearc basin[J]. Proceedings of the Ocean Drilling Program, 1992, 126: 405-430.
[45]	PEARCE J A, HARRIS N B W, TINDLE A G. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks[J]. Journal of Petrology, 1984, 25(4): 956-983. DOI URL
[46]	赵磊, 何国琦, 朱亚兵. 新疆西准噶尔北部谢米斯台南坡蛇绿岩带的发现及其意义[J]. 地质通报, 2013, 32(1): 195-205.
[47]	CHEN J F, HAN B F, JI J Q, et al. Zircon U-Pb ages and tectonic implications of Paleozoic plutons in northern West Junggar, North Xinjiang, China[J]. Lithos, 2010, 115(1/4): 137-152. DOI URL

地层				主要岩石组合	化石
界	系	组	代号	主要岩石组合	化石
古生界	石炭系	洪古勒楞组	D₃C₁h	生物碎屑灰岩、钙质灰岩、泥质灰岩	腕足、珊瑚、海百合茎、苔藓虫
	石炭系	朱鲁木特组	D₃z	砾岩、含砾中粗砂岩、中粗砂岩	陆相植物化石
	泥盆系	朱鲁木特组	D₃z	砾岩、含砾中粗砂岩、中粗砂岩	陆相植物化石
		塔克台组	D₃tk	火山岩、火山碎屑岩、砂砾岩、煤层	陆相植物化石、腕足、珊瑚、海百合茎、苔藓虫
		呼吉尔斯特组	D₂h	砂砾岩夹粉砂岩
		沙尔布尔组	S₂s	生物碎屑灰岩、凝灰质砂砾岩、沉凝灰岩、安山玄武质火山角砾熔岩等
	志留系	沙尔布尔组	S₂s	生物碎屑灰岩、凝灰质砂砾岩、沉凝灰岩、安山玄武质火山角砾熔岩等
	志留系	谢米斯台组	S_1-4x	安山岩、流纹岩、玄武岩、火山角砾岩、含角砾凝灰岩、凝灰岩、凝灰质砂岩等

地层				主要岩石组合	化石
界	系	组	代号	主要岩石组合	化石
古生界	石炭系	洪古勒楞组	D₃C₁h	生物碎屑灰岩、钙质灰岩、泥质灰岩	腕足、珊瑚、海百合茎、苔藓虫
	石炭系	朱鲁木特组	D₃z	砾岩、含砾中粗砂岩、中粗砂岩	陆相植物化石
	泥盆系	朱鲁木特组	D₃z	砾岩、含砾中粗砂岩、中粗砂岩	陆相植物化石
		塔克台组	D₃tk	火山岩、火山碎屑岩、砂砾岩、煤层	陆相植物化石、腕足、珊瑚、海百合茎、苔藓虫
		呼吉尔斯特组	D₂h	砂砾岩夹粉砂岩
		沙尔布尔组	S₂s	生物碎屑灰岩、凝灰质砂砾岩、沉凝灰岩、安山玄武质火山角砾熔岩等
	志留系	沙尔布尔组	S₂s	生物碎屑灰岩、凝灰质砂砾岩、沉凝灰岩、安山玄武质火山角砾熔岩等
	志留系	谢米斯台组	S_1-4x	安山岩、流纹岩、玄武岩、火山角砾岩、含角砾凝灰岩、凝灰岩、凝灰质砂岩等

