| 埃迪卡拉系微生物碳酸盐岩沉积特征及其地质意义:以川中磨溪8井区灯影组四段为例* |
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| 引用本文： | 罗垚,谭秀成,赵东方,罗文军,刘耘,肖笛,乔占峰,曾伟.埃迪卡拉系微生物碳酸盐岩沉积特征及其地质意义:以川中磨溪8井区灯影组四段为例*[J].古地理学报,1999,22(2):278-291. |
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| 作者姓名： | 罗垚 谭秀成 赵东方 罗文军 刘耘 肖笛 乔占峰 曾伟 |
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| 作者单位： | 1.西南石油大学油气藏地质及开发工程国家重点实验室,四川成都 610500;2.中国石油集团碳酸盐岩储层重点实验室西南石油大学研究分室,四川成都 610500;3.中国石油西南油气田分公司勘探开发研究院,四川成都 610041;4.中国石油集团碳酸盐岩储层重点实验室,浙江杭州 310023 |
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| 基金项目： | Co-funded by the National Science and Technology Major Project(No.2017ZX05009-002,2017ZX05072-002)and the National Natural Science Foundation of China(No.41972099) |
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| 摘 要： | 四川盆地高石梯—磨溪地区埃迪卡拉系灯影组广泛发育一套微生物碳酸盐岩。以磨溪8井区灯影组四段(灯四段)为例,通过精细解析高频向上变浅序列的岩石学特征,发现灯四段微生物云岩及序列建造具有如下特征: (1)向上变浅序列主要由凝块石云岩、叠层石云岩和(含微生物)泥晶云岩3类构成,伴以少量微生物粘结颗粒云岩;(2)完整的典型向上变浅序列自下而上由(含微生物)泥晶云岩(A段)、平直状叠层石云岩(B段)、小型丘状叠层石云岩(C段)、分散状凝块石云岩(D段)、格架状凝块石云岩(E段)、微生物粘结颗粒云岩(F段)等6个岩性单元构成,但大量的序列由A-C-E、A-C-D、B-D、B-C-D-E等不完整的岩性单元构成,且序列顶底皆以凝块石云岩/(含微生物)泥晶云岩、叠层石云岩/(含微生物)泥晶云岩等不平整的岩性突变面或暴露面区分;(3)埃迪卡拉系微生物碳酸盐岩发育于浪基面之上至平均海平面附近的相对高能区域,且凝块石云岩较叠层石云岩形成的环境能量高。该研究结果不仅揭示出较高能的浅水环境控制了规模性微生物岩分布这一规律,而且对区域储集层预测具有指导意义,同时也因建立了有别于现代微生物的环境分布模式而具有重要的沉积学意义。
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| 关 键 词： | 微生物岩 微生物丘 沉积模式 灯影组 震旦系 四川盆地 |
| 收稿时间： | 25 June 2019 |
Sedimentary model and controlling factors of modern beach-bar sediments in east coast of Xiashan Lake in Shandong Province |
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| Bai Li-Ke,Qiu Long-Wei,Yang Yong-Qiang,Du Shuang-Hu,Yang Bao-Liang,Han Xiao-Tong.Sedimentary model and controlling factors of modern beach-bar sediments in east coast of Xiashan Lake in Shandong Province[J].Journal of Palaeogeography,1999,22(2):278-291. |
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| Authors: | Bai Li-Ke Qiu Long-Wei Yang Yong-Qiang Du Shuang-Hu Yang Bao-Liang Han Xiao-Tong |
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| Institution: | 1.State Key Laboratory of Oil and Gas Geology and Exploitation,Southwest Petroleum University,Chengdu 610500,China;2.Research Branch of Southwest Petroleum University,Key Laboratory of Carbonate Reservoirs,CNPC,Chengdu 610500, China;3.Research Institute of Exploration and Development,PetroChina Southwest Oil & Gasfield Company,Chengdu 610041,China;4.Key Laboratory of Carbonate Reseviors, CNPC,Hangzhou 310023, China |
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| Abstract: | Beach-bars, one of the important hydrocarbon reservoirs formed in the coastal zone,become the exploration target in terms of subtle reservoirs. In order to figure out the sedimentary model of beach bars deposited in the east coast of Xiashan Lake,a detailed study on sedimentary characteristics and controlling factors of beach-bars was carried out by using ground penetrating radar (GPR) and grain size analysis. The results show that,the east coast of Xiashan Lake has developed two types of sedimentary systems including beach bars and eolian dunes. The eolian sediments in the early stage are well-sorted fine-grained sandstones, which are characterized by large tabular cross-bedding and two-segment pattern on grain size cumulative frequency plot. The beach bars sediments are reverse graded medium-grained sandstone and feature the low-continuity tabular cross-bedding. Plant roots,scouring structure,interbedding of sand and mud and three-segment pattern on on grain size cumulative frequency plot arethe typical characteristics of beach￣bar deposits. The saltation proportion is divided into two different parts indicating high energy hydrodynamic condition. Layered reflecting structures can be confirmed through GPR which implies the eolian sediments depositional pattern. The analyses of environmentally sensitive components of the grain size of eolian sediments suggest two different hydrodynamic environment. In conclusion,eolian sediments and the change of paleogeomorphy environment depend on wind action. The coastal erosion plays an important role in the early stage of the position and sand supply for beach bars. According to the sedimentary model as well as its formation mechanism,we propose a ‘wind transporting-wave modifying’ sedimentary system,which will be helpful for identification of beach bars and the prediction of favorable reservoir. |
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| Keywords: | Xiashan Lake beach-bar eolian dune sedimentary model controlling factor |
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