Causes and Tectonic Evolution of Bangong Lake Basin
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摘要: 依据河湖相沉积物的沉积特征、沉积年龄和分布规律, 结合ETM+构造和第四系沉积地层的遥感解译, 对班公错湖盆的成因和构造演化特征进行系统的剖析.从地形地貌、沉积建造和构造上分析, 推断班公错湖盆为构造成因的拉分断陷湖盆.根据湖盆周边的断层活动特征和湖盆的沉积响应, 将班公错湖盆的演化分为4个阶段, 依次为湖盆打开的幼年期(晚于早中新世)、湖盆扩展的青年期(早于8.1±1Ma)、湖盆急剧扩展伴随湖盆中心南移的壮年期(晚于0.94Ma)和湖盆不对称萎缩的老年期(晚于0.23Ma).Abstract: Causes and tectonic evolution of Bangong lake basin are studied based on the results of geological survey, fluvial sedimentary natures, the age of deposition and its distribution law, referring to ETM+ remote sensing interpretation about tectonics and Quaternary sedimentary strata. Analysis of topography, sedimentary and tectonics indicates that Bangong lake basin is a pull-apart faulted basin; according to activity characteristics of the faults around the lake basin and sedimentary response, the evolution of lake basin is devided into four stages: infancy of lake basin open (later than the early Miocene), adolescence of basin expansion (8.1±1Ma), maturity of rapid expansion of the lake basin with lake basin center moving south (later than 0.94Ma) and gerontic age of lake basin asymmetric atrophy (later than 0.23Ma).
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Key words:
- Qinghai-Tibet plateau /
- Bangong lake /
- causes of lake basin /
- evolution of lake basin /
- tectonics
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图 1 青藏高原西缘构造简图
Fig. 1. Generalized structural map of the west margin of the Tibetan plateau
图 2 班公错湖盆周边线性构造遥感解译(遥感数据为时相为2006年9月23日空间分辨率15m的ETM+)
Fig. 2. Remote sensing interpretation image showin linear structure in the surrounding area of Bangong lake (the remote sensing data(ETM+) index: time is September 23, 2006, spatial resolution is 15m)
图 3 湖盆周边断层发育类型
a.湖盆南侧NW向右行走滑断层(镜向340°)；b.湖盆北岸近EW向正断层(镜向10°)；c.乌奖西NE向正断层(镜向310°)；d.日土西近EW向逆断层(镜向260°)
Fig. 3. Accumulation types of faults surrounding area of Bangong lake in the study area
图 4 班公错周边地区晚新生代沉积地层遥感解译(遥感数据为时相为2006年9月23日空间分辨率15m的ETM+)
Fig. 4. Remote sensing interpretation image showing Late Cenozoic sedimentary strata in the surrounding area of Bangong lake (the remote sensing data(ETM+) index: time is September 23, 2006, spatial resolution is 15m)
图 5 班公错南北两侧湖相阶地剖面
Fig. 5. Profiles of both the north Bangong lake lacustrine terraces and the south ones
图 6 班公错湖盆演化示意
虚线为早期湖盆边界，实线为当前湖盆边界
Fig. 6. Schematic diagram of the evolution of Bangong lake basin
表 1 砾岩胶结物ESR测年数据
Table 1. ESR dating data of conglomerate cements
样品编号 古剂量(Gy) 年剂量(mGy) 年龄(Ma) DP685-1砾岩中碳酸钙 799.9 2.206 36.3±3.6 DP685-2砾岩中碳酸钙 2300.0 3.164 94.0±9.0 DP721-1亚砂土中碳酸钙 989.5 4.154 23.8±2.3 DP721-2砾岩中碳酸钙 1320.5 3.898 33.9±4.0 DP721-3砾岩中碳酸钙 3021.1 3.872 78.0±8.0 
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表 2 断层面石英热活化ESR测年数据
