Microscale sedimentary characteristics and distinguishing methods for deep-water sandy debris flow and turbidity flow in continental lakes: a case study of seventh member of Yanchang Formation, Ordos Basin
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摘要: 基于薄片观察、粒度分析、环境扫描电镜和全岩矿物定量分析、荧光光谱元素分析等测试结果,对鄂尔多斯盆地旬邑、瑶曲地区三叠系延长组长7段中的砂质碎屑流和浊流的微观沉积特征进行了研究。结果表明:(1)砂质碎屑流沉积的碎屑颗粒呈杂乱无序排列,而浊流沉积(鲍马序列A段)则有较明显的定向排列特征,反映出前者为整体快速搬运特征,而后者具有部分牵引流特征,表明其密度偏低,而二者均具有黄铁矿;(2)砂质碎屑流砂岩概率曲线具明显的两段式,反映牵引流特征,结合镜下观察,其来源应为浅水或陆上河流,而浊流砂岩则为单段式,反映重力流特征;(3)瑶曲长7沉积期古环境为干冷气候,砂质碎屑流相对浊流而言,其古环境大部分时期淋滤作用较弱;(4)砂质碎屑流砂岩及伴生泥岩的Sr/Ba值均小于浊流,表明其对湖水的稀释作用更强,注入速度更快,瑶曲整体Sr/Cu值低于旬邑,相对降雨量更丰富,此外,砂质碎屑流砂岩中重矿物Zr含量整体要高于浊流,表明其具有更强的碎屑搬运能力;(5)砂质碎屑流沉积和浊流沉积的黏土组成及混层比无明显差异,但全岩矿物成分组成有差别,通过差异性较大的石英与黏土含量制订划分模板,可将砂质碎屑流沉积、浊流沉积及两者过渡段进行定量划分。Abstract: Based on the results of thin section observation, grain size analysis, environmental scanning electron microscopy, whole rock mineral quantitative analysis and fluorescence element analysis, the microscale sedimentary characteristics of sedimentary sand debris flow and turbidity flow were studied in details after a systematic sampling of the seventh member of Yanchang Formation (Chang 7) of Xunyi and Yaoqu areas of Ordos Basin. The results showed that: (1) The clastic particles deposited in the sand debris flow were in a disordered arrangement, while the turbid flow deposition(section A of the Bouma sequence) has a more obvious directional arrangement, indicating the former is characterized by overall rapid transport, while the latter is characterized by traction flow, indicating a low density. Both of them contain pyrites. (2) The probability curve of the sand debris flow sandstones showed a two-stage pattern, reflecting the characteristics of traction and drainage. According to microscopic observation, its source could be shallow water or land river. The probability curve of the turbid flow sandstones shows a single stage pattern, reflecting the characteristics of gravity flow. (3) The paleoenvironment of the Chang 7 sedimentary period of Yaoqu area is dry and cold. The eluviation of sandy debris flow is weaker than that of turbid flow in most periods. (4) For elemental compositions, the Sr/Ba ratios of both sandy debris flow sandstonesand associated mudstones were lower than those of turbidity current, which indicates that it has stronger dilution effect on lake water and faster injection speed. The Sr/Cu ratios of Yaoqu area were lower than those of Xunyi area, and the relative rainfall is more abundant. In addition, the Zr content in sandy debris flow sandstones is higher than that in turbidity flow sandstones, which indicates that it had stronger debris transport capacity. (5) Through the quantitative analysis of the whole rock and clay by X-ray diffraction, there is no obvious difference in clay composition and mixed layer ratio between them, but there were differences in mineral composition of the whole rock. Since the contents of quartz and clay showed great difference, a division template of them has been established, which can quantitatively distinguish sandy debris flow sandstones, turbidity flow sandstones and the transition section.
