内蒙古中部苏尼特左旗地区勃勒金韧性剪切带的厘定及其地质意义

摘要/Abstract

摘要：

通过野外地质调查和室内显微构造分析,在内蒙古中部苏尼特左旗北部勃勒金一带厘定出一条NEE走向,往北倾,倾角70°~85°的左行逆冲型韧性剪切带。该韧性剪切带内发育糜棱岩系列、糜棱面理、拉伸线理、S-C组构、不对称褶皱、旋转碎斑、书斜构造和云母鱼构造等宏观和微观构造。野外观察表明,勃勒金韧性剪切带由若干条强变形带和其间的弱变形域组成,平面上呈现平行状展布,出露长约10 km,宽约4 km。在对韧性剪切带宏观、微观构造特征和锆石U-Pb年代学研究的基础上,结合区域资料,认为勃勒金韧性剪切带是区域上查干敖包—阿荣旗深断裂的构造形迹,形成于早二叠世早期(290~292 Ma),是古亚洲洋闭合、西伯利亚板块和华北板块南北向汇聚碰撞的产物。勃勒金韧性剪切带的厘定为兴蒙造山带晚古生代构造演化提供了基础资料。

关键词: 韧性剪切带, 早二叠世, 构造演化, 内蒙古中部, 兴蒙造山带

Abstract:

Based on the field geological investigation and microstructural observation, we recognized a NEE-striking sinistral thrust ductile shear zone in the Bolejin area of the north of Sonidzuoqi, central Inner Mongolia. The Bolejin ductile shear zone dips northward with angles of 70°-85°. There occur many typical macroscopic structures and microstructures such as mylonite rocks, mylonitic foliation, stretching lineation, S-C fabrics, asymmetrical folds, rotational porphyroclasts, domino structures and biotite-fishes in the ductile zone. In the light of field observation, the Bolejin ductile shear zone, about 10 km in length and 4 km in width, consists of several strong deformational zones and weak deformational domains. The deformational zones are approximately parallel to each other. The macroscopic structures, microstructures of the ductile shear zone, zircon U-Pb chronology, as well as regional geological data suggest that the Bolejin ductile shear zone is a structural feature of the Chaganobo-Arongqi fault. The shear zone was formed at 290-292 Ma in the early Early Permian. The Bolejin ductile shear zone resulted from the S-N collision between the North China and Siberian plates after the final closure of the Paleo-Asian Ocean. Thus, the determination of the Bolejin ductile shear zone has provided constraints on the Late Paleozoic tectonic evolution of the Xing’an Mongolian Orogenic Belt.

Key words: ductile shear zone, Early Permian, tectonic evolution, central Inner Mongolia, the Xing’an Mongolian Orogenic Belt

中图分类号:

P583
P597

张祥信, 彭宇, 雷世和, 高永丰, 王广. 内蒙古中部苏尼特左旗地区勃勒金韧性剪切带的厘定及其地质意义[J]. 现代地质, 2017, 31(03): 433-442.

ZHANG Xiangxin, PENG Yu, LEI Shihe, GAO Yongfeng, WANG Guang. Determination of the Bolejin Ductile Shear Zone in the Sonidzuoqi Area, Central Inner Mongolia and Its Geological Significance[J]. Geoscience, 2017, 31(03): 433-442.