Table 2. ESR dating data of quartz on fault plane
样品编号 顺磁中心浓度(1015Sp/g) 铀当量含量(μg/g) 年龄(Ma) S3323-2石英 0.031 0.929 6.7±6.0 S2616-1石英 0.083 2.048 8.1±1.0
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表 3 班公错南北两侧阶地分布和沉积特征对比
Table 3. Comparison of both the north Bangong lake lacustrine terraces and the south ones distribution and sedimentary characteristics
剖面号 阶地级数 阶地类型 沉积特征 拔湖高度(m) 测年数据 NPM685 Ⅰ级 内叠阶地 二元结构，底部为一套细粒砾石层，砾石成分以砂岩和灰岩为主，顶部为一厚度35.1cm的粘土层. 3.27 Ⅱ级 基座阶地 砾石层为主，砾径由底到顶变粗，砾石成分以灰岩为主，少量板岩、砂岩和脉石英，磨圆次圆，无定向，中间夹有两层厚度5~8cm的粘土层. 14.03 Ⅲ级 基座阶地 基座剥露地表为一套砂板岩夹灰岩，阶地堆积层为一大套巨厚砾石层，砾石磨圆度较好呈圆-次圆，胶结呈半固结-固结状态，砾石砾径整体偏大，集中在5~15cm，定向性比较差. 84.10 36.3±3.6万年(69m)ESR 94.0±9.0万年(84m)ESR NPM721 Ⅰ级 内叠阶地 二元结构特征明显，底部为一套细粒砾石层，松散，砾石成分以灰岩和砂岩为主，磨圆中等，中间层为一套厚度21.5cm的灰黄色亚粘土层，并见有植物根系，顶层为一套厚度16.4cm的灰白色粘土层，含有细砂透镜体，见有较大量的植物根系. 21.95 Ⅱ级 未见底 可见部分大概可以分为4层，由底部到顶部依次为：15.3cm的灰色砾石层、9.5cm的灰白色粘土层、14.6cm的灰色细砂层、17.6cm的松散细粒砾石层和45.0cm的松散中粗粒砾石层. 23.65 Ⅲ级 基座阶地 主体为一套砾石层，细砂粘土胶结，底部为一套磨圆分选相对较好的细粒砾石层，砾石略有定向，扁平面的产状为195°∠23°，中间砾径逐渐增大，发育一套厚度13.6cm的巨砾砾石层，该层砾石砾径主要集中在8~15cm，向顶部砾石砾径逐渐降低，最顶部为一套厚度45cm中粗粒砾石层-细粒砾石层-粘土层的粒序沉积. 65.91 23.8±2.3万年(ESR) Ⅳ级 基座阶地 由底部到顶部砾石砾径由粗到细的灰褐色砾石层，亚砂土和粘土胶结，砾石磨圆呈次圆，砾径集中在3~8cm，胶结呈半固结状态，最顶层砾石含量有所降低，不足50%. 78.28 33.9±4.0万年(ESR) Ⅴ级 基座阶地 主体为一套厚层灰褐色砾石层，砾石砾径80%集中在3~5cm，少数超过10cm，胶结呈半固结状态，分选磨圆较好，砾石成分以灰岩为主，偶见砂岩和脉石英等. 93.74 78.0±8.0万年(ESR) SPM461 Ⅰ级 内叠阶地 二元结构，砾石层与粘土层互层，底部为一套砾石层，中间夹有两层厚度15cm左右的粘土层，顶部同样为一套砾石层，砾石层中充填有细砂和粘土，磨圆中等. 4.90 Ⅱ级 内叠阶地 主体为一套砾石层，砾石层中砾石成分以砂岩、板岩和脉石英为主，中细粒，松散胶结，中间夹有一层厚度8.4cm的粘土层. 21.56 Ⅲ级 基座阶地 中细粒灰色砾石层，胶结松散，砾石成分95%为砂岩，少量的脉石英，磨圆呈次圆-次棱角，分选中等，定向性比较差. 23.83 SPM451 Ⅰ级 内叠阶地 二元结构，砾石层夹亚砂土层和亚砂土透镜体，底部和顶部都为一套中粗粒砾石层，砾石磨圆分选中等，扁平面定向性不明确，砾石成分以砂岩和板岩为主，偶见脉石英，局部夹有亚砂土透镜体.中间分别夹有厚度0.89m、0.12m和0.1m的三层灰黄色亚砂土层. 9.02
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Chen, Z.E., Lin, Q.Y., 1993. Significance of Neotectonic Movement of Lake Extension and Shrinkage in Qinghai-Tibet Plateau. Earthquake, 1: 31-52 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DIZN199301006.htm Chinese Academy of Sciences Qinghai-Tibetan Plateau Comprehensive Scientific Survey Team, 1984a. Rivers and lakes of Tibet. Science Press, Beijing (in Chinese). Chinese Academy of Sciences Qinghai-Tibetan Plateau Comprehensive Scientific Survey Team, 1984b. Quaternary Geology of Tibet. Science Press, Beijing (in Chinese). Dortch, J.M., Owen, L.A., Caffee, M.W., et al., 2011. Catastrophic Partial Drainage of Pangong Tso, Northern India and Tibet. Geomorphology, 125(1): 109-121. doi: 10.1016/j.geomorph.2010.08.017 Fan, H., Gasse, F., Huc, A., et al., 1996. Holocene Environmental Changes in Bangong Co Basin (Western Tibet). Part 3: Biogenic Remains. Palaeogeography, Palaeoclimatology, Palaeoecology, 120(1-2): 65-78. doi: 10.1016/0031-0182(95)00034-8 Guo, T.Y., Liang, D.Y., Zhang, Y.Z., et al., 1991. Geology of Ngari Tibet (Xizang). China University