岷江上游叠溪混杂堆积体的沉积特征及其成因分析
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摘要
青藏高原东缘岷江上游叠溪河谷段在地质历史时期发生了一次大规模滑坡堵江事件,形成一个特大型堰塞湖。堰塞湖形成后在晚更新世晚期(约27 ka B.P.)发生了溃决,并在坝体下游形成长约5 km的天然混杂堆积体,判断其为叠溪古滑坡堰塞湖溃决后形成的溃坝堆积。该套溃坝堆积体具有叠瓦构造、孔洞构造、块状构造、杂基构造、支撑—叠置构造及韵律互层构造。从上游至下游,溃坝堆积体的出露厚度逐渐变薄,砾石碎屑成分表现出由粗变细的变化趋势。溃坝堆积体是由高流态灾难性洪流及常态流和河流态两种机制形成,相应地具有两大类沉积相:巨砾层相及砾石层相和砂层相,依据溃坝堆积的地貌结构和沉积相特征可以推断叠溪古滑坡堰塞湖至少发生过一次极其罕见的灾难性溃决洪水事件。
A distinct landslide damming incident occurred during a prehistoric period in the upper Minjiang River at the southeastern margin of the Tibetan Plateau. This formed a very large dammed lake which breached and caused a large outburst flood at about 27 ka. Between the section of the ancient dam and its downstream areas( 5 km),an abundance of diamicts have been observed for the first time. We determine that they are outburst deposits induced by breaching of the Diexi paleolandslide-dammed lake. The sedimentary structures of the outburst deposits include imbricates,cavitation,matrix and massive structures,gravel support-stacked,as well as rhythmitic interbedded structures,among others. From upstream to downstream,the thickness of the outburst deposits gradually thins,and the gravel shows a tendency to change from coarse to fine. Hyperconcentrated flood flows and normal stream or fluctuating flows are recorded,indicating contrasting regimes of sediment transport. Also,two kinds of sedimentary facies occur in the outburst deposits: boulder facies,and gravel and sand facies. From the way in which the sedimentary facies developed,at least one catastrophic outburst flood event can be assumed to have occurred in the Diexi paleodammed lake.
A distinct landslide damming incident occurred during a prehistoric period in the upper Minjiang River at the southeastern margin of the Tibetan Plateau. This formed a very large dammed lake which breached and caused a large outburst flood at about 27 ka. Between the section of the ancient dam and its downstream areas( 5 km),an abundance of diamicts have been observed for the first time. We determine that they are outburst deposits induced by breaching of the Diexi paleolandslide-dammed lake. The sedimentary structures of the outburst deposits include imbricates,cavitation,matrix and massive structures,gravel support-stacked,as well as rhythmitic interbedded structures,among others. From upstream to downstream,the thickness of the outburst deposits gradually thins,and the gravel shows a tendency to change from coarse to fine. Hyperconcentrated flood flows and normal stream or fluctuating flows are recorded,indicating contrasting regimes of sediment transport. Also,two kinds of sedimentary facies occur in the outburst deposits: boulder facies,and gravel and sand facies. From the way in which the sedimentary facies developed,at least one catastrophic outburst flood event can be assumed to have occurred in the Diexi paleodammed lake.
引文
[1] Evans S G. The maximum discharge of outburst floods caused by the breaching of man-made and natural dams[J]. Canadian Geotechnical Journal,1986,23(3):385-387.
[2] Costa J E,Schuster R L. The formation and failure of natural dams[J]. GSA Bulletin,1988,100(7):1054-1068.
[3] Dai F C,Lee C F,Deng J H,et al. The 1786 earthquake-triggered landslide dam and subsequent dam-break flood on the Dadu River,Southwestern China[J]. Geomorphology,2005,65(3/4):205-221.
[4] Chen J,Dai F C,Lv T Y,et al. Holocene landslide-dammed lake deposits in the Upper Jinsha River,SE Tibetan Plateau and their ages[J]. Quaternary International,2013,298:107-113.
[5] Wang P F,Chen J,Dai F C,et al. Chronology of relict lake deposits around the Suwalong paleolandslide in the upper Jinsha River,SE Tibetan Plateau:implications to Holocene tectonic perturbations[J]. Geomorphology,2014,217:193-203.
