Quaternary magnetic stratigraphy and its sedimentary response to new tectonic movement in Shahe depression, plain area of Beijing
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摘要: 北京地区在古近—新近纪时呈"两隆一凹"的构造格局。由于南口—孙河断裂北段第四纪以来的强烈活动,在上述格局上分化出新的第四纪凹陷盆地——沙河凹陷。本次工作在沙河凹陷内开展了钻孔ZK3的第四纪磁性地层研究,结合14C同位素测年结果获得钻孔剖面早更新世、中更新世、晚更新世和全新世地层底板埋深分别为493.8m、157.4m、87.7m和7.2m,建立了钻孔剖面的第四纪地层序列。通过计算ZK3钻孔剖面第四系沉积速率分别为0.19mm/a、0.11mm/a、0.70mm/a和0.63mm/a。对比分析控盆断裂南口—孙河断裂的活动规律及北京西山的隆升特点,第四纪以来,受到北京西山隆升的影响,控制沙河凹陷的同生断裂南口—孙河断裂强烈活动,并控制了沙河凹陷的演化形成。钻孔地层平均沉积速率所体现的变化规律与山体隆升速率及断裂活动速率具有较好的响应关系。Abstract: The tectonic pattern of Beijing area in Tertiary was"two uplifts and one depression". Due to the strong activity of the north part of Sunhe fault since the Quaternary period, new Quaternary depression basin, i.e., Shahe depression, was separated from the above pattern. The authors conducted research on Quaternary magnetic stratigraphy of drill hole ZK3 in Shahe depression. In combination with the 14C isotopic dating results, the authors obtained the depth of the bottom of the strata in early Pleistocene, Middle Pleistocene, late Pleistocene and Holocene, being 439.8 m, 157.4 m, 87.7 m and 7.2 m respectively. On such a basis, the authors established the Quaternary stratigraphic sequence of drill hole profile. The Quaternary deposition rates were 0.19 mm/a, 0.11 mm/a, 0.70 mm/a and 0.63 mm/a. A comparative analysis of the activity regularity of the basin- controlling fault, i.e., Nankou- Sunhe fault, and characteristics of Beijing Xishan (Western Hills) uplift shows that since the Quaternary period, influenced by Beijing Xishan uplift, the contemporaneous faults that controlled Shahe depression, i.e., Nankou Sunhe faults, activated strongly, and controlled the evolution of Shahe depression. The variation rule of average deposition rate of the strata in the drill hole, the mountain uplift rate and the fault activity rate have a good response relationship.
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Keywords:
- Shahe depression /
- magnetic stratigraphy /
- Nankou-Sunhe fault /
- activity /
- Quaternary
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1. 研究目的(Objective)
通过实施2020年四川省自然资源厅省政府性投资地质勘查项目，对沐川地区上二叠统宣威组底部泥岩中赋存的稀有、稀土、稀散元素进行调查评价，了解“三稀”元素含量与找矿前景，希望在“三稀”找矿方面取得突破性进展，为乌蒙山贫困地区脱贫提供技术服务和支撑产业规划、扶贫开发提供资源保障。
2. 研究方法(Method)
主要采用了1∶10000地质填图、1∶500矿化带剖面测量、探槽工程、钻探工程、采样与测试分析等方法，对上二叠统宣威组底部的富镓泥岩进行了初步研究。
3. 研究结果(Results)
沐川地区位于扬子陆块西缘(图 1a)，峨眉山大火成岩省中带(图 1b)。研究区位于五指山背斜核部，其核部地层为上二叠统峨眉山玄武岩(P3e)，两翼向两侧依次出露上二叠统宣威组(P3x)、三叠系(T)、侏罗系(J)等(图 1c)。镓矿层产出于峨眉山玄武岩组(P3e)顶部、宣威组(P3x)底部的紫红色铁质泥岩、灰白色铝质泥岩、浅灰绿色泥岩、灰色泥岩、浅灰绿色泥岩及深灰色炭质泥岩中，呈层状分布，层位稳定(图 1d)；找矿标志：峨眉山玄武岩组与宣威组(P3x)的平行不整合界线之上，具“成矿界面”特征，颜色上有明显的紫红色、灰白色、灰色及深灰色等，特别是具有特征的紫红色，宏观上易识别；根据地球化学图解判别显示，其成矿物质来源有可能来源于峨眉山玄武岩及峨眉山地幔柱演化末期喷发的火山灰。