点号	Th/ (μg·g^-1)	U/ (μg·g^-1)	Th/U	²⁰⁷Pb/²⁰⁶Pb		²⁰⁷Pb/²³⁵U		²⁰⁶Pb/²³⁸U		²⁰⁸Pb/²³²Th		谐和年龄		谐和度/%
点号	Th/ (μg·g^-1)	U/ (μg·g^-1)	Th/U	比值	1s	比值	1s	比值	1s	比值	1s	年龄/Ma	1s	谐和度/%
NO1	169.70	223.19	0.76	0.055 84	0.001 46	0.536 87	0.013 00	0.069 80	0.000 54	0.020 61	0.000 26	435	3	100.23
NO2	231.75	299.94	0.77	0.055 47	0.001 51	0.532 96	0.013 55	0.069 75	0.000 57	0.020 27	0.000 26	435	3	99.77
NO3	107.52	192.79	0.56	0.055 62	0.001 70	0.534 18	0.015 38	0.069 72	0.000 62	0.020 66	0.000 35	434	4	100.23
NO4	104.71	188.16	0.56	0.055 93	0.004 77	0.534 16	0.044 45	0.069 32	0.001 59	0.022 38	0.001 05	432	10	100.69
NO5	483.02	670.95	0.72	0.056 35	0.002 57	0.542 27	0.023 87	0.069 84	0.000 89	0.021 32	0.000 50	435	5	101.15
NO6	223.50	252.20	0.89	0.055 40	0.002 22	0.516 51	0.019 83	0.067 64	0.000 76	0.018 88	0.000 35	422	5	100.24
NO7	248.10	286.40	0.87	0.055 46	0.001 49	0.523 40	0.013 08	0.068 47	0.000 54	0.021 18	0.000 27	427	3	100.00
NO8	421.77	435.56	0.97	0.056 43	0.005 76	0.529 91	0.052 91	0.068 13	0.001 87	0.019 99	0.001 03	425	11	101.65
NO9	81.95	156.72	0.52	0.055 09	0.008 18	0.517 62	0.075 32	0.068 16	0.002 67	0.020 82	0.001 77	425	16	99.76
NO10	107.58	184.32	0.58	0.055 21	0.005 05	0.517 92	0.046 25	0.068 04	0.001 65	0.021 17	0.000 99	424	10	100.00
NO11	223.60	328.99	0.68	0.055 25	0.009 35	0.527 95	0.087 60	0.069 31	0.003 10	0.023 31	0.001 66	432	19	99.54
NO12	274.06	386.41	0.71	0.055 42	0.006 94	0.533 42	0.065 43	0.069 80	0.002 33	0.022 59	0.001 42	435	14	99.77
NO13	177.19	312.27	0.57	0.055 31	0.004 03	0.517 88	0.036 80	0.067 91	0.001 33	0.021 15	0.000 85	424	8	100.00
NO14	275.33	385.13	0.71	0.055 64	0.003 13	0.534 96	0.029 19	0.069 72	0.001 07	0.021 05	0.000 60	434	6	100.23
NO15	177.77	339.49	0.52	0.055 89	0.009 42	0.538 34	0.088 96	0.069 84	0.003 13	0.023 96	0.002 38	435	19	100.46
NO16	293.27	513.05	0.57	0.055 87	0.002 45	0.539 58	0.022 80	0.070 03	0.000 85	0.021 68	0.000 53	436	5	100.46
NO17	235.40	385.94	0.61	0.055 58	0.001 63	0.535 87	0.014 76	0.069 91	0.000 60	0.021 79	0.000 34	436	4	100.00
NO18	104.97	191.61	0.55	0.055 67	0.002 16	0.529 46	0.019 69	0.068 96	0.000 74	0.021 45	0.000 45	430	4	100.23
NO19	93.82	205.60	0.46	0.055 80	0.003 32	0.522 24	0.030 16	0.067 85	0.001 09	0.021 84	0.000 63	423	7	100.95
NO20	78.50	168.87	0.46	0.056 08	0.007 54	0.527 99	0.069 51	0.068 26	0.002 43	0.022 49	0.001 44	426	15	100.94