of Geosciences Press, Wuhan (in Chinese). Jason, M.D., Lewis, A.O., Marc, W.C., et al., 2011. Catastrophic Partial Drainage of Pangong Tso, Northern India and Tibet. Geomorphology, 125: 109-121. doi: 10.1016/j.geomorph.2010.08.017 Jia, Y.L., Shi, Y.F., Wang, S.M., et al., 2001. Lake-Expanding Events in the Tibetan Plateau since 40ka BP. Science in China (Series D): Earth Sciences, 44(1): 301-315. doi: 10.1007/BF02912000 Jiang, J.H., Wang, R.J., Qu, X.M., et al., 2011. Crustal Extension of the Bangong Lake Arc Zone, Western Tibetan Plateau, after the Closure of the Tethys Oceanic Basin. Earth Science—Journal of China University of Geosciences, 36(6): 1021-1032(in Chinese with English abstract). doi: 10.3799/dqkx.2011.108 Lacassin, R., Valli, F., Arnaud, N., et al., 2004. Large-Scale Geometry, Offset and Kinematic Evolution of the Karakorum Fault, Tibet. Earth and Planetary Science Letters, 219(3-4): 255-269. doi: 10.1016/S0012-821X(04)00006-8 Li, B.Y., 2000. The Last Greatest Lakes on the Xizang(Tibetan) Plateau. Acta Geographica Sinica, 55(2): 174-182(in Chinese with English abstract). Li, H.B., Franck, V., Xu, Z.Q., et al., 2006. Deformation and Tectonic Evolution of the Karakorum Fault, Western Tibet. Geology in China, 33(2): 239-255(in Chinese with English abstract). http://www.researchgate.net/publication/215868790_Deformation_and_tectonic_of_the_Karakorum_Fault_Western_Tibet Matte, P., Tapponnier, P., Arnaud, N., et al., 1996. Tectonics of Western Tibet, between the Tarim and the Indus. Earth and Planetary Science Letters, 142(3-4): 311-330. doi: 10.1016/0012-821X(96)00086-6 Murphy, M.A., Yin, A., Kapp, P., et al., 2000. Southward Propagation of the Karakoram Fault System, Southwest Tibet: Timing and Magnitude of Slip. Geology, 28(5): 451-454. doi: 10.1130/0091-7613(2000)28<451:SPOTKF>2.0.CO;2 Phillips, R.J., Parrish, R.R., Searle, M.P., 2004. Age Constraints on Ductile Deformation and Long-Term Slip Rates along the Karakoram Fault Zone, Ladakh. Earth and Planetary Science Letters, 226(3): 305-319. doi: 10.1016/j.epsl.2004.07.037 Rahe, B., Ferrill, D.A., Morris, A.P., 1998. Physical Analog Modeling of Pull-Apart Basin Evolution. Tectonophysics, 285(1-2): 21-40. doi: 10.1016/S0040-1951(97)00193-5 Reneau, S.L., 2000. Stream Incision and Terrace Development in Frijoles Canyon, Bandelier National Monument, New Mexico, and the Influence of Lithology and Climate. Geomorphology, 32(1-2): 171-193. doi:10.1016/S0169- 555X_99.00094-X Searle, M.P., Phillips, R.J., 2007. Relationships between Right-Lateral Shear along the Karakoram Fault and Metamorphism, Magmatism, Exhumation and Uplift: Evidence from the K2-Gasherbrum-Pangong Ranges, North Pakistan and Ladakh. Journal of the Geological Society, 164(2): 439-450. doi: 10.1144/0016-76492006-072 