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图 1 沐川地区构造位置图(a)，峨眉山玄武岩分布简图(b)，区域地质简图(c)及镓矿层产出层位示意图(d)Figure 1. Structural location map of Muchuan area(a), Simplified geological map showing distribution of the Emeishan basalts(b), Regional geological map of Muchuan area(c) and Schematic diagram of gallium ore occurrence horizon(d)采集钻孔岩心1/2切分样品，送样至自然资源部成都矿产资源监督检测中心采用电感耦合等离子体质谱仪(ICP-MS)进行测试分析，结果显示ZK01钻孔镓(Ga)平均品位104 μg/g，矿层厚度6.27 m；ZK02钻孔镓(Ga)平均品位68.1 μg/g，矿层厚度8.67 m；ZK03钻孔镓(Ga)平均品位55.3 μg/g，矿层厚度13.87 m；三个工程的镓(Ga)平均品位为75.8 μg/g，平均厚度9.60 m。可以看出，沐川地区宣威组底部的泥岩中镓(Ga)品位较高，厚度较大，达到了中国现行的Ga矿资源工业指标要求(30 μg/g)。
4. 结论(Conclusion)
经初步估算沐川地区镓(Ga)资源量可达数万吨到数十万吨，有望找到超大型镓矿床(＞2000 t) 的潜力。沐川地区峨眉山玄武岩分布面积较广，为镓的富集成矿提供了丰富的物源。经地质填图及工程取样显示，宣威组底部富镓泥岩层厚度大，分布面积广泛，镓元素含量较高，具有巨大的找矿潜力。研究宣威组底部“三稀”元素成矿特征有助于中国在战略性关键矿产找矿方面取得重大突破，对地方国民经济发展具有重要意义。
5. 基金项目(Fund support)
本文为四川省自然资源厅2020年省政府性投资地质勘查项目(DZ20 2002)和四川省自然资源厅科技项目(kj-2022-6)资助成果。
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[1] 汪良谋, 徐杰, 黄秀铭, 等. 北京凹陷构造活动性分析[J]. 中国地震, 1990, 6(2): 25-36. Wang Liangmou, Xu Jie, Huang Xiuming, et al. An analysis of the tectonic activities in Beijing down- wapped basin[J]. Earthquake Research in China, 1990, 6(2): 25- 36 (in Chinese with English abstract). [2] 安芷生, 魏兰英, 卢演俦, 等. 顺5孔的磁性地层学和早松山世的北京海侵[J]. 地球化学, 1979, (4): 343-346. An Zhisheng, Wei Lanying, Lu Yanchou, et al. Magnetostratigraphy of the core S- 5 and the transgression in the Beijing area during the early Matuyama Epoch[J]. Geochimica, 1979, (4): 343-346 (in Chinese with English abstract). [3] 李龙吟, 陈华慧. 北京怀柔HR88-1 钻孔剖面磁性地层学研究[J]. 地层学杂志, 1994, 18(1): 39-44. Li Longyin, Chen Huahui. On magnetostratigraphy of the borehole HR88-1 in Huairou area, Beijing[J]. Journal of Stratigraphy, 1994, 18(1): 39-44 (in Chinese with English abstract). [4] 刘进峰, 郭正堂, 郝青振, 等. 甘肃秦安糜子湾剖面中新世风尘堆积的磁性地层学研究[J]. 第四纪研究, 2005, 25(4): 503-509. Liu Jinfeng, Guo Zhengtang, Hao Qingzhen, et al. Magnetostratigraphy of the Miziwan Miocene eolian deposits in Qin'an County (Gansu Province) [J]. Quaternary Sciences, 2005, 25 (4): 503-509 (in Chinese with English abstract). [5] 卢海建, 王二七, 李仕虎, 等. 青藏高原东南缘构造旋转变形分析:以四川盐源盆地古地磁研究为例[J]. 中国地质, 2015, 42(5): 1188-1201. Lu Haijian, Wang Erqi, Li Shihu, et al. Rotational deformation of the southeastern margin of Tibet: A paleomagnetic study of the Yanyuan basin, Sichuan Province[J]. Geology in China, 2015, 42 (5): 1188-1201 (in Chinese with English abstract). [6] 邓成龙. 黄土高原西部-白草塬剖面L1 和S1 记录的古地磁特征[J]. 第四纪研究, 2008, 28(5): 854-865. Deng Chenglong. Paleomagnetism of the loess/paleosol couplet L1/ S1 at the Baicaoyuan section, Western Loess Plateau[J]. Quaternary Sciences, 2008, 28(5): 854-865 (in Chinese with English abstract). [7] 郑妍, 郑洪波, 邓成龙, 等. 还原成岩作用对磁性矿物的影响及古气候意义:以长江口水下三角洲岩心YD0901 沉积物为例[J]. 第四纪研究, 2012, 32(4): 652-662. Zheng Yan, Zheng Hongbo, Deng Chenglong, et al. Diagenetic alteration on magnetic minerals and the paleoclimate implications, results from core YD0901 of Yangtze subaqueous delta[J]. Quaternary Sciences, 2012, 32(4): 652- 662 (in Chinese with English abstract). [8] 乔彦松, 赵志中, 王燕, 等. 川西甘孜黄土磁性地层学研究及其古气候意义[J]. 