点号	Th/ (μg·g^-1)	U/ (μg·g^-1)	Th/U	²⁰⁷Pb/²⁰⁶Pb		²⁰⁷Pb/²³⁵U		²⁰⁶Pb/²³⁸U		²⁰⁸Pb/²³²Th		谐和年龄		谐和度/%
点号	Th/ (μg·g^-1)	U/ (μg·g^-1)	Th/U	比值	1s	比值	1s	比值	1s	比值	1s	年龄/Ma	1s	谐和度/%
NO1	169.70	223.19	0.76	0.055 84	0.001 46	0.536 87	0.013 00	0.069 80	0.000 54	0.020 61	0.000 26	435	3	100.23
NO2	231.75	299.94	0.77	0.055 47	0.001 51	0.532 96	0.013 55	0.069 75	0.000 57	0.020 27	0.000 26	435	3	99.77
NO3	107.52	192.79	0.56	0.055 62	0.001 70	0.534 18	0.015 38	0.069 72	0.000 62	0.020 66	0.000 35	434	4	100.23
NO4	104.71	188.16	0.56	0.055 93	0.004 77	0.534 16	0.044 45	0.069 32	0.001 59	0.022 38	0.001 05	432	10	100.69
NO5	483.02	670.95	0.72	0.056 35	0.002 57	0.542 27	0.023 87	0.069 84	0.000 89	0.021 32	0.000 50	435	5	101.15
NO6	223.50	252.20	0.89	0.055 40	0.002 22	0.516 51	0.019 83	0.067 64	0.000 76	0.018 88	0.000 35	422	5	100.24
NO7	248.10	286.40	0.87	0.055 46	0.001 49	0.523 40	0.013 08	0.068 47	0.000 54	0.021 18	0.000 27	427	3	100.00
NO8	421.77	435.56	0.97	0.056 43	0.005 76	0.529 91	0.052 91	0.068 13	0.001 87	0.019 99	0.001 03	425	11	101.65
NO9	81.95	156.72	0.52	0.055 09	0.008 18	0.517 62	0.075 32	0.068 16	0.002 67	0.020 82	0.001 77	425	16	99.76
NO10	107.58	184.32	0.58	0.055 21	0.005 05	0.517 92	0.046 25	0.068 04	0.001 65	0.021 17	0.000 99	424	10	100.00
NO11	223.60	328.99	0.68	0.055 25	0.009 35	0.527 95	0.087 60	0.069 31	0.003 10	0.023 31	0.001 66	432	19	99.54
NO12	274.06	386.41	0.71	0.055 42	0.006 94	0.533 42	0.065 43	0.069 80	0.002 33	0.022 59	0.001 42	435	14	99.77
NO13	177.19	312.27	0.57	0.055 31	0.004 03	0.517 88	0.036 80	0.067 91	0.001 33	0.021 15	0.000 85	424	8	100.00
NO14	275.33	385.13	0.71	0.055 64	0.003 13	0.534 96	0.029 19	0.069 72	0.001 07	0.021 05	0.000 60	434	6	100.23
NO15	177.77	339.49	0.52	0.055 89	0.009 42	0.538 34	0.088 96	0.069 84	0.003 13	0.023 96	0.002 38	435	19	100.46
NO16	293.27	513.05	0.57	0.055 87	0.002 45	0.539 58	0.022 80	0.070 03	0.000 85	0.021 68	0.000 53	436	5	100.46
NO17	235.40	385.94	0.61	0.055 58	0.001 63	0.535 87	0.014 76	0.069 91	0.000 60	0.021 79	0.000 34	436	4	100.00
NO18	104.97	191.61	0.55	0.055 67	0.002 16	0.529 46	0.019 69	0.068 96	0.000 74	0.021 45	0.000 45	430	4	100.23
NO19	93.82	205.60	0.46	0.055 80	0.003 32	0.522 24	0.030 16	0.067 85	0.001 09	0.021 84	0.000 63	423	7	100.95
NO20	78.50	168.87	0.46	0.056 08	0.007 54	0.527 99	0.069 51	0.068 26	0.002 43	0.022 49	0.001 44	426	15	100.94

样号	岩石类型	SiO₂	Al₂O₃	Fe₂O₃	FeO	CaO	MgO	K₂O	Na₂O	TiO₂	P₂O₅	MnO	烧失量	总量	Mg^#
xms-1	玄武岩	49.75	15.12	9.99	0.62	7.42	1.24	0.63	7.37	1.30	0.36	0.25	5.75	99.80	60.67
xms-2	玄武岩	48.80	14.86	10.00	0.56	8.17	1.13	0.70	7.30	1.31	0.38	0.27	6.35	99.83	60.89
xms-3	玄武岩	49.59	15.38	10.10	0.83	7.08	1.03	1.22	7.04	1.33	0.38	0.24	5.59	99.81	48.91
xms-4	玄武岩	50.94	15.28	10.42	0.42	6.63	0.81	0.73	7.71	1.32	0.37	0.22	4.99	99.84	59.80
xms-5	流纹岩	73.20	13.00	2.35	0.48	0.73	0.38	4.05	4.46	0.24	0.05	0.06	0.81	99.80	37.92
xms-6	流纹岩	77.79	10.52	1.54	0.39	1.35	0.29	2.25	4.32	0.23	0.06	0.04	1.09	99.87	36.45