Shi, Y.F., Li, J.J., Li, B.Y., et al., 1999. Uplift of the Qinghai-Tibet Plateau and East Asia Environmental Change during Late Cenozoic. Acta Geographica Sinica, 54(1): 10-21(in Chinese with English abstract). http://www.researchgate.net/publication/283826647_Uplift_of_the_Qinghai-Xizang_Tibetan_Plateau_and_east_asia_environmental_change_during_Late_Cenozoic Sun, J.L., Zhang, Y.F., Xu, H.L., et al., 2011. Cenozoic Tectonics and Basin Evolution in the Southwestern Nansha Sea Area. Earth Science—Journal of China University of Geosciences, 35(5): 956-966(in Chinese with English abstract). doi: 10.3799/dqkx.2011.101 Van Campo, E., Cour, P., Hang, S., 1996. Holocene Environmental Changes in Bangong Co Basin (Western Tibet). Part 2: The Pollen Record. Palaeogeography, Palaeoclimatology, Palaeoecology, 120(1-2): 49-63. doi: 10.1016/0031-0182(95)00033-X Zheng, M.P., Liu, W.G., Xiang, J., et al., 1983. On Saline Lakes in Tibet, China. Acta Geologica Sinica, 2: 184-194 (in Chinese with English abstract). Zhu, D.G., Meng, X.G., Zhao, X.T., et al., 2001. Nam Tso Lacustrine Sediments and the Ancient Big Lake in Northern Tibet Plateau. Acta Geoscientia Sinica, 22(1): 149-155(in Chinese with English abstract). http://www.oalib.com/paper/1558073 Zhu, D.G., Zhao, X.T., Meng, X.G., et al., 2001. On the Quaternary Lacustrine Deposits and the Lacustrine Landform of Nam Co, Xizang (Tibet). Journal of Jilin University (Earth Science Edition), 33(2): 156-162(in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-CCDZ200302009.htm 陈兆恩, 林秋燕, 1993. 青藏高原湖泊涨缩的新构造运动意义. 地震, 1: 31-52. https://www.cnki.com.cn/Article/CJFDTOTAL-DIZN199301006.htm 郭铁鹰, 粱定益, 张宜智, 等, 1991. 西藏阿里地质. 武汉: 中国地质大学出版社. 江军华, 王瑞江, 曲晓明, 等, 2011. 青藏高原西部班公湖岛弧带特提斯洋盆闭合后的地壳伸展作用. 地球科学——中国地质大学学报, 36(6): 1021-1032. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX201106008.htm 李炳元, 2000. 青藏高原大湖期. 地理学报, 55(2): 174-182. doi: 10.3321/j.issn:0375-5444.2000.02.005 李海兵, Franck Valli, 许志琴, 等, 2006. 喀喇昆仑断裂的变形特征及构造演化. 中国地质, 33(2): 239-255. doi: 10.3969/j.issn.1000-3657.2006.02.002 施雅风, 李吉均, 李炳元, 等, 1999. 晚新生代青藏高原的隆升与东亚环境变化. 地理学报, 54(1): 10-21. doi: 10.3321/j.issn:0375-5444.1999.01.002 孙金龙, 张云帆, 徐辉龙, 等, 2011. 南沙西南海域新生代构造活动特征与盆地演化. 地球科学——中国地质大学学报, 36(5): 956-966. https://www.cnki.com.cn/Article/CJFDTOTAL-DQKX201105025.htm 郑绵平, 刘文高, 向军, 等, 1983. 论西藏的盐湖. 地质学报, (2): 184-194. https://www.cnki.com.cn/Article/CJFDTOTAL-DZXE198302007.htm 中国科学院青藏高原综合科学考察队, 1984a. 西藏河流与湖泊. 北京: 科学出版社. 中国科学院青藏高原综合科学考察队, 1984b. 西藏第四纪地质. 北京: 科学出版社. 朱大岗, 孟宪刚, 赵希涛, 等, 2001. 纳木错湖相沉积与藏北高原古大湖. 地球学报, 22(2): 149-155. doi: 10.3321/j.issn:1006-3021.2001.02.011 朱大岗, 赵希涛, 孟宪刚, 等, 2003. 西藏纳木错第四纪湖泊沉积与湖成地貌——兼论藏北高原古大湖问题. 吉林大学学报(地球科学版), 33(2): 156-162. https://www.cnki.com.cn/Article/CJFDTOTAL-CCDZ200302009.htm -
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