[6]崔之久,张梅,崔鹏,等.初论堰塞湖溃坝沉积相特征[J].山地学报,2015,33(2):129-140.[Cui Zhijiu,Zhang Mei,Cui Peng,et al. Discussion on characteristics of sedimentary facies of dammedlakes outburst deposits[J]. Mountain Research,2015,33(2):129-140.]
[7] Wassmer P,Schneider J L,Pollet N,et al. Effects of the internal structure of a rock-avalanche dam on the drainage mechanism of its impoundment,Flims sturzstrom and Ilanz paleo-lake,Swiss Alps[J]. Geomorphology,2004,61(1/2):3-17.
[8] Krivonogov S K,Sheinkman V S,Mistruykov A A. Stages in the development of the Darhad dammed lake(Northern Mongolia)during the Late Pleistocene and Holocene[J]. Quaternary International,2005,136(1):83-94.
[9] Moreiras S M. Chronology of a probable neotectonic Pleistocene rock avalanche,Cordon del Plata(Central Andes),Mendoza,Argentina[J]. Quaternary International,2006,148(1):138-148.
[10]崔之久,葛道凯,关保德,等.混杂堆积与环境[M].石家庄:河北科学技术出版社,2013:1-718.[Cui Zhijiu,Ge Daokai,Guan Baode,et al. Diamicton and environment[M]. Shijiazhuang:Hebei Science and Technology Press,2013:1-718.]
[11]陈剑,崔之久.金沙江上游雪隆囊古滑坡堰塞湖溃坝堆积体的发现及其环境与灾害意义[J].沉积学报,2015,33(2):275-284.[Chen Jian,Cui Zhijiu. Discovery of outburst deposits induced by the Xuelongnang paleolandslide-dammed lake in the upper Jinsha River,China and its environmental and hazard significance[J]. Acta Sedimentologica Sinica,2015,33(2):275-284.]
[12] Zakaria A A,Johnson H D,Jackson C A L,et al. Sedimentary facies analysis and depositional model of the Palaeogene West Crocker submarine fan system,NW Borneo[J]. Journal of Asian Earth Sciences,2013,76:283-300.
[13]刘艳蕊,杨一博,方小敏,等.沉积相变迁对内陆湖泊沉积易溶盐作为古环境指标的影响:以西宁盆地为例[J].沉积学报,2014,32(1):101-109.[Liu Yanrui,Yang Yibo,Fang Xiaomin,et al. Control of sedimentary facies alternation on water soluble salts in inland lake sediments as a paleoenvironmental proxy:A case study from Xining Basin[J]. Acta Sedimentologica Sinica,2014,32(1):101-109.]
[14] Wilson R D,Schieber J. Sedimentary facies and depositional environment of the middle Devonian Geneseo formation of New York,U.S. A.[J]. Journal of Sedimentary Research,2015,85(11):1393-1415.
[15]郭岭,贾超超,朱毓,等.现代渭河西安段沉积体沉积相与岩相特征[J].沉积学报,2015,33(3):543-550.[Guo Ling,Jia Chaochao,Zhu Yu,et al. Characteristics of sedimentary facies and lithofacies of modern Weihe River in Xi’an[J]. Acta Sedimentologica Sinica,2015,33(3):543-550.]
[16] Chen L Q,Guo F S,Tang C. Evolution of the Late Cretaceous Yongfeng-Chongren Basin in Jiangxi Province,southeast China:insights from sedimentary facies analysis and pebble counting[J].Journal of Mountain Science,2016,13(2):342-351.
[17] Khawfany A A,Aref M A,Taj R J. Human-induced changes in sedimentary facies and depositional environments, Sarum area,Red Sea coast,Saudi Arabia[J]. Environmental Earth Sciences,2017,76:61.
[18]邓世彪,关平,张鹏飞.东营凹陷青南地区沙四上亚段物源沉积体系与滩坝分布[J].沉积学报,2017,35(3):561-576.[Deng Shibiao,Guan Ping,Zhang Pengfei. Provenance,sedimentary system and beach bar distribution of the Upper Es4in Qingnan area,Dongying Depression[J]. Acta Sedimentologica Sinica,2017,35(3):561-576.]
[19] Ma J X,Chen J,Cui Z J,et al. Sedimentary evidence of outburst deposits induced by the Diexi paleolandslide-dammed lake of the upper Minjiang River in China[J]. Quaternary International,2018,464(Part B):460-481.