图/表 7

参考文献 38

[1]	许志琴, 张建新, 徐惠芬. 中国主要大陆山链韧性剪切带及动力学[M]. 北京: 地质出版社, 1997:1-294.
[2]	刘文灿, 马文璞, 王果胜. 大别山北麓梅山群中韧性剪切带变形特征及形成机制[J]. 现代地质, 1997, 11(1): 119-124.
[3]	MANCKETLOW N S. How ductile are ductile shear zone?[J]. Geology, 2004, 34(5): 345-348. DOI URL
[4]	TANG K D. Tectonic development of Paleozoic fold belts at the north margin of the Sino-Korean craton[J]. Tectonics, 1990, 9: 249-260. DOI URL
[5]	XU B, CHARVET J, CHEN Y, et al. Middle Paleozoic convergent orogenic belts in western Inner Mongolia(China): Framework, kinematics, geochronology and implications for tectonic evolution of the Central Asian Orogenic Belt[J]. Gondwana Research, 2013, 23: 1342-1364. DOI URL
[6]	XU B, ZHAO P, WANG Y Y, et al. The pre-Devonian tectonic framework of Xing’an-Mongolia orogenic belt(XMOB)in north China[J]. Journal of Asian Earth Sciences, 2015, 97: 183-196. DOI URL
[7]	徐备, 赵盼, 鲍庆中, 等兴蒙造山带前中生代构造单元划分初探[J]. 岩石学报, 2014, 30(7): 1841-1857.
[8]	邵济安. 中朝板块北缘中段地壳演化[M]. 北京: 北京大学出版社, 1991: 1-134.
[9]	HONG D W, CHANG W J, HUANG H Z, et al. The Permian alkaline granites in Central Inner Mongolia and their geodynamic significance[J]. Journal of Southeast Asian Earth Sciences, 1994, 10: 169-176. DOI URL
[10]	HONG D W, WANG S G, HAN B F et al. Post-orogenic alkaline granites from China and comparisons with anorogenic alkaline granites elsewhere[J]. Journal of Southeast Asian Earth Sciences, 1996, 13: 13-27. DOI URL
[11]	CHEN B, JAHN B M, WILDE S, et al. Two contrasting Paleozoic magmatic belts in northern Inner Mongolia, China: Petrogenesis and tectonic implications[J]. Tectonophysics, 2000, 328: 157-182. DOI URL
[12]	MIAO L C, FAN W M, LIU D Y, et al. Geochronology and geochemistry of the Hegenshan ophiolitic complex: Implications for late-stage tectonic evolution of the Inner Mongolia-Daxinganling orogenic belt, China[J]. Journal of Asian Earth Sciences, 2008, 32: 348-370. DOI URL
[13]	XIAO W J, WINDLEY B, HUANG B C, et al. End-Permian to mid-Triassic termination of the accretionary processes of the southern Altaids: Implications for the geodynamic evolution, Phanerozoic continental growth and metallogeny of Central Asia[J]. International Journal of Earth Sciences, 2009, 98: 1189-1217. DOI URL
[14]	JIAN P, LIU D Y, KRÖNER A, et al. Evolution of a Permian intraoceanic arc-trench system in the Solonker suture zone, Central Asian Orogenic Belt, China and Mongolia[J]. Lithos, 2010, 118: 169-190. DOI URL
[15]	李可, 张志诚, 冯志硕, 等. 内蒙古中部巴彦乌拉地区晚石炭世—早二叠世火山岩锆石SHRIMP U-Pb定年及其地质意义[J]. 岩石学报, 2014, 30(7): 2041-2054.
[16]	陈军林, 何雨栗, 杨国林, 等. 内蒙古苏左旗北部晚二叠世花岗岩地球化学特征及意义[J]. 高校地质学报, 2014, 20(1): 68-80.
[17]	TONG Y, JAHN B M, WANG T, et al. Permian alkaline grani-tes in the Erenhot-Hegenshan belt, northern Inner Mongolia, China: Model of generation, time of emplacement and regional tectonic significance[J]. Journal of Asian Earth Sciences, 2015, 97: 320-336. DOI URL
[18]	ZHANG X H, ZHANG H F, TANG Y J, et al. Geochemistry of Permian bimodal volcanic rocks from central Inner Mongolia, North China: Implication for tectonic setting and Phanerozoic continental growth in Central Asian Orogenic Belt[J]. Chemical Geology, 2008, 249: 262-281. DOI URL
[19]	ZHANG X H, YUAN L L, XUE F H, et al. Early Permian A-type granites from central Inner Mongolia, North China: Magmatic tracer of post-collisional tectonics and oceanic crustal recycling[J]. Gondwana Research, 2015, 28: 311-327. DOI URL
[20]	吴玉, 陈正乐, 陈柏林, 等. 阿尔金北缘脆-韧性剪切带内变形闪长岩的年代学、地球化学特征及其对北阿尔金早古生代构造演化的指示[J]. 岩石学报, 2016, 32(2): 555-570.
[21]	高德臻, 徐有华. 内蒙古苏尼特左旗韧性剪切带研究[J]. 地质与勘探, 2000, 26(5): 31-35.
[22]	袁士松, 葛良胜, 郭晓东, 等. 内蒙古苏尼特左旗地区韧性剪切带及其控矿作用研究——以巴彦温都尔金矿为例[J]. 西北地质, 2009, 42(4): 11-21.
[23]	徐桓, 陈天红, 龚全德, 等. 内蒙古苏尼特左旗地区韧性剪切带与金矿的关系[J]. 矿物岩石, 2014, 34(2): 68-76.
[24]	XIAO W J, WINDLEY B F, HAO J, et al. Accretion leading to collision and the Solonker suture, Inner Mongolia, China: Termination of the Central Asian Orogenic Belt[J]. Tectonics, 2003, 22(6): 1069-1088.
[25]	余学中, 薛春纪, 丛丽娟, 等. 二连浩特一带境内外构造-成矿带的衔接问题浅析[J]. 地学前缘, 2011, 18(2): 231-241.
[26]	LIU Y S, HU Z C, GAO S, et al. In situ analysis of major and trace elements of anhydrous minerals by LA-ICP-MS without applying an internal standard[J]. Chemical Geology, 2008, 257: 34-43. DOI URL
[27]	LIU Y S, HU Z C, ZONG K Q, et al. Reappraisement and refinement of zircon U-Pb isotope and trace element analyses by LA-ICP-MS[J]. Chinese Science Bulletin, 2010, 55(15): 1535-1546. DOI URL
[28]	ANDERSEN T. Correction of common Pb in U-Pb analyses that do not report ²⁰⁴Pb[J]. Chemical Geology, 2002, 192: 59-79. DOI URL
[29]	LUDWING K R. Isoplot/Ex version 3.00—A Geochronology Toolkit for Microsoft Excel[M]. Berkeley: Berkeley Geochronology Center Special Publication, 2003, 4: 1-70.
[30]	BELOUSOVA E A, GRIFFIN W L, O’REILLY S Y, et al. Igneous zircon: Trace element composition as an indicator of source rock type[J]. Contributions to Mineralogy and Petrology, 2002, 143: 602-622. DOI URL
[31]	吴元保, 郑永飞. 锆石成因矿物学研究及其对U-Pb年龄解释的制约[J]. 科学通报, 2004, 49(16): 1589-1604.
[32]	田树刚, 李子舜, 张永生, 等. 内蒙东部及邻区晚石炭世—二叠纪构造古地理环境及演变[J]. 地质学报, 2016, 90(4): 688-707.
[33]	洪大卫, 黄怀曾, 肖宜君, 等. 内蒙古中部二叠纪碱性花岗岩及其地球动力学意义[J]. 地质学报, 1994, 68(3): 219-230.
[34]	周志广, 谷永昌, 柳长峰, 等. 内蒙古东乌珠穆沁旗满都胡宝拉格地区早—中二叠世华夏植物群的发现及地质意义[J]. 地质通报, 2010, 29(1): 21-25.
[35]	FU D, HUANG B, PENG S B, et al. Geochronology and geochemistry of late Carboniferous volcanic rocks from northern Inner Mongolia, North China: Petrogenesis and tectonic implications[J]. Gondwana Research, 2016, 36: 545-560. DOI URL
[36]	李朋武, 张世红, 高锐, 等. 内蒙古中部晚石炭世—早二叠世古地磁新数据及其地质意义[J]. 吉林大学学报(地球科学版), 2012, 42(S1): 423-440.
[37]	ZHAO P, CHEN Y, XU B, et al. Did the Paleo-Asian Ocean between North China Block and Mongolia Block exist during the Late Paleozoic? First paleomagnetic evidence from central-eastern Inner Mongolia, China[J]. Journal of Geophysical Research: Solid Earth, 2013, 118: 1873-1894. DOI URL
[38]	ROLLAND Y, ALEXEIEV D V, ALFRED K, et al. Late Palaeozoic to Mesozoic kinematic history of the Talas-Ferghana strike-slip fault (Kyrgyz West Tianshan) as revealed by ⁴⁰Ar/³⁹Ar dating of syn-kinematic white mica[J]. Journal of Asian Earth Sciences, 2013, 67/68: 76-92. DOI URL