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图 3 鄂尔多斯盆地瑶曲和旬邑地区三叠系延长组长7段砂质碎屑流与浊流砂岩分类
图版据曾允孚等[11](1986)。
Figure 3. Classification of sand debris flow and turbidite flow sandstones in Chang 7 of Yanchang Formation, Yaoqu and Xunyi areas, Ordos Basin
图 6 鄂尔多斯盆地旬邑、瑶曲地区三叠系延长组长7段泥岩、砂质碎屑流砂岩与浊流砂岩元素对比分析
a.旬邑、瑶曲地区泥岩锶钡摩尔比与铁锰摩尔比对比分析;b.旬邑、瑶曲地区泥岩锶钡摩尔比与锶铜摩尔比对比分析;c.旬邑、瑶曲地区砂质碎屑流与浊流(A+B)段砂岩锶钡摩尔比与锆元素对比分析
Figure 6. Elemental compositions of mudstones, sand debris flow sandstones and turbidity flow sandstones in Chang 7 of Yanchang Formation, Yaoqu and Xunyi areas, Ordos Basin
表 1 鄂尔多斯盆地瑶曲地区三叠系延长组长7段砂质碎屑流与浊流黏土定量分析结果
Table 1. Quantitative results of clay contents in sandy debris flow and turbid flow in Chang 7 of Yanchang Formation, Yaoqu area, Ordos Basin
样品号 取样位置 岩性 黏土矿物相对含量/% I/S混层比/% I/S It Kao C 瑶曲3号样 砂质碎屑流底 砂岩 71 12 - 17 20 瑶曲4号样 砂质碎屑流顶 砂岩 73 12 - 15 20 瑶曲5号样 砂质碎屑流中 砂岩 71 13 - 16 20 瑶曲6号样 砂质碎屑流底 砂岩 68 14 - 18 20 瑶曲7号样 浊流底 砂岩 76 13 - 11 20 瑶曲8号样 浊流中 砂岩 78 14 - 8 20 瑶曲9号样 浊流A段 砂岩 76 14 - 10 20 瑶曲10号样 浊流B段 砂岩 79 10 - 11 20 注:I/S为伊蒙混层;It为伊利石;Kao为高岭石;C为绿泥石。 -
[1] SHANMUGAM G. "高密度浊流"是砂质碎屑流吗?[J]. 阙洪培, 译. 地质科学译丛, 1997, 14(1): 24-30.SHANMUGAM G. Is "high density turbidity current" a sandy clastic flow?[J]. QUE Hongpei, trans. Translated Series of Geological Sciences, 1997, 14(1): 24-30. [2] 裴羽, 何幼斌, 李华, 等. 高密度浊流和砂质碎屑流关系的探讨[J]. 地质论评, 2015, 61(6): 1281-1292. https://www.cnki.com.cn/Article/CJFDTOTAL-DZLP201506010.htmPEI Yu, HE Youbin, LI Hua, et al. Discuss about relationship between high-density turbidity current and sandy debris flow[J]. Geological Review, 2015, 61(6): 1281-1292. https://www.cnki.com.cn/Article/CJFDTOTAL-DZLP201506010.htm [3] SHANMUGAM G. Ten turbidite myths[J]. Earth-Science Reviews, 2002, 58(3/4): 311-341. [4] SHANMUGAM G. High-density turbidity currents; are they sandy debris flows?[J]. Journal of Sedimentary Research, 1996, 66(1): 2-10. [5] SHANMUGAM G. The Bouma sequence and the turbidite mind set[J]. Earth-Science Reviews, 1997, 42(4): 201-229. [6] SHANMUGAM G. 50 years of the turbidite paradigm (1950s-1990s): deep-water processes and facies models—a critical perspective[J]. Marine and Petroleum Geology, 2000, 17(2): 285-342. [7] 邹才能, 赵政璋, 杨华, 等. 陆相湖盆深水砂质碎屑流成因机制与分布特征: 以鄂尔多斯盆地为例[J]. 沉积学报, 2009, 27(6): 1065-1075. https://www.cnki.com.cn/Article/CJFDTOTAL-CJXB200906007.htmZOU Caineng, ZHAO Zhengzhang, YANG Hua, et al. Genetic mechanism and distribution of sandy debris flows in terrestrial lacustrine basin[J]. Acta Sedimentologica Sinica, 2009, 27(6): 1065-1075. https://www.cnki.com.cn/Article/CJFDTOTAL-CJXB200906007.htm [8] 李相博, 刘化清, 完颜容, 等. 鄂尔多斯盆地三叠系延长组砂质碎屑流储集体的首次发现[J]. 岩性油气藏, 2009, 21(4): 19-21. https://www.cnki.com.cn/Article/CJFDTOTAL-YANX200904004.htmLI Xiangbo, LIU Huaqing, WAN Yanrong, et al. First discovery of the sandy debris flow from the Triassic Yanchang Formation, Ordos Basin[J]. Lithologic Reservoirs, 2009, 21(4): 19-21. https://www.cnki.com.cn/Article/CJFDTOTAL-YANX200904004.htm [9] 李相博, 王菁, 廖建波, 等. 