[20]张岳桥,李海龙,李建华.青藏高原东缘中更新世伸展作用及其新构造意义[J].地质评论,2010,56(6):781-791.[Zhang Yueqiao,Li Hailong,Li Jianhua. Middle Pleistocene extension along the eastern margin of Xizang(Tibetan)Plateau and its Neotectonic significance[J]. Geological Review,2010,56(6):781-791.]
[21] Kataoka K S. Geomorphic and sedimentary evidence of a gigantic outburst flood from Towada caldera after the 15 ka Towada-Hachinohe ignimbrite eruption,northeast Japan[J]. Geomorphology,2011,125(1):11-26.
[22] Russell A J,Knudsen O. An ice-contact rhythmite(turbidite)succession deposited during the November 1996 catastrophic outburst flood(j9kulhlaup),Skeiarárj9kull,Iceland[J]. Sedimentary Geology,1999,127(1/2):1-10.
[23] Carling P A. Freshwater megaflood sedimentation:what can we learn about generic processes?[J]. Earth-Science Reviews,2013,125:87-113.
[24] Walker R G. Facies models[M]. Canada:Geological Association of Canada,1982.
[25] Cutler P M,Colgan P M,Mickelson D M. Sedimentologic evidence for outburst floods from the Laurentide Ice Sheet margin in Wisconsin,USA:implications for tunnel-channel formation[J]. Quaternary International,2002,90(1):23-40.
[26] Benn D I,Owen L A,Finkel R C,et al. Pleistocene lake outburst floods and fan formation along the eastern Sierra Nevada,California:implications for the interpretation of intermontane lacustrine records[J]. Quaternary Science Reviews,2006,25(21/22):2729-2748.
[27] Smith G A. Coarse-grained nonmarine volcaniclastic sediment:terminology and depositional process[J]. GSA Bulletin,1986,97(1):1-10.
[28] Todd S P. Stream-driven,high-density gravelly traction carpets:possible deposits in the trabeg conglomerate formation,SW Ireland and some theoretical considerations of their origin[J]. Sedimentology,1989,36(4):513-530.
[29] Postma G,Nemec W,Kleinspehn K L. Large floating clasts in turbidites:a mechanism for their emplacement[J]. Sedimentary Geology,1988,58(1):47-61.
[30] Maizels J. Jokulhlaup deposits in proglacial areas[J]. Quaternary Science Reviews,1997,16(7):793-819.
[31] Russell A J,Knudsen O. The effects of glacier-outburst flood flow dynamics on ice-contact deposits:November 1996 J9kulhlaup,Skeiarársandur,Iceland[M]//Martini I P,Baker V R,Garzón G. Flood and megaflood processes and deposits:recent and Ancient examples. Chichester:Wiley,2002:67-83.
[32] Duller R A,Mountney N P,Russell A J,et al. Architectural analysis of a volcaniclastic jokulhlaup deposit,southern Iceland:sedimentary evidence for supercritical flow[J]. Sedimentology,2008,55(4):939-964.
[33] Waitt R B,Jr. About forty last-glacial Lake Missoula jokulhlaups through southern Washington[J]. The Journal of Geology,1980,88(6):653-679.
[34] Smith G A. Missoula flood dynamics and magnitudes inferred from sedimentology of slack-water deposits on the Columbia Plateau,Washington[J]. GSA Bulletin,1993,105(1):77-100.
[35] Shaw J,Munro-Stasiuk M,Sawyer B,et al. The channeled scabland:back to Bretz?[J]. Geology,1999,27(7):605-608.
[36] Murray A S,Wintle A G. Luminescence dating of quartz using an improved single-aliquot regenerative-dose protocol[J]. Radiation Measurements,2000,32(1):57-73.
[2] Costa J E,Schuster R L. The formation and failure of natural dams[J]. GSA Bulletin,1988,100(7):1054-1068.
[3] Dai F C,Lee C F,Deng J H,et al. The 1786 earthquake-triggered landslide dam and subsequent dam-break flood on the Dadu River,Southwestern China[J]. Geomorphology,2005,65(3/4):205-221.
