Type and Evolution of Deep-Water Channel Deposits of Ordovician Lashizhong Formation in Western Margin of Ordos Basin
-
摘要: 深水水道沉积是深水区重要沉积类型之一,对其形成机制研究不仅能提高深水沉积认识,还能为油气勘探提供帮助.以露头资料为基础,对鄂尔多斯盆地西缘奥陶系拉什仲组深水水道形成机制进行了详细研究.拉什仲组岩性以灰绿色页岩及砂岩为主,另见少量的粉砂岩及砾岩.槽模、交错层理、粒序层理及变形构造等发育.总体反映深水沉积环境,重力流沉积较为发育.其中,深水水道沉积极为典型.根据形态、结构及沉积方式等,将研究区深水水道沉积划分为限制型和非限制型水道沉积.前者包括复合型及垂向加积型水道沉积,后者由迁移型及孤立型小水道沉积组成.复合型水道沉积厚约7.5 m,岩性以粗砂岩为主,底部见砾岩,水道轴部沉积、次级水道及水道-堤岸复合体沉积发育,可分为早期、中期和晚期.垂向加积型水道沉积宽为12.4 m,厚为1.3 m,宽深比为9.54,以中砂岩及细砂岩为主,水道内部以层状砂岩充填为主.迁移型水道沉积宽为6.9~12.3 m,厚为0.23~0.73 m,宽厚比14.11~53.48,以中-细砂岩为主,具有明显的北西向迁移特征;孤立型小水道沉积宽为0.5~0.6 m,厚为0.15~0.25 m,宽厚比为2.4~3.33,多为细砂-粉砂岩组成,透镜状,规模小.重力流爆发初期,能量高,侵蚀作用强,发育复合型及垂向加积型水道沉积;重力流中-后期,能量逐渐降低,迁移型水道沉积开始发育;在重力流后期及末期,其能量进一步降低,发育孤立型小水道沉积.而在空间位置上,复合型及垂向加积型水道沉积多发育在斜坡中上部,中部及下部发育迁移型水沉积道,斜坡脚及深海盆地以孤立型小水道沉积最为发育.Abstract: The deep-water channel sedimentary type is one of important sedimentary types in the deep-water zone. Research on the mechanism of deep-water channel not only can improve acquaintance of deep-water deposits, but also is helpful to oil and gas exploration. Mechanism of the deep-water channel of the Ordovician Lashizhong Formation in western margin of the Ordos basin was detailedly worked based on outcrop. The lithology of Lashizhong Formation consists of greyish-green mudstone and sandstone and few siltstone and conglomeration with flute cast, cross bedding, graded bedding and deformation structure, which suggests deep-water environment. Gravity flow deposits are well developed. The deep-water channel deposits are also typical. It is found in this study that the deep-water channel deposits could be divided into confined and non-confined channels, based on the morphology, structure, and sedimentary style. The former includes complex and vertical aggradation channel deposits. The latter can be subdivided into migrational channel and isolated small channel deposits. The lithology of complex channel deposits is coarse sandstone and conglomeration in the bottom, containing channel axis deposit, secondary channel and channel-levee system deposits, with 7.5 m in width, which could be divided into developmental, mature and decline phases. The vertical aggradation channel deposits are bedded medium and fine sandstone, with 12.4 m in width, 1.3 m in thickness, and the width-to-thickness ratio of 9.54. The migrational channel is medium to fine sandstone with northwestward migration. The width is 6.9-12.3 m, the thickness is 0.23-0.73 m, and width-to-thickness ratios range from 14.11-53.48. The isolated small channel deposits consist of fine sandstone and siltstone, lenticular shaped, small scale with 0.5-0.6 m in width, 0.15-0.25 m in thickness, and the width-to-thickness ratios of 2.4-3.33. The complex and vertical aggradation channel deposits develop when gravity flow outbreaks. Its energy is usually high with strong erosive power. The migrational channel deposits develop when gravity flow is in middle to later phases when their energy is damped. And the isolated small channel deposits develop during last phase of gravity flow. Its energy further decreases. In the spatial position, the complex and vertical channel deposits usually develop in the middle-upper part of slope. Migrational channel deposits form in the middle-lower slope, and isolated small channel deposits commonly grow in toe of slope and deep-water basin.