陆相盆地深水沉积中的块体搬运作用与搬运机理研究: 以鄂尔多斯盆地延长组为例[J]. 天然气地球科学, 2015, 26(4): 625-633. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201504005.htmLI Xiangbo, WANG Jing, LIAO Jianbo, et al. Research on block transport and transport mechanism in deep-water sediments of continental basins: taking Yanchang Formation in Ordos Basin as an example[J]. Natural gas earth science, 2015, 26(4): 625-633. https://www.cnki.com.cn/Article/CJFDTOTAL-TDKX201504005.htm [10] 李相博. 陆相盆地深水沉积体系研究[J]. 沉积学报, 2019, 37(5): 877-878. https://www.cnki.com.cn/Article/CJFDTOTAL-CJXB201905001.htmLI Xiangbo. Research on deep-water sedimentary system of continental basins[J]. Journal of Sedimentology, 2019, 37(5): 877-878. https://www.cnki.com.cn/Article/CJFDTOTAL-CJXB201905001.htm [11] 曾允孚, 夏文杰. 沉积岩石学[M]. 北京: 地质出版社, 1986.ZENG Yunfu, XIA Wenjie. Sedimentary petrology[M]. Beijing: Geological Publishing House, 1986. [12] 厚刚福, 徐洋, 孙靖, 等. 三角洲前缘—湖盆深水区沉积模式及意义: 以准噶尔盆地盆1井西凹陷三工河组二段一砂组为例[J]. 石油学报, 2019, 40(10): 1223-1232. https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB201910007.htmHOU Gangfu, XU Yang, SUN Jing, et al. Sedimentary model from delta front to deep water area and its significance: a case study of the first sand group of member 2 of Sangonghe Formation in the well Pen-1 west sag, Junggar Basin[J]. Acta Petrolei Sinica, 2019, 40(10): 1223-1232. https://www.cnki.com.cn/Article/CJFDTOTAL-SYXB201910007.htm [13] 操应长, 杨田, 王艳忠, 等. 深水碎屑流与浊流混合事件层类型及成因机制[J]. 地学前缘, 2017, 24(3): 234-248. https://www.cnki.com.cn/Article/CJFDTOTAL-DXQY201703027.htmCAO Yingchang, YANG Tian, WANG Yanzhong, et al. Types and genesis of deep-water hybrid event beds comprising debris flow and turbidity current[J]. Earth Science Frontiers, 2017, 24(3): 234-248. https://www.cnki.com.cn/Article/CJFDTOTAL-DXQY201703027.htm [14] 刘芬, 朱筱敏, 李洋, 等. 鄂尔多斯盆地西南部延长组重力流沉积特征及相模式[J]. 石油勘探与开发, 2015, 42(5): 577-588. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201505004.htmLIU Fen, ZHU Xiaomin, LI Yang, et al. Sedimentary characteristics and facies model of gravity flow deposits of Late Triassic Yanchang Formation in southwestern Ordos Basin, NW China[J]. Petroleum Exploration and Development, 2015, 42(5): 577-588. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201505004.htm [15] 杨华, 牛小兵, 罗顺社, 等. 鄂尔多斯盆地陇东地区长7段致密砂体重力流沉积模拟实验研究[J]. 地学前缘, 2015, 22(3): 322-332. https://www.cnki.com.cn/Article/CJFDTOTAL-DXQY201503031.htmYANG Hua, NIU Xiaobing, LUO Shunshe, et al. Research of simulated experiment on gravity flow deposits of tight sand bodies of Chang 7 formation in Longdong area, Ordos Basin[J]. Earth Science Frontiers, 2015, 22(3): 322-332. https://www.cnki.com.cn/Article/CJFDTOTAL-DXQY201503031.htm [16] 杨仁超, 何治亮, 邱桂强, 等. 