山东东营凹陷新近系明化镇组天文地层研究  

Astrostratigraphic research on the Neogene Minghuazhen Formation in Dongying Sag,Shandong Province

作　　者：徐道一[1] 姚益民[2] 韩延本[3] 尹志强[3] 张海峰[2] 

机构地区：[1]中国地震局地质研究所,北京100029 [2]中国石化胜利油田有限公司地质科学研究院,山东东营257015 [3]中国科学院国家天文台,北京100012

出　　处：《古地理学报》2008年第3期287-296,共10页Journal of Palaeogeography：Chinese Edition

基　　金：国家自然科学基金项目(编号:10373017);中石化“东营凹陷成烃成藏定量研究”课题;国家自然科学主任基金项目(编号:40542007)资助

摘　　要：东营凹陷明化镇组(狭义)相当于渤海湾地区明化镇组(广义)的上段。选取东营凹陷华8、郝科1等5口井的测井数据(SP、GR)进行了明化镇组天文地层研究。把本区东辛2-4井明化镇组顶界年龄值(2.588Ma BP)作为5口井明化镇组顶界年龄值,根据频谱、数字滤波和小波分析结果,得出明化镇组各段的堆积速率、延续时间,并得出明下段底界平均年龄为10.794MaBP;明上段底界平均年龄为5.121,MaBP。东营凹陷明化镇组下段与国际地层表的中新世晚期及中国区域地层表的保德阶相当;明上段的底界可对比为上新世的底界(5.332MaBP),明上段相当于中国的高庄阶和麻则沟阶。在大约11—5MaBP期间中,曾有过几次环境突变:较强的突变大约发生在10.873MaBP,较弱的是在8.9MaBP,次强的是在7MaBP,最后发生的相当强的突变是在5.11MaBP前后。根据天文地层、天文周期、地球构造气候旋回等研究成果,在11—2.6MaBP期间,地球上可能存在过大约2,Ma间隔的突变,并与区域或全球性的地层变化界线大体一致。The Minghuazhen Formation （in a narrow sense） in the Dongying Sag is correlated to the upper part of Minghuazhen Formation （in a broad sense） in the Bohai Bay area. The logging data of 5 wells from the Minghuazhen Formation in the Dongying Sag have been selected for this astrostratigraphic study. The age of the top boundary of Minghuazhen Formation in Dongxin Well 2 -4, which is located in Dongxin area, is 2. 588 Ma BP. It is taken as the age of the top boundary of Minghuazhen Formation of the above-mentioned 5 wells. Based on the results accumulation rates and duration time of various of spectral analyses, digital filter and wavelet analysis, the members of the Minghuazhen Formation have been calculated. The results indicate that the average age of bottom boundary of the Minghuazhen Formation is 10. 794 Ma BP, and the average age of bottom boundary of the upper part of Minghuazhen Formation （ Member 3） is 5. 121 Ma BP. Therefore, the lower member of Minghuazhen Formation （ Mingxia Member） corresponds to the Late Miocene of International Stratigraphic Chart （2004） or the Baodean Stage of China Regional Stratigraphic Chart （2002）. The Mingshang Member corresponds to the Gaozhuangian and Mazegouian Stages. During 11 -5 Ma BP, there were several sudden environmental changes. A rather strong change happened at about 10. 873 Ma BP, a weak one at about 8.9 Ma BP, one stronger than the previous at about 7 Ma BP, and the last quite strong change happened at about 5.11 Ma BP. According to the research results derived from astrostratigraphy, astronomical periods and tectono-climatic cycles, a duration time 2 Ma of sudden change may have occurred, which is consistent with some of the regional or global stratigraphic boundaries.

关 键 词：东营凹陷 明化镇组 中新世 上新世 天文地层 频谱分析 小波分析 

分 类 号：P534[天文地球—古生物学与地层学]