-
Key words:
- channel /
- turbidity current /
- Lashizhong Formation /
- Ordovician /
- Ordos basin /
- petroleum geology
-
图 1 研究区位置及岩性特征
a和b为研究区位置及环境(据孙宜朴等,2008);c为拉什仲组沉积特征(据肖彬等, 2014, 有修改)
Fig. 1. The location and lithology of the study area
图 4 迁移型水道特征
a~c.迁移型水道,拉什仲组第一段,北西向迁移特征;a肖彬等(2014);d.迁移型水道,拉什仲组第三段,水道具北西向迁移特征;e.爱尔兰北部石炭系Ross组迁移水道,侧积体发育
Fig. 4. Characteristics of migrational channels
表 1 研究区水道沉积特征
Table 1. Sedimentary characteristics of channels in the study area
类型 沉积单元 规模 形状 岩性 沉积构造 沉积序列 重力流类型 沉积过程 限制型水道沉积 复合型水道沉积 轴部沉积、水道、溢流/堤岸 大 透镜状,“U”形、“V”形、复合形 砂岩为主,少量砾岩 槽模、平行层理、粒序层理、交错层理 下粗上细 碎屑流、浊流 侵蚀、过路、沉积 垂向加积型水道沉积 轴部沉积、水道 较大 “U”形、“V”形 砂岩为主,少量粉砂岩 侵蚀面、平行层理、粒序层理 下粗上细 浊流 过路、沉积 非限制型水道沉积 迁移型水道沉积 水道、侧积体、溢流/堤岸 大 “U”形 砂岩 粒序层理、平行层理 下粗上细 浊流 过路、沉积 孤立型小水道沉积 水道、溢流/堤岸 小 “U”形 砂岩,粉砂岩 平行层理,变形构造 下粗上细 浊流 沉积 -
[1] Biscara, L., Mulder, T., Gonthier, E., et al., 2010. Migrating Submarine Furrows on Gabbonese Margin (West Africa) from Miocene to Present:Influence of Bottom Currents? Geo-Temas, 11:21-22. http://www.vliz.be/en/imis?refid=240740 [2] Clark, J. D., Pickering, K. T., 1996. Architectural Elements and Growth Patterns of Submarine Channels:Application to Hydrocarbon Exploration.AAPG Bulletin, 80(2):194-221.https://doi.org/10.1306/64ed878c-1724-11d7-8645000102c1865d http://aapgbull.geoscienceworld.org/content/80/2/194 [3] Deptuck, M.E., Steffens, G.S., Barton, M., et al., 2003.Architecture and Evolution of Upper Fan Channel-Belts on the Niger Delta Slope and in the Arabian Sea.Marine and Petroleum Geology, 20(6-8):649-676. https://doi.org/10.1016/j.marpetgeo.2003.01.004 [4] Fei, A.W., 2001.Study of Trace Fossil Assemblage and Paleoenvironment of Middle Ordovician Lashizhong Formation, Ordos Basin.Geological Journal of China Universities, 7(3):35-44 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTotal-GXDX200103003.htm [5] Gao, Z.Z., Luo, S.S., He, Y.B., 1995.Ordovician Submarine Fan Systems in West Margin of Ordos.Oil & Gas Geology, 16(2):119-125 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTotal-SYYT502.003.htm [6] Gül, M., Cronin, B.T., Gürbüz, K., 2012.Confined Deep Water System Development on the Accretionary Wedge (Miocene, Kahramanmaraş Foreland Basin, S Turkey).Earth-Science Reviews, 114(3-4):195-217. https://doi.org/10.1016/j.earscirev.2012.06.002 [7] He, Y.L., Xie, X.N., Kneller, B.C., et al., 2013.Architecture and Controlling Factors of Canyon Fills on the Shelf Margin in the Qiongdongnan Basin, Northern South China Sea.Marine and Petroleum Geology, 41(Suppl.):264-276.https://doi.org/10.1016/j.marpetgeo.2012.03.002 http://linkinghub.elsevier.com/retrieve/pii/S0264817212000608 [8] Jin, H.J., Sun, M.L., Li, Y.C., 2005.The "Sepical" Turbidites Measure of the Middle Ordovician Series in Zhuozishan Area, Inner Mongolia.Acta Sedimentologica Sinica, 23(1):34-40 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-CJXB200501004.htm [9] Keevil, G.M., Peakall, J., Best, J.L., 2007.The Influence of Scale, Slope and Channel Geometry on the Flow Dynamics of Submarine Channels.Marine and Petroleum Geology, 24(6-9):487-503. https://doi.org/10.1016/j.marpetgeo.2007.01.009 [10] Kolla, V., 2007.A Review of Sinuous Channel Avulsion Patterns in Some Major Deep-Sea Fans and Factors Controlling Them.Marine and Petroleum Geology, 24(6-9):450-469. https://doi.org/10.1016/j.marpetgeo.2007.01.004 [11] Kolla, V., Posamentier, H.W., Wood, L.J., 2007.Deep-Water and