甘肃平凉地区奥陶系平凉组重力流与等深流交互作用的沉积研究

详细信息    查看全文 | 推荐本文 |

英文篇名：Interaction Between Gravity Flow Deposits and Contourite Deposits in the Ordovician Pingliang Formation,Pingliang Region, Gansu Province 作者：严世帮 ; 李华 ; 王季欣 英文作者：Yan Shibang;Li Hua;Wang Jixin;Chengdu University of Technology; 关键词：鄂尔多斯盆地 ; 奥陶纪 ; 平凉组 ; 浊流 ; 碎屑流 ; 等深流 英文关键词：Turbidity current;;Debris flow;;Contour current;;Pingliang Formation;;Ordos Basin 中文刊名：HXYQ 英文刊名：Marine Origin Petroleum Geology 机构：成都理工大学沉积地质研究院;长江大学地球科学学院; 出版日期：2018-01-15 出版单位：海相油气地质 年：2018 期：v.23 基金：国家自然科学基金项目“鄂尔多斯盆地西南缘中奥陶统重力流与等深流交互作用沉积研究”(编号:41502101)资助 语种：中文; 页：HXYQ201801002 页数：8 CN：01 ISSN：33-1328/P 分类号：15-22

摘要

以野外露头资料为基础,对甘肃平凉地区奥陶系平凉组重力流及等深流交互作用沉积进行了研究。研究表明,平凉组以砂屑灰岩及泥岩为主,局部见砾屑灰岩;典型岩相包括水平层理页岩相、块状层理砾屑灰岩相、块状层理砂屑灰岩相、粒序层理砂屑灰岩相及透镜状交错层理砂屑灰岩相等5种类型,相应地分别代表深水原地沉积、碎屑流沉积、浊流沉积和等深流沉积。等深流在从东向西大致平行斜坡的运动过程中,在西部由于秦岭—祁连海槽的限制作用,可能导致能量局部增强。平凉组从下至上,重力流沉积规模逐渐减小,等深流沉积逐渐增加。在相对海平面较低时期,重力流极为活跃,等深流作用较弱;在相对海平面上升时期,重力流能量则减弱,等深流作用逐渐显著。等深流可对早期重力流沉积进行搬运、改造、再沉积,进而形成等深流沉积;相反,早期等深流沉积可能会受到后期重力流沉积的侵蚀、破坏。
        The interaction between gravity flow deposits and contourite deposits has been researched based on the outcrop in Ordovician Pingliang Formation of Pingliang region in Gansu province. It is shown that calcarenite and shale are the mainly lithology of Pingliang Formation, and partly with some calcirudite. It is determined that five typical lithofacies include horizontal bedding shale, massive calcirudite, massive calcarenite, graded bedding calcarenite and lenticular cross bedding calcarenite, which correspond to in situ deep-water deposits, debris flow deposits, turbidites and contourites. The energy of the contour current which moved from east to west paralleling to the slope, might be enhanced in the confined environments of Qinling-Qilian Trough. The scale of gravity flow deposits became weaker from the bottom up in Pingliang Formation, while the scale of contourite deposits became stronger. It is concluded that gravity flow was active and the effect of contour current was weak when the relative sea-level was low, and vice versa. The early gravity flow deposits can be subject to transpotation, reconstruction, redeposition by the contour current and then contourites come into being, on the contrary, it is possible that the early contourites are eroded and destroyed by the gravity flow.

引文

[1]王英民,王海荣,邱燕,等.深水沉积的动力学机制和响应[J].沉积学报,2007,25(4):495-504.
    [2]Mulder T,Faugères J C,Gonthier E.Mixed turbidite-contourite systems[M]//Rebesco M,Camerienghi A.Developments in Sedimentology,Volume 1,Number 60.Amsterdam:Elsevier,2008:435-456.
    [3]Shanmugam G.Deep-marine tidal bottom currents and their reworked sands in modern and ancient submarine canyons[J].Marine and Petroleum Geology,2003,20(5):471-491.
    [4]吴胜和,冯增昭.鄂尔多斯地区西缘及南缘中奥陶统平凉组重力流沉积[J].石油与天然气地质,1994,15(3):226-234.
    [5]高振中,罗顺社,何幼斌.鄂尔多斯西缘奥陶纪海底扇沉积体系[J].石油与天然气地质,1995,16(2):119-125.
    [6]高振中,罗顺社,何幼斌,等.鄂尔多斯地区西缘中奥陶世等深流沉积[J].沉积学报,1995,13(4):16-25.
    [7]屈红军,梅志超,李文厚,等.陕西富平地区中奥陶统等深流沉积的特征及其地质意义[J].地质通报,2010,29(9):1304-1309.
    [8]王振涛,周洪瑞,王训练,等.鄂尔多斯盆地西、南缘奥陶纪地质事件群耦合作用[J].地质学报,2015,89(11):1990-2004.
    [9]郭彦如,赵振宇,徐旺林,等.鄂尔多斯盆地奥陶系层序地层格架[J].沉积学报,2014,32(1):44-60.
    [10]Song Shuguang,Niu Yaoling,Su Li,et al.Tectonics of the North Qilian orogen,NW China[J].Gondwana Research,2013,23:1378-1401.
    [11]李文厚,梅志超,陈景维,等.富平地区中—晚奥陶世沉积的古斜坡与古流向[J].西安地质学院学报,1991,13(2):36-41.
    [12]陈小炜,牟传龙,周恳恳,等.鄂尔多斯西缘中晚奥陶世大坪阶—艾家山阶岩相古地理[J].中国地质,2014,41(6):2028-2038.
    [13]李华,何幼斌,黄伟,等.鄂尔多斯盆地南缘奥陶系平凉组等深流沉积[J].古地理学报,2016,18(4):631-642.
    [14]Hernández-Molina F J,Llave E,Stow D A V.Continental slope contourites[M]//Rebesco M,Camerlenghi A.Developments in Sedimentology,Volume 1,Number 60.Amsterdam:Elsevier,2008:379-408.
    [15]Hernández-Molina F J,Sierro F J,Llave E,et al.Evolution of the gulf of Cadiz margin and southwest Portugal contourite depositional system:Tectonic,sedimentary and paleoceanographic implications from IODP expedition 339[J].Marine Geology,2016,377(8):7-39.