深水等深流沉积中记录的米兰科维奇特性——以陕西富平地区上奥陶统赵老峪组为例  

Characteristics of Milankovitch Cycles in Deep Water Contourites——A Case Study of Upper Ordovician Zhaolaoyu Formation in Fuping Area of Shaanxi,China

作　　者：冯斌 李华[1,2,3] 何幼斌[1,2,3] 苏帅亦 FENG Bin;LI Hua;HE You-bin;SU Shuai-yi(School of Geosciences,Yangtze University,Wuhan 430100,Hubei,China;Research Center of Sedimentary Basin,Yangtze University,Wuhan 430100,Hubei,China;Key Laboratory of Exploration Technologies for Oil and Gas Resources of Ministry of Education,Yangtze University,Wuhan 430100,Hubei,China)

机构地区：[1]长江大学地球科学学院,湖北武汉430100 [2]长江大学沉积盆地研究中心,湖北武汉430100 [3]长江大学油气资源与勘探技术教育部重点实验室,湖北武汉430100

出　　处：《地球科学与环境学报》2019年第1期69-82,共14页Journal of Earth Sciences and Environment

基　　金：国家自然科学基金项目(41472096;41502101)

摘　　要：陕西富平地区上奥陶统赵老峪组为深水盆地边缘至深水斜坡沉积环境,发育深水原地沉积、等深流沉积及重力流沉积。以野外实测剖面、岩相特征等资料为基础,结合米兰科维奇理论、天文地层学、古海洋学以及古气候学,系统研究该地区等深流强度与古气候、海平面、古盐度的关系。结果表明:Fischer图解可以客观、准确地反映深水沉积地层相对海平面变化;深水沉积及等深流沉积中不同级次旋回垂向组合关系记录了米兰科维奇特性,即小级别旋回在垂向上有序地按照1∶4或者1∶5的形式叠加构成较大级别旋回;等深流强度受米兰科维奇旋回影响,呈多周期弱→强→弱递变;等深流强化周期约为0.1Ma。The Upper Ordovician Zhaolaoyu Formation in Fuping area of Shaanxi develops the deep water autochthonous deposits,contourites and gravity-flow deposits,and the sedimentary environment is from the edge of the deep water basin to deep water slope.On the basis of the section measured in field and the lithofacies features,combined with Milankovitch theory,astrostratigraphy,paleoceanography,paleoclimatology and Fischer diagram,the relationships between the intensity of the contour current and changes of paleoclimate,sea level and paleosalinity were studied.The results show that Fischer diagram can reflect sea level changes objectively and accurately;the vertical combination of different grades of cycle in the deep water sediments and contourites records the characteristics of Milankovitch,showing that small scale cycles are superimposed in the vertical direction in the form of 1∶4 or 1∶5 to form the larger level of cycles;the contour current intensity is affected by Milankovitch cycle,which is reflected in the multi-cycle of weak-strong-weak change;the activity cycle of contour current is about 0.1 Ma.

关 键 词：沉积学 深水沉积 米兰科维奇旋回 等深流 轨道周期 赵老峪组 鄂尔多斯盆地 

分 类 号：P618.13[天文地球—矿床学] TE122[天文地球—地质学]