鄂尔多斯盆地南部晚三叠世重力流沉积体系[J]. 石油勘探与开发, 2014, 41(6): 661-670. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201406003.htmYANG Renchao, HE Zhiliang, QIU Guiqiang, et al. Late Triassic gravity flow depositional systems in the southern Ordos Basin[J]. Petroleum Exploration and Development, 2014, 41(6): 661-670. https://www.cnki.com.cn/Article/CJFDTOTAL-SKYK201406003.htm [17] 高红灿, 郑荣才, 魏钦廉, 等. 碎屑流与浊流的流体性质及沉积特征研究进展[J]. 地球科学进展, 2012, 27(8): 815-827. https://www.cnki.com.cn/Article/CJFDTOTAL-DXJZ201208000.htmGAO Hongcan, ZHENG Rongcai, WEI Qinlian, et al. Reviews on fluid properties and sedimentary characteristics of debris flows and turbidity currents[J]. Advances in Earth Sciences, 2012, 27(8): 815-827. https://www.cnki.com.cn/Article/CJFDTOTAL-DXJZ201208000.htm [18] 陈飞, 胡光义, 孙立春, 等. 鄂尔多斯盆地富县地区上三叠统延长组砂质碎屑流沉积特征及其油气勘探意义[J]. 沉积学报, 2012, 30(6): 1042-1052. https://www.cnki.com.cn/Article/CJFDTOTAL-CJXB201206005.htmCHEN Fei, HU Guangyi, SUN Lichun, et al. Sedimentary characteristics and the significance of petroleum exploration of sandy debris flows of Yanchang Formation of the Upper Triassin, Fuxian area, Ordos Basin[J]. Acta Sedimentologica Sinica, 2012, 30(6): 1042-1052. https://www.cnki.com.cn/Article/CJFDTOTAL-CJXB201206005.htm [19] 李存磊, 任伟伟, 唐明明. 流体性质转换机制在重力流沉积体系分析中应用初探[J]. 地质论评, 2012, 58(2): 285-296. https://www.cnki.com.cn/Article/CJFDTOTAL-DZLP201202015.htmLI Cunlei, REN Weiwei, TANG Mingming. Preliminary study on gravity flow depositional system based on fluid properties conversion theory[J]. Geological Review, 2012, 58(2): 285-296. https://www.cnki.com.cn/Article/CJFDTOTAL-DZLP201202015.htm [20] 夏青松, 田景春. 浊积岩神话与砂质碎屑流[J]. 沉积与特提斯地质, 2006, 26(4): 105-108. https://www.cnki.com.cn/Article/CJFDTOTAL-TTSD200604018.htmXIA Qingsong, TIAN Jingchun. Turbidite myth and sandy debris flow[J]. Sedimentary Geology and Tethyan Geology, 2006, 26(4): 105-108. https://www.cnki.com.cn/Article/CJFDTOTAL-TTSD200604018.htm [21] 惠潇, 张海峰, 张东阳, 等. 鄂尔多斯盆地延长组湖盆中部长6厚层砂体成因分析[J]. 中国地质, 2008, 35(3): 482-488. https://www.cnki.com.cn/Article/CJFDTOTAL-DIZI200803014.htmHUI Xiao, ZHANG Haifeng, ZHANG Dongyang, et al. Origin of Chang 6 thick-bedded sand bodies of the Yanchang Formation in the central Ordos Basin[J]. Geology in China, 2008, 35(3): 482-488. https://www.cnki.com.cn/Article/CJFDTOTAL-DIZI200803014.htm [22] 杨华, 刘显阳, 张才利, 等. 鄂尔多斯盆地三叠系延长组低渗透岩性油藏主控因素及其分布规律[J]. 岩性油气藏, 2007, 19(3): 1-6. https://www.cnki.com.cn/Article/CJFDTOTAL-YANX200703002.htmYANG Hua, LIU Xianyang, ZHANG Caili, et al. The main controlling factors and distribution of low permeability lithologic reservoirs of Triassic Yanchang Formation in Ordos Basin[J]. Lithologic Reservoirs, 2007, 19(3): 1-6. https://www.cnki.com.cn/Article/CJFDTOTAL-YANX200703002.htm [23] 傅强, 吕苗苗, 刘永斗. 鄂尔多斯盆地晚三叠世湖盆浊积岩发育特征及地质意义[J]. 