[4] Chen J,Dai F C,Lv T Y,et al. Holocene landslide-dammed lake deposits in the Upper Jinsha River,SE Tibetan Plateau and their ages[J]. Quaternary International,2013,298:107-113.
[5] Wang P F,Chen J,Dai F C,et al. Chronology of relict lake deposits around the Suwalong paleolandslide in the upper Jinsha River,SE Tibetan Plateau:implications to Holocene tectonic perturbations[J]. Geomorphology,2014,217:193-203.
[6]崔之久,张梅,崔鹏,等.初论堰塞湖溃坝沉积相特征[J].山地学报,2015,33(2):129-140.[Cui Zhijiu,Zhang Mei,Cui Peng,et al. Discussion on characteristics of sedimentary facies of dammedlakes outburst deposits[J]. Mountain Research,2015,33(2):129-140.]
[7] Wassmer P,Schneider J L,Pollet N,et al. Effects of the internal structure of a rock-avalanche dam on the drainage mechanism of its impoundment,Flims sturzstrom and Ilanz paleo-lake,Swiss Alps[J]. Geomorphology,2004,61(1/2):3-17.
[8] Krivonogov S K,Sheinkman V S,Mistruykov A A. Stages in the development of the Darhad dammed lake(Northern Mongolia)during the Late Pleistocene and Holocene[J]. Quaternary International,2005,136(1):83-94.
[9] Moreiras S M. Chronology of a probable neotectonic Pleistocene rock avalanche,Cordon del Plata(Central Andes),Mendoza,Argentina[J]. Quaternary International,2006,148(1):138-148.
[10]崔之久,葛道凯,关保德,等.混杂堆积与环境[M].石家庄:河北科学技术出版社,2013:1-718.[Cui Zhijiu,Ge Daokai,Guan Baode,et al. Diamicton and environment[M]. Shijiazhuang:Hebei Science and Technology Press,2013:1-718.]
[11]陈剑,崔之久.金沙江上游雪隆囊古滑坡堰塞湖溃坝堆积体的发现及其环境与灾害意义[J].沉积学报,2015,33(2):275-284.[Chen Jian,Cui Zhijiu. Discovery of outburst deposits induced by the Xuelongnang paleolandslide-dammed lake in the upper Jinsha River,China and its environmental and hazard significance[J]. Acta Sedimentologica Sinica,2015,33(2):275-284.]
[12] Zakaria A A,Johnson H D,Jackson C A L,et al. Sedimentary facies analysis and depositional model of the Palaeogene West Crocker submarine fan system,NW Borneo[J]. Journal of Asian Earth Sciences,2013,76:283-300.
[13]刘艳蕊,杨一博,方小敏,等.沉积相变迁对内陆湖泊沉积易溶盐作为古环境指标的影响:以西宁盆地为例[J].沉积学报,2014,32(1):101-109.[Liu Yanrui,Yang Yibo,Fang Xiaomin,et al. Control of sedimentary facies alternation on water soluble salts in inland lake sediments as a paleoenvironmental proxy:A case study from Xining Basin[J]. Acta Sedimentologica Sinica,2014,32(1):101-109.]
[14] Wilson R D,Schieber J. Sedimentary facies and depositional environment of the middle Devonian Geneseo formation of New York,U.S. A.[J]. Journal of Sedimentary Research,2015,85(11):1393-1415.
[15]郭岭,贾超超,朱毓,等.现代渭河西安段沉积体沉积相与岩相特征[J].沉积学报,2015,33(3):543-550.[Guo Ling,Jia Chaochao,Zhu Yu,et al. Characteristics of sedimentary facies and lithofacies of modern Weihe River in Xi’an[J]. Acta Sedimentologica Sinica,2015,33(3):543-550.]
[16] Chen L Q,Guo F S,Tang C. Evolution of the Late Cretaceous Yongfeng-Chongren Basin in Jiangxi Province,southeast China:insights from sedimentary facies analysis and pebble counting[J].Journal of Mountain Science,2016,13(2):342-351.
[17] Khawfany A A,Aref M A,Taj R J. Human-induced changes in sedimentary facies and depositional environments, Sarum area,Red Sea coast,Saudi Arabia[J]. Environmental Earth Sciences,2017,76:61.