测点号	元素含量/10^-6			Th/U	同位素比值						年龄/Ma
测点号	Pb	U	Th	Th/U	²⁰⁷Pb/ ²⁰⁶Pb	1σ	²⁰⁶Pb/ ²³⁸U	1σ	²⁰⁷Pb/ ²³⁵U	1σ	²⁰⁷Pb/ ²⁰⁶Pb	1σ	²⁰⁷Pb/ ²³⁵U	1σ	²⁰⁶Pb/ ²³⁸U	1σ
1	220	671	207	0.31	0.053 2	0.002 43	0.043 94	0.000 63	0.325 18	0.014 71	336	76	286	11	277	4
2	217	551	220	0.40	0.054 0	0.002 67	0.046 87	0.000 55	0.349 20	0.016 75	372	114	304	13	295	3
3	242	670	375	0.56	0.055 5	0.002 29	0.043 12	0.000 58	0.332 28	0.013 62	432	67	291	10	272	4
4	595	1 144	173	0.15	0.052 4	0.003 27	0.046 98	0.000 56	0.339 12	0.020 81	301	145	297	16	296	3
5	304	699	477	0.68	0.055 1	0.002 15	0.045 16	0.000 58	0.346 82	0.013 24	414	62	302	10	285	4
6	137	200	148	0.74	0.054 0	0.004 47	0.045 47	0.001 11	0.340 07	0.026 46	372	131	297	20	287	7
7	274	374	229	0.61	0.067 8	0.003 64	0.050 86	0.000 79	0.475 80	0.024 12	862	79	395	17	320	5
8	1 061	1 139	978	0.86	0.061 1	0.006 14	0.044 60	0.000 79	0.375 86	0.037 15	644	224	324	27	281	5
9	182	390	109	0.28	0.055 0	0.002 53	0.052 10	0.000 59	0.398 86	0.018 13	414	81	341	13	327	4
10	419	378	253	0.67	0.054 8	0.006 12	0.049 23	0.000 82	0.372 16	0.041 05	405	254	321	30	310	5
11	157	594	59	0.10	0.053 0	0.002 28	0.046 91	0.000 56	0.342 91	0.014 15	330	100	299	11	296	3
12	141	281	217	0.77	0.052 3	0.005 60	0.043 01	0.000 79	0.310 36	0.032 69	300	245	274	25	271	5
13	296	862	138	0.16	0.054 2	0.002 16	0.049 42	0.000 50	0.369 57	0.014 23	381	92	319	11	311	3
14	118	184	142	0.77	0.063 1	0.004 24	0.047 53	0.001 02	0.412 78	0.027 50	710	105	351	20	299	6
15	214	419	314	0.75	0.051 5	0.002 52	0.047 85	0.000 81	0.342 50	0.017 01	263	83	299	13	301	5
16	286	831	200	0.24	0.061 2	0.002 40	0.044 89	0.000 50	0.382 35	0.014 61	647	63	329	11	283	3
17	154	233	203	0.88	0.059 9	0.003 44	0.046 52	0.000 81	0.380 37	0.020 34	598	86	327	15	293	5
18	204	445	66	0.15	0.055 0	0.002 23	0.055 80	0.000 67	0.427 24	0.017 66	412	71	361	13	350	4