沉积学报, 2008, 26(2): 186-192. https://www.cnki.com.cn/Article/CJFDTOTAL-CJXB200802003.htmFU Qiang, LÜ Miaomiao, LIU Yongdou. Developmental characteristics of turbidite and its implication on petroleum geology in Late-Triassic Ordos Basin[J]. Acta Sedimentologica Sinica, 2008, 26(2): 186-192. https://www.cnki.com.cn/Article/CJFDTOTAL-CJXB200802003.htm [24] 陈全红, 李文厚, 高永祥, 等. 鄂尔多斯盆地上三叠统延长组深湖沉积与油气聚集意义[J]. 中国科学(D辑地球科学), 2007, 37(S1): 39-48. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK2007S1005.htmCHEN Quanhong, LI Wenhou, GAO Yongxiang, et al. The deep-lake deposit in the Upper Triassic Yanchang Formation in Ordos Basin, China and its significance for oil-gas accumulation[J]. Science in China(Series D Earth Sciences), 2007, 50(2): 47-58. https://www.cnki.com.cn/Article/CJFDTOTAL-JDXK2007S1005.htm [25] 王昊, 杨友运, 李元昊, 等. 鄂尔多斯盆地合水地区长7段重力流沉积特征及分布规律[J]. 西安石油大学学报(自然科学版), 2019, 34(2): 39-45. https://www.cnki.com.cn/Article/CJFDTOTAL-XASY201902006.htmWANG Hao, YANG Youyun, LI Yuanhao, et al. Characteristics and distribution of gravity flow deposition of Chang 7 member in Heshui area, Ordos Basin[J]. Journal of Xi'an Shiyou University (Natural Science Edition), 2019, 34(2): 39-45. https://www.cnki.com.cn/Article/CJFDTOTAL-XASY201902006.htm [26] 淡卫东, 邓静, 毛振华, 等. 鄂尔多斯盆地长7油层组深水重力流沉积分布特征及成因[J]. 长江大学学报(自然科学版), 2019, 16(8): 1-7. https://www.cnki.com.cn/Article/CJFDTOTAL-CJDL201908001.htmDAN Weidong, DENG Jing, MAO Zhenhua, et al. The deep-watergravity flow sedimentations in Chang7 reservoir of Triassic Yanchang Formation in Ordos Basin[J]. Journal of Yangtze University (Natural Science Edition), 2019, 16(8): 1-7. https://www.cnki.com.cn/Article/CJFDTOTAL-CJDL201908001.htm [27] 陈柄屹, 林承焰, 马存飞, 等. 陆相断陷湖盆陡坡带深水重力流沉积类型、特征及模式: 以东营凹陷胜坨地区沙四段上亚段为例[J]. 地质学报, 2019, 93(11): 2921-2934. https://www.cnki.com.cn/Article/CJFDTOTAL-DZXE201911015.htmCHEN Bingyi, LIN Chengyan, MA Cunfei, et al. Types, characteristics and sedimentary model of deep-water gravity flow deposition in the steep slope zone of terrestrial faulted lacustrine basin: a case study of the Es4s submember in the Shengtuo area of Dongying Depression[J]. Acta Geologica Sinica, 2019, 93(11): 2921-2934. https://www.cnki.com.cn/Article/CJFDTOTAL-DZXE201911015.htm [28] 余抒发. 鄂尔多斯盆地南部泾河油田长7段深水重力流沉积物储层描述研究[D]. 北京: 中国地质大学, 2019.YU Shufa. Deep-water gravity flow sediments reservoir description and modeling of the Ch7 member in the Jinghe oilfield, southern Ordos Basin, China[D]. Beijing: China University of Geosciences, 2019. [29] 晁储志. 鄂尔多斯盆地瑶曲露头区延长组深水沉积与储层特征[D]. 北京: 中国石油大学(北京), 2018.CHAO Chuzhi. Deep water sedimentary and reservoir characte-ristics in Yanchang Formation of Yaoqu outcrop zone in Ordos Basin[D]. Beijing: China University of Petroleum (Beijing), 2018. [30] RATEEV M A, GORBUNOVA Z N, LISITZYN A P, et al. The distribution of clay minerals in the oceans[J]. Sedimentology, 1969, 13(1/2): 21-43.