第四纪研究, 2006, 26(2): 250-256. Qiao Yansong, Zhao Zhizhong, Wang Yan, et al. Magnetostratigraphy and its paleoclimatic significance of a loesssoil sequence from Ganzi Area, West Sichuan Plateau[J]. Quaternary Sciences, 2006, 26(2): 250- 256 (in Chinese with English abstract). [9] 朱日祥, 邓成龙, 潘永信. 泥河湾盆地磁性地层定年与早期人类演化[J]. 第四纪研究, 2007, 27(6): 922-944. Zhu Rixiang, Deng Chenglong, Pan Yongxin. Magnetochronology of the fluvio- lacustrine sequences in the Nihewan basin and its implications for early human colonization of North East Asia[J]. Quaternary Sciences, 2007, 27(6): 922- 944 (in Chinese with English abstract). [10] 邹光富,庄忠海, 潘忠习, 等. 西藏珠穆朗玛峰北坡地区三叠纪磁性地层研究[J]. 中国地质, 2006, 33(5): 988-998. Zou Guangfu, Zhuang Zhonghai, Pan Zhongxi, et al. Triassic magnetostratigraphy of the north slope of Mount Qomolangma,Tibet[J]. Geology in China, 2006, 33(5): 988- 998 (in Chinese with English abstract). [11] 王红强. 泥河湾盆地东谷坨剖面磁性特征及环境意义[J]. 第四纪研究, 2007, 27(6): 1081-1091. Wang Hongqiang. Magnetic properties of lacustrine sediments at the Donggutuo section in the Nihewan basin and their environmental significance[J]. Quaternary Sciences, 2007, 27(6): 1081-1091 (in Chinese with English abstract). [12] 王张华, 张丹, 李晓, 等. 长江三角洲晚新生代沉积物磁性特征和磁性矿物及其指示意义[J]. 中国地质, 2008, 35(4): 670-682. Wang Zhanghua, Zhang Dan, Li Xiao, et al. Magnetic properties and relevant minerals of late Cenozoic sediments in the Yangtze River delta and their implications[J]. Geology in China, 2008, 35 (4): 670-682 (in Chinese with English abstract). [13] 赵勇, 蔡向民, 王继明, 等. 北京平原顺义ZK12-2 钻孔剖面第四纪磁性地层学研究[J]. 地质学报, 2013, 87(2): 288-294. Zhao Yong, Cai Xiangmin, Wang Jiming, et al. Quaternary magnetostratigraphy of the Shunyi area in Beijing plain using ZK12-2 borehole profile[J]. Acta Geologica Sinica, 2013, 87(2): 288-294 (in Chinese with English abstract). [14] 缪卫东, 李世杰, 王润华. 长江三角洲北翼J9 孔岩心沉积特征及地层初步划分[J]. 第四纪研究, 2009, 29(1): 126-134. Miao Weidong, Li Shijie, Wang Runhua. Preliminary study on sedimentary characteristics and stratum division of J9 Core in the north wing of the Yangtze River Delta[J]. Quaternary Sciences, 2009, 29(1): 126-134 (in Chinese with English abstract). [15] 张磊, 白凌燕, 蔡向民, 等. 北京平原南口-孙河断裂南段第四纪活动性的磁性地层学研究[J]. 第四纪研究, 2014, 34(2): 1-10. Zhang Lei, Bai Lingyan, Cai Xiangmin, et al. Magnetostratigraphy study on the south segment of Nankou- Sunhe fault at Beijing plain and its implications for the fault activity during Quaternary[J]. Quaternary Sciences, 2014, 34(2): 1-10 (in Chinese with English abstract). [16] 王力波. 岩石磁化率各向异性测量及数据处理方法[J]. 中国地质科学院南京地质矿产所所刊, 1988, 9(3): 81-92. Wang Libo. Measuring anisotropy of magnetic susceptibility of rocks and data processing[J]. Bulletin of Nanjing Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences, 1988, 9(3): 81-92 (in Chinese with English abstract). [17] Kirschvink J L. The least-squares line and plane and the analysis of paleomagnetic data[J]. 1980. Geophysical Journal international, 62: 699-718.