测点号	元素含量/10^-6			Th/U	同位素比值						年龄/Ma
测点号	Pb	U	Th	Th/U	²⁰⁷Pb/ ²⁰⁶Pb	1σ	²⁰⁶Pb/ ²³⁸U	1σ	²⁰⁷Pb/ ²³⁵U	1σ	²⁰⁷Pb/ ²⁰⁶Pb	1σ	²⁰⁷Pb/ ²³⁵U	1σ	²⁰⁶Pb/ ²³⁸U	1σ
1	220	671	207	0.31	0.053 2	0.002 43	0.043 94	0.000 63	0.325 18	0.014 71	336	76	286	11	277	4
2	217	551	220	0.40	0.054 0	0.002 67	0.046 87	0.000 55	0.349 20	0.016 75	372	114	304	13	295	3
3	242	670	375	0.56	0.055 5	0.002 29	0.043 12	0.000 58	0.332 28	0.013 62	432	67	291	10	272	4
4	595	1 144	173	0.15	0.052 4	0.003 27	0.046 98	0.000 56	0.339 12	0.020 81	301	145	297	16	296	3
5	304	699	477	0.68	0.055 1	0.002 15	0.045 16	0.000 58	0.346 82	0.013 24	414	62	302	10	285	4
6	137	200	148	0.74	0.054 0	0.004 47	0.045 47	0.001 11	0.340 07	0.026 46	372	131	297	20	287	7
7	274	374	229	0.61	0.067 8	0.003 64	0.050 86	0.000 79	0.475 80	0.024 12	862	79	395	17	320	5
8	1 061	1 139	978	0.86	0.061 1	0.006 14	0.044 60	0.000 79	0.375 86	0.037 15	644	224	324	27	281	5
9	182	390	109	0.28	0.055 0	0.002 53	0.052 10	0.000 59	0.398 86	0.018 13	414	81	341	13	327	4
10	419	378	253	0.67	0.054 8	0.006 12	0.049 23	0.000 82	0.372 16	0.041 05	405	254	321	30	310	5
11	157	594	59	0.10	0.053 0	0.002 28	0.046 91	0.000 56	0.342 91	0.014 15	330	100	299	11	296	3
12	141	281	217	0.77	0.052 3	0.005 60	0.043 01	0.000 79	0.310 36	0.032 69	300	245	274	25	271	5
13	296	862	138	0.16	0.054 2	0.002 16	0.049 42	0.000 50	0.369 57	0.014 23	381	92	319	11	311	3
14	118	184	142	0.77	0.063 1	0.004 24	0.047 53	0.001 02	0.412 78	0.027 50	710	105	351	20	299	6
15	214	419	314	0.75	0.051 5	0.002 52	0.047 85	0.000 81	0.342 50	0.017 01	263	83	299	13	301	5
16	286	831	200	0.24	0.061 2	0.002 40	0.044 89	0.000 50	0.382 35	0.014 61	647	63	329	11	283	3
17	154	233	203	0.88	0.059 9	0.003 44	0.046 52	0.000 81	0.380 37	0.020 34	598	86	327	15	293	5
18	204	445	66	0.15	0.055 0	0.002 23	0.055 80	0.000 67	0.427 24	0.017 66	412	71	361	13	350	4