苏米尔盆地中新世海滩岩及沉积环境探讨

对苏米尔盆地布阶下、上段生物屑灰岩的野外观察和实验室岩石学、矿物学、沉积学综合分析结果表明:这些岩石具潮间带和陆上渗流—潜流带胶结特点,其沉积环境为亚热带—热带中至较低能量港湾式海滩,岩石中陆源碎屑来源于邻近区域沉积岩和较远的阿尔卑斯变质岩。     

Millennial climate changes since MIS 3 revealed by element records in deep-sea sediments from northern South China Sea

High resolution elemental MD05-2903 from the northern South records in core China Sea were obtained from XRF scanning and grain size and mineral component analyses. The K/Ti curve reveals climate changes since MIS 3 on a millennial scale, representing one of the best such records so far from deep-sea sediments of the South China Sea. When compared our K/Ti record with other climate records from high latitude ice cores and from East Asia stalagmites, variations in the K/Ti record show some typical saw-shaped features of rapid climate changes in the Northern Hemisphere. Grain size analysis reveals a close relationship between variations in K/Ti and in the fine end-member grain size. XRD analysis confirms that high K/Ti layers were dominated by K-rich weathering minerals, especially illite, while low K/Ti layers contain low illite but high abundance of Ti-rich heavy minerals. Therefore, the K/Ti record reflects changes in the input and deposition of fine weathering minerals and heavy minerals in the northern South China Sea region during stadials and interstadials. These elemental changes were largely con- trolled by variations in rainfall, erosion, and fluvial trans- portation induced by East Asia Monsoon.     

断陷湖盆陆相层序过程——响应机制