Fluvial Sinuous Channels-Characteristics, Similarities and Dissimilarities, and Modes of Formation.Marine and Petroleum Geology, 24(6-9):388-405. https://doi.org/10.1016/j.marpetgeo.2007.01.007 [12] Li, H., He, Y.B., Huang, W., et al., 2016.Contourites of the Ordovician Pingliang Formation in Southern Margin of Ordos Basin.Journal of Palaeogeography, 18(4):631-641 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTotal-GDLX201604013.htm [13] Li, H., He, Y.B., Huang, W., et al., 2018.Research on Relationship between Characteristics of Deep-Water Deposits and Palaeoenvironment in the Ordovician, Pingliang Formation, Southern Margin of the Ordos Basin:A Case of Zhaolaoyu Countryside, Fuping Town, Shaanxi Province.Acta Sedimentologica Sinica, 36(2):93-109 (in Chinese with English abstract). [14] Li, H., He, Y.B., Liu, Z.R.Z., et al., 2017.Characteristic of Gravity Flow Deposit in Pingliang Formation of Ordovician the Southwest Margin of the Ordos Basin.China Science Paper, 12(15):1774-1779 (in Chinese with English abstract). doi: 10.1007/s00367-011-0253-z [15] Li, H., He, Y.B., Wang, Z.Q., 2011.Morphology and Characteristics of Deep Water High Sinuous Channel-Levee System.Journal of Palaeogeography, 13(2):139-149 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-GDLX201102004.htm [16] Li, H., Wang, Y.M., Xu, Q., et al., 2013.Characteristics and Processes of Deep Water Unidirectionally-Migrating Channel-Levee System.Geoscience, 27(3):653-661 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-XDDZ201303017.htm [17] Li, H., Wang, Y., Zhu, W., et al., 2013.Seismic Characteristics and Processes of the Plio-Quaternary Unidirectionally Migrating Channels and Contourites in the Northern Slope of the South China Sea.Marine and Petroleum Geology, 43:370-380. https://doi.org/10.13039/501100001809 [18] Li, X.D., Que, Y., Huan, Y.Q., 2017.Analysis of Vertical Sedimentary Successions in the Lower Part of Kelimoli Formation, Middle Ordovician, Zhuozishan Area.Advances in Earth Science, 32(3):276-291 (in Chinese with English abstract). http://www.adearth.ac.cn/EN/Y2017/V32/I3/276 [19] Mayall, M., Jones, E., Casey, M., 2006.Turbidite Channel Reservoirs-Key Elements in Facies Prediction and Effective Development.Marine and Petroleum Geology, 23(8):821-841. https://doi.org/10.1016/j.marpetgeo.2006.08.001 [20] Peakall, J., Amos, K.J., Keevil, G.M., et al., 2007.Flow Processes and Sedimentation in Submarine Channel Bends.Marine and Petroleum Geology, 24(6-9):470-486. https://doi.org/10.1016/j.marpetgeo.2007.01.008 [21] Peakall, J., McCaffrey, B., Kneller, B., 2000.A Process Model for the Evolution, Morphology, and Architecture of Sinuous Submarine Channels.Journal of Sedimentary Research, 70(3):434-448. https://doi.org/10.1306/2dc4091c-0e47-11d7-8643000102c1865d [22] Posamentier, H.W., 2003.Depositional Elements Associated with a Basin Floor Channel-Levee System:Case Study from the Gulf of Mexico.Marine and Petroleum Geology, 20(6-8):677-690. https://doi.org/10.1016/j.marpetgeo.2003.01.002 [23] Rasmussen, S., Lykke-Andersen, H., Kuijpers, A., et al., 2003.Post-Miocene Sedimentation at the Continental Rise of Southeast Greenland:The Interplay between Turbidity and Contour Currents.Marine Geology, 196(1-2):37-52. https://doi.org/10.1016/s0025-3227(03)00043-4 [24] Séranne, M., Abeigne, C.R.N., Lopez, N., 2000.Reply to 'Oligocene to Holocene Sediment Drifts and