LOCATION OF TRIASSIC TECTONIC SUTURE LINE BET WEEN COLLIDED SINO-KOREAN AND YANGTZE CRATONS IN DABIE-SULU TECTONIC ZONE
-
摘要: 大别－苏鲁构造带内超高压（UHP）和高压（HP）变质岩石的分布和不同构造岩石单位间的关系表明, 三叠纪中朝与扬子克拉通碰撞及超高压和高压变质岩石形成时的古缝合线, 位于大别地块的北缘, 沿八里畈－磨子潭－晓天一线展布, 在苏鲁地区, 五莲－烟台断裂代表被强烈改造了的古缝合线的位置.大别山北部霍山县与岳西县交界地区以及舒城、桐城和潜山县交界地区UHP和HP单位岩石的大面积分布, 说明水吼－五河断裂不是UHP和HP榴辉岩相岩石的北限, 因而, 不代表缝合线位置, “南大别”与“北大别”地体的划分地质意义是不明确的.同时, 大别山北部的镁铁质及超镁铁质岩石块体群, 包括变形的方辉橄榄岩、纯橄榄岩组合及未变形的辉石岩、角闪辉石岩和辉长岩组合, 前者与榴辉岩相岩石有相同的变形变质及几何学特征, 后者是燕山期侵入体（123~130Ma）, 因此, 不是“变质蛇绿混杂岩”, 也不代表三叠纪陆－陆碰撞时期古缝合线.强调指出, 准确地鉴别三叠纪碰撞缝合线位置, 是正确理解UHP和HP岩石形成及折返动力学过程的关键.
-
关键词:
- 大别-苏鲁构造带 /
- 超高压-高压变质作用 /
- 缝合线
Abstract: The distribution of ultrahigh pressure metamorphic (U HPM) and high pressure metamorphic (HPM) rocks and the geometrical relationship between various petrotectonic units in the Dabie－Sulu tectonic zone both indicate that the suture line that occurred when the Sino－Korean and Yangtze cratons collided and when the ultrahigh pressure and high pressure metamorphic rocks were generated, are situated at the northern margin of the Dabie massif.This suture line is distributed along the Balifan－Mozitan－Xiaotian fault, and possibly linked to the Wulian－Yantai fault, the position of the suture line violently modified in the Sulu region.The large-scale distribution of the U HP and HP metamorphic rocks near the boundary between Huoshan County and Yuexi County and in the adjacent area of Shucheng, Tongcheng and Qianshan counties in the north of Dabie Mountains, indicates that the Shuihou－Wuhe fault is not the northern limit of the U HP and HP eclogitic-facies rock.Therefore, this Shuihou－Wuhe fault does not represent the position of the suture line.In addition, the geological implication of the classification of the terrane as "Southern Dabie" and "Northern Dabie" is not accurate.At the same time, The mafic and ultramafic rock mass groups include the deformed harzburgite, pure peridotite assemblage and undeformed pyroxenite, bojite and gabbro assemblage. The first type of mafic-ultramafic rock bodies contain the same deformed and metamorphic and geometrical features as the eclogitic facies rocks.The second type of mafic-ultramafic rocks are intrusive bodies in the Yanshanian period (123－130Ma).Therefore, the mafic-ultramafic rocks are not defined as the "metamorphic ophiolitic mélange", or interpreted as the suture line in the T riassic continent-continent collision period.It is emphasized that the accurate identification of the position of the T riassic collision suture line is the key to the correct understanding of the formation and reciprocal dynamic process of the U HP and HP rocks.-
Key words:
- Dabie-Sulutectoniczone /
- UHPMandHPM /
- sutureline
-
图 1 大别山岳西地区地质略图
CC.核部杂岩; UHP.超高压单位; BMXF.八里畈-磨子潭-晓天断裂带; TLF.郯城-庐江断裂带
Fig. 1. Schematic geological map of the Yuexi area in the northeastern part of the Dabie massif
图 2 大别-苏鲁构造带三叠纪碰撞后伸展构造略图
QHF.确山-合肥断裂带; XFF.信阳-肥西断裂带; GMF.龟山-梅山断裂带; JMF.军马河-马蹄湾断裂带; BMXF.八里畈-磨子潭-晓天断裂带; XGF.襄樊-广济断裂带; TLF.郯城-庐江断裂带; WYF.五莲-烟台断裂带; CC.核部杂岩; UHP.超高压单位; HP.高压单位; EB.绿帘石-蓝片岩单位; SC.沉积盖层
Fig. 2. Simplified structural map of the Dabie-Sulu region, illustrating the extensional tectonic picture that postdates the Tri-assic continental collision between the Sino-Korean and Yangtze cratons
-
[1] 李曙光, 李惠民, 陈移之, 等. 大别山-苏鲁地体超高压变质年代学——Ⅱ. 锆石U-Pb同位素体系[J]. 中国科学(D辑), 1997, 27(3): 200~206. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK199703001.htm [2] Chavagnac V, Jahn B M. Coesite-bearing eclogites from the Bixiling complex, Dabie Mountains, China: Sm-Nd ages, geochemical characteristics and tectonic implications [J]. Chemical Geology, 1996, 133: 29~51. doi: 10.1016/S0009-2541(96)00068-X [3] Hacker B R, Wang Q C. Ar/Ar geochronology of ultrahigh-pressure metamorphism in central China[J]. Tectonics, 1995, 14(4): 994~1006. doi: 10.1029/95TC00932 [4] Ames L, Zhou G Z, Xiong B C. Geochronology and geochemistry of ultrahigh-pressure metamorphism with implication for collision of the Sino-Korean and Yangtze Cratons, Central China[J]. Tectonics, 1996, 15(2): 472~489. doi: 10.1029/95TC02552 [5] Maruyama S, Tabata H, Nutman A B, et al. SHRIMP UPb geochronology of ultrahigh-pressure metamorphic rocks of the Dabie Mountains, central China[J]. Continental Dynamics, 1998, 3(1~2): 72~85. [6] Zhai M G, Cong B L, Zhao Z Y, et al. Petrologica-ltectonic units in the coesite-bearing metamorphic terrain of the Dabie Mountains, Central China and their geotectonic implications[J]. Journal of Southeast Asian Earth Sciences, 1995, 11(1): 1~13. doi: 10.1016/0743-9547(94)00036-E [7] Wang Q C, Liu X H, Maruyama S, et al. Top boundary of the Dabie UHPM rocks, Central China[J]. Journal of Southeast Asian Earth Sciences, 1995, 11(4): 295~300. doi: 10.1016/0743-9547(94)00035-D [8] 徐树桐, 江来利, 刘贻灿, 等. 大别山区(安徽部分)的构造格局和演化过程. 地质学报, 1992, 66(1): 1~15. https://www.cnki.com.cn/Article/CJFDTOTAL-DZXE199201000.htm [9] 索书田, 钟增球, 游振东. 大别地块超高压变质期后伸展变形及超高压变质岩石折返过程[J]. 中国科学(D辑), 2000, (1): 9~17. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK200001001.htm [10] 游振东, 钟增球, 张泽明. 桐柏-大别山区高压变质相的构造配置[J]. 地学前缘, 1999, 6(4): 237~245. doi: 10.3321/j.issn:1005-2321.1999.04.006 [11] 索书田. 大别地块超高压变质省的构造变形研究[J]. 地学前缘, 1999, 6(4): 255~262. doi: 10.3321/j.issn:1005-2321.1999.04.008 [12] Ree J H, Cho M, Kwon S T, et al. Possible eastward extension of Chinese collision belt in South Korea: the Imjingang belt[J]. Geology, 1996, 24 (12): 1071~1074. doi: 10.1130/0091-7613(1996)024<1071:PEEOCC>2.3.CO;2 [13] 魏春景, 单振刚, 张立飞, 等. 北大别榴辉岩的确定及其地质意义[J]. 科学通报, 1997, 42(17): 1832~1835. https://www.cnki.com.cn/Article/CJFDTOTAL-KXTB199717011.htm [14] Suo S T, Zhong Z Q. Sequence of ductile shear zone in UHP metamorphic province within Dabie massif, China [J]. Journal of China University of Geosciences, 1998, 9 (3): 189~195. [15] Tsai C H, Liou J G, Ernst W G. Eclogite facies relics and retrogressed garnet peridotite in the North Dabie complex, centra-l eastern China, and suggested implications for regional tectonics[A]. In: International Workshop on UHP Metamorphism and Exhumation[C]. Calif: Stanford Univ, 1998. A153~154. [16] Zhong Z Q, Suo S T, You Z D. Extensional tectonic framework of post high and ultrahigh pressure metamorphism in Dabieshan, China[J]. Journal of China University of Geosciences, 1998, 9(1): 1~5. [17] 葛宁洁, 侯振辉, 李惠民, 等. 大别造山带岳西沙村镁铁质- 超镁铁质岩体的锆石U -Pb年龄. 科学通报, 1999, 44(19): 2110~2113. https://www.cnki.com.cn/Article/CJFDTOTAL-KXTB200006020.htm [18] Zhang R Y, Liou J G, Tsai C H. Petrogenesis of a hightemperature metamorphic terrane: a new tectonic interpretation for the north Dabieshan, Central China[J]. J metamorphic Geol, 1996, 14(3): 319~333. [19] Hacker B R, Ratschbacher L, Webb L. U/Pb zircon ages constrain the architecture of the ultrahigh-pressure Qinling-Dabie orogen, China[J]. Earth and Planetary Science Letters, 1998, 161(1~4): 215~230. [20] Mattauer M. Intracontinental subduction, crust-mantle decollement and crusta-l stacking wedge in the Himalayas and other collision belts[A]. In: Caward M P, Ries A C, eds. Collision tectonics[C]. London: Geological Society Special Publication, 1986, 19: 37~50. [21] 刘景波, 国连杰, 吴颍. 豫南-鄂北大别山北部高压角闪石榴辉岩的研究[J]. 地质科学, 1997, 32(4): 409~422. https://www.cnki.com.cn/Article/CJFDTOTAL-DZKX704.000.htm [22] 马文璞. 大别山北麓的石炭系及其大地构造意义. 地质学报, 1991, 65(1): 17~26. https://www.cnki.com.cn/Article/CJFDTOTAL-DZXE199101001.htm [23] 张国伟, 孟庆任, 于在平, 等. 秦岭造山带的造山过程及其动力学特征[J]. 中国科学(D辑), 1996, 26(3): 193~200. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK199603000.htm [24] Meng Q R, Zhang G W. Timing of collision of the North and South China blocks: controversy and reconciliation [J]. Geology, 1999, 27(2): 123~126 -
下载:
点击查看大图
图(2)
计量
- 文章访问数: 3891
- HTML全文浏览量: 468
- PDF下载量: 17
- 被引次数: 0