[18] Enkin R J. Formation et deformation de I'Asie depuis la fin de I'ere primaire: les apports de I'etude paleomagnetique des formations secondaires de Chine du Sud[J]. Paris: The Ph.D Thesis of Paris University, 1990.
[19] Cogné J P. PaleoMac: A MacintoshTM application for treating paleomagnetic data and making plate reconstructions[J]. Geochemistry, Geophysics, Geosystems, 2003, 4(1), 1007, doi: 10.1029/2001GC000227.
[20] Cande S C, Kent D V. A new geomagnetic polarity time scale for the Late Cretaceous and Cenozoic[J]. Journal of Geophysical Research, 1992, 97(10): 13917-13951.
[21] 张世民, 王丹丹, 刘旭东, 等. 北京南口-孙河断裂带北段晚第四纪活动的层序地层学研究[J]. 地震地质, 2007, 29(4): 729- 743. Zhang Shimin, Wang Dandan, Liu Xudong, et al. Sequence stratigraphy study of Late Quaternary activities of Nankou-Sunhe fault in its northern segment, Beijing[J]. Seismology and Geology, 2007, 29(4): 729-743 (in Chinese with English abstract). [22] 张世民, 王丹丹, 刘旭东, 等. 北京南口-孙河断裂晚第四纪古地震事件的钻孔剖面对比与分析[J]. 中国科学(D 辑), 2008, 38 (7): 881-895. Zhang Shimin, Wang Dandan, Liu Xudong, et al. Using borehole core analysis to reveal Late Quaternary paleoearthquakes along the Nankou-Sunhe fault, Beijing[J]. Science in China (Series D), 2008, 38(7): 881-895 (in Chinese). [23] 柯柏林. 北京平原区北部孙河断裂的地热地质特征[J]. 现代地质, 2009, 23(1): 43-48. Ke Bailin. Geothemal and geological features of Sunhe fault in the northern part of Beijing plain[J]. Geoscience, 2009, 23(1): 43- 48 (in Chinese with English abstract). [24] 裴军令, 李海兵, 孙知明, 等. 汶川地震断裂带断层滑移作用 -来自高磁化率断层岩的信息[J]. 第四纪研究, 2010, 30(4): 759-767. Pei Junling, Li Haibing, Sun Zhiming, et al. Fault slip in the Wenchuan earthquake fault zone-Information from fault rocks with higher magnetic susceptibility[J]. Quaternary Sciences, 2010, 30(4): 759-767 (in Chinese with English abstract). [25] 黄秀铭, 汪良谋, 徐杰, 等. 北京地区新构造运动特征[J]. 地震地质, 1991, 13(l): 43-51. Huang Xiuming, Wang Liangmou, Xu Jie, et al. Characteristics of neotectonics movement in Beijing area[J]. Seismology and Geology. 1991, 13(l): 43-51 (in Chinese with English abstract). [26] 车兆宏. 南口-孙河断层活动性研究[J]. 地震地质, 1994, 16(2): 115-120. Che Zhaohong. Study of the activity of Nankou-Sunhe Fault[J]. Seismology and Geology, 1994, 16(2): 115-120 (in Chinese with English abstract). [27] 郭旭东, 严富华, 黄秀铭. 北京西山新构造运动的分期[J]. 现代地质, 1995, 39(1): 51-59. Guo Xudong, Yan Fuhua, Huang Xiuming. Time division of neotectonic movement in Western Mountain area, Beijing[J]. Geoscence, 1995, 39(1): 51-59 (in Chinese with English abstract). [28] 李勇, 黄润秋, Densmore A L, 等. 龙门山彭县-灌县断裂的活动构造与地表破裂[J]. 第四纪研究, 2009, 29(3): 403-415. Li Yong, Huang Runqiu, Densmore A L, et al. Active tectonics and surface rupture of the Pengxian- Guanxian fault, Longmen Mountain, Sichuan, China[J]. Quaternary Sciences, 2009, 29(3): 403-415 (in Chinese with English abstract). [29] 侯治华, 钟南才, 郝彦军, 等. 应用高密度电法探测北京南口- 孙河隐伏断裂[J]. 