[18]邓世彪,关平,张鹏飞.东营凹陷青南地区沙四上亚段物源沉积体系与滩坝分布[J].沉积学报,2017,35(3):561-576.[Deng Shibiao,Guan Ping,Zhang Pengfei. Provenance,sedimentary system and beach bar distribution of the Upper Es4in Qingnan area,Dongying Depression[J]. Acta Sedimentologica Sinica,2017,35(3):561-576.]
[19] Ma J X,Chen J,Cui Z J,et al. Sedimentary evidence of outburst deposits induced by the Diexi paleolandslide-dammed lake of the upper Minjiang River in China[J]. Quaternary International,2018,464(Part B):460-481.
[20]张岳桥,李海龙,李建华.青藏高原东缘中更新世伸展作用及其新构造意义[J].地质评论,2010,56(6):781-791.[Zhang Yueqiao,Li Hailong,Li Jianhua. Middle Pleistocene extension along the eastern margin of Xizang(Tibetan)Plateau and its Neotectonic significance[J]. Geological Review,2010,56(6):781-791.]
[21] Kataoka K S. Geomorphic and sedimentary evidence of a gigantic outburst flood from Towada caldera after the 15 ka Towada-Hachinohe ignimbrite eruption,northeast Japan[J]. Geomorphology,2011,125(1):11-26.
[22] Russell A J,Knudsen O. An ice-contact rhythmite(turbidite)succession deposited during the November 1996 catastrophic outburst flood(j9kulhlaup),Skeiarárj9kull,Iceland[J]. Sedimentary Geology,1999,127(1/2):1-10.
[23] Carling P A. Freshwater megaflood sedimentation:what can we learn about generic processes?[J]. Earth-Science Reviews,2013,125:87-113.
[24] Walker R G. Facies models[M]. Canada:Geological Association of Canada,1982.
[25] Cutler P M,Colgan P M,Mickelson D M. Sedimentologic evidence for outburst floods from the Laurentide Ice Sheet margin in Wisconsin,USA:implications for tunnel-channel formation[J]. Quaternary International,2002,90(1):23-40.
[26] Benn D I,Owen L A,Finkel R C,et al. Pleistocene lake outburst floods and fan formation along the eastern Sierra Nevada,California:implications for the interpretation of intermontane lacustrine records[J]. Quaternary Science Reviews,2006,25(21/22):2729-2748.
[27] Smith G A. Coarse-grained nonmarine volcaniclastic sediment:terminology and depositional process[J]. GSA Bulletin,1986,97(1):1-10.
[28] Todd S P. Stream-driven,high-density gravelly traction carpets:possible deposits in the trabeg conglomerate formation,SW Ireland and some theoretical considerations of their origin[J]. Sedimentology,1989,36(4):513-530.
[29] Postma G,Nemec W,Kleinspehn K L. Large floating clasts in turbidites:a mechanism for their emplacement[J]. Sedimentary Geology,1988,58(1):47-61.
[30] Maizels J. Jokulhlaup deposits in proglacial areas[J]. Quaternary Science Reviews,1997,16(7):793-819.
[31] Russell A J,Knudsen O. The effects of glacier-outburst flood flow dynamics on ice-contact deposits:November 1996 J9kulhlaup,Skeiarársandur,Iceland[M]//Martini I P,Baker V R,Garzón G. Flood and megaflood processes and deposits:recent and Ancient examples. Chichester:Wiley,2002:67-83.
[32] Duller R A,Mountney N P,Russell A J,et al. Architectural analysis of a volcaniclastic jokulhlaup deposit,southern Iceland:sedimentary evidence for supercritical flow[J]. Sedimentology,2008,55(4):939-964.
[33] Waitt R B,Jr. About forty last-glacial Lake Missoula jokulhlaups through southern Washington[J]. The Journal of Geology,1980,88(6):653-679.
[34] Smith G A. Missoula flood dynamics and magnitudes inferred from sedimentology of slack-water deposits on the Columbia Plateau,Washington[J]. GSA Bulletin,1993,105(1):77-100.
[35] Shaw J,Munro-Stasiuk M,Sawyer B,et al. The channeled scabland:back to Bretz?[J]. Geology,1999,27(7):605-608.
[36] Murray A S,Wintle A G. Luminescence dating of quartz using an improved single-aliquot regenerative-dose protocol[J]. Radiation Measurements,2000,32(1):57-73.