Bottom Currents on the Slope of Gabon Continental Margin (West Africa):Consequences for Sedimentation and Southeast Atlantic Upwelling', Sedimentary Geology 128, 179-199 (1999).Sedimentary Geology, 136(3-4):163-168. https://doi.org/10.1016/s0037-0738(00)00094-4 [25] Sun, Y.P., Wang, C.G., Wang, Y., et al., 2008.Geochemical Characteristics and Exploration Potential of Middle Ordovician Pingliang Formation in the Ordos Basin.Petroleum Geology & Experiment, 30(2):162-168 (in Chinese with English abstract). http://linkinghub.elsevier.com/retrieve/pii/S0264817217302532 [26] Wang, Z.T., Zhou, H.R., Wang, X.L., et al., 2015.Ordovician Geological Events Group in the West and South Ordos Basin.Acta Geologica Sinica, 89(11):1990-2004 (in Chinese with English abstract). http://www.en.cnki.com.cn/Article_en/CJFDTOTAL-DZXE201511011.htm [27] Wu, S.H., Feng, Z.Z., Zhang, J.S., 1994.Sedimentology of Gravity Flow Deposits of Middle Ordovician Pingliang Formation in West and South Margins of Ordos.Oil & Gas Geology, 15(3):226-234 (in Chinese with English abstract). doi: 10.1007/s00367-011-0253-z [28] Wynn, R.B., Cronin, B.T., Peakall, J., 2007.Sinuous Deep-Water Channels:Genesis, Geometry and Architecture.Marine and Petroleum Geology, 24(6-9):341-387. https://doi.org/10.1016/j.marpetgeo.2007.06.001 [29] Xiao, B., He, Y.B., Luo, J.X., et al., 2014.Submarine Channel Complex Deposits of the Middle Ordovician Lashizhong Formation in Zhuozishan Area, Inner Mongolia.Geological Review, 60(2):321-331 (in Chinese with English abstract). http://en.cnki.com.cn/Article_en/CJFDTOTAL-DZLP201402008.htm [30] Zhu, M., Graham, S., Pang, X., et al., 2010.Characteristics of Migrating Submarine Canyons from the Middle Miocene to Present:Implications for Paleoceanographic Circulation, Northern South China Sea.Marine and Petroleum Geology, 27(1):307-319. https://doi.org/10.1016/j.marpetgeo.2009.05.005 [31] 费安玮, 2001.鄂尔多斯盆地拉什仲组遗迹化石组合与古环境.高校地质学报, 7(3):35-44. http://industry.wanfangdata.com.cn/dl/Detail/Periodical?id=Periodical_gxdzxb200103004 [32] 高振中, 罗顺社, 何幼斌, 1995.鄂尔多斯西缘奥陶纪海底扇沉积体系.石油与天然气地质, 16(2):119-125. doi: 10.11743/ogg19950204 [33] 晋慧娟, 孙明良, 李育慈, 2005.内蒙古桌子山中奥陶统的"特殊"浊积岩系.沉积学报, 23(1):34-40. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=cjxb200501005 [34] 李华, 何幼斌, 黄伟, 等, 2016.鄂尔多斯盆地南缘奥陶系平凉组等深流沉积.古地理学报, 18(4):631-642. doi: 10.7605/gdlxb.2016.04.047 [35] 李华, 何幼斌, 黄伟, 等, 2018.鄂尔多斯盆地南缘奥陶系平凉组深水沉积特征及其与古环境关系——以陕西富平赵老峪地区为例.沉积学报, 36(2):93-109. http://www.oalib.com/paper/4897422 [36] 李华, 何幼斌, 刘朱睿鸷, 等, 2017.鄂尔多斯盆地西南缘奥陶系平凉组重力流沉积特征.中国科技论文, 12(15):1774-1779. doi: 10.3969/j.issn.2095-2783.2017.15.017 [37] 李华, 何幼斌, 王振奇, 2011.深水高弯度水道-堤岸沉积体系形态及特征.古地理学报, 13(2):139-149. doi: 10.7605/gdlxb.2011.02.002 [38] 李华, 王英民, 徐强, 等, 2013.深水单向迁移水道-堤岸沉积体系特征及形成过程.现代地质, 27(3):653-661. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=xddz201303017 [39] 李向东, 阙易, 郇雅棋, 2017.桌子山中奥陶统克里摩里组下段薄层状石灰岩垂向序列分析.地球科学进展, 32(3):276-291. http://www.adearth.ac.cn/CN/abstract/abstract4240.shtml [40] 孙宜朴, 王传刚, 王毅, 等, 2008.鄂尔多斯盆地中奥陶统平凉组烃源岩地球化学特征及勘探潜力.石油实验地质, 30(2):162-168. doi: 10.11781/sysydz200802162 [41] 王振涛, 周洪瑞, 王训练, 等, 2015.鄂尔多斯盆地西、南缘奥陶纪地质事件群耦合作用.地质学报, 89(11):1990-2004. http://www.oalib.com/paper/4874870 [42] 吴胜和, 冯增昭, 张吉森, 1994.鄂尔多斯地区西缘及南缘中奥陶统平凉组重力流沉积.石油与天然气地质, 15(3):226-234. doi: 10.11743/ogg19940306 [43] 肖彬, 何幼斌, 罗进雄, 等, 2014.内蒙古桌子山中奥陶统拉什仲组深水水道沉积.地质论评, 60(2):321-331. http://www.cnki.com.cn/Article/CJFDTOTAL-DZLP201402008.htm