防灾科技学院学报, 2011, 13(4): 1-6. Hou Zhihua, Zhong Nancai, Hao Yanjun, et al. Detecting Nankou- Sunhe buried faulty by high density resistivety method[J]. Journal of Institute of Disaster Prevention, 2011, 13 (4): 1-6 (in Chinese with English abstract). [30] 王焕, 李海兵, 李天福, 等. 汶川地震断裂带结构构造、岩性特征及其与地震活动性的关系[J]. 第四纪研究, 2010, 30(4): 768- 778. Wang Huan, Li Haibing, Li Tianfu, et al. The structure, lithologic character of the Wenchuan earthquake fault and the relation to the seismic activity[J]. Quaternary Sciences, 2010, 30(4): 768- 778 (in Chinese with English abstract). [31] 董文杰, 汤懋苍. 青藏高原隆升和夷平过程的数值模型研究[J]. 中国科学(D辑), 1997, 27(1): 65-69. Dong Wenjie, Tang Maocang. Study on numerical model of Qinghai-Tibetan Plateau uplift and planation process[J]. Science in China (Series D), 1997, 27(1): 65-69 (in Chinese). [32] 程日辉, 林畅松, 崔宝琛. 沉积型式与构造控制研究进展[J]. 地质科技情报, 2000, 19(1): 11-15. Cheng Rihui, Lin Changsong, Cui Baochen. Advances in the study of the styles of seimentation and the tectonic controls[J]. Geological Science and Technology Information, 2000, 19(1): 11- 15 (in Chinese with English abstract). [33] Van Wagoner J C. Siliciclastic sequence stratigraphy in well logs, cores and outcrops: Concepts for high- resolution correlation of time and facies[J]. AAPG, Methods in Exploration Series 7, 1990, 55: 1-240.
[34] 肖国桥, 郭正堂, 陈宇坤, 等. 渤海湾西岸BZ1 钻孔的磁性地层学研究[J]. 第四纪研究, 2008, 28(5): 909-916. Xiao Guoqiao, Guo Zhengtang, Chen Yukun, et al. Magneto stratigraphy of BZ1 borehole in west coast of Bohai Bay, northern China[J]. Quaternary Sciences, 2008, 28(5): 909-916 (in Chinese with English abstract). [35] 韦一, 张克信, 季军良, 等. 青藏高原柴达木盆地新生代沉积充填速率演化及其对构造隆升的响应[J]. 地质通报, 2013, 32(1): 105-110. Wei Yi, Zhang Kexin, Ji Junliang, et al. Cenozoic sedimentation rate evolution of Qaidam Basin in the Tibetan Plateau and its response to the uplift of the plateau[J]. Geological Bulletin of China, 2013, 32(1): 105-110 (in Chinese with English abstract). [36] 徐增连, 骆满生, 张克信, 等. 青藏高原循化、临夏和贵德盆地新近纪沉积充填速率演化及其对构造隆升的响应[J]. 地质通报, 2013, 32(1): 93-104. Xu Zenglian, Luo Mansheng, Zhang Kexin, et al. Cenozoic sedimentation rate of Xunhua, Linxia and Guide basins responding to the uplift of the Tibetan Plateau[J]. Geological Bulletin of China, 2013, 32(1): 93-104 (in Chinese with English abstract). [37] 张明安,鲜本忠. 泌阳凹陷构造活动的沉积响应[J].西安石油大学学报（自然科学版）, 2004, 19(2): 9-17. Zhang Mingan, Xian Benzhong. Response of sedimentation to structural evolution in Biyang Sag[J]. Journal of Xi’an Shiyou University (Natural Science Edition), 2004, 19(2): 9- 17 (in Chinese with English abstract). [38] 张磊, 白凌燕, 蔡向民, 等. 北京南口-孙河断裂北西段综合物探剖面定位及其活动性研究[J]. 现代地质, 2014, 28(1): 1-9. Zhang Lei, Bai Lingyan, Cai Xiangmin, et al. Study on the position of north west section of Nankou-Sunhe fault in Beijing and its activity[J]. Geoscience, 2014, 28(1): 1-9 (in Chinese with English abstract). [39] 郭旭东. 北京第四纪地质导论[M]. 重庆:重庆出版社, 2007: 12. Guo Xudong. Beijing Introduction of Quaternary Geology[M]. Chongqing: Chongqing Press, 2007:12 (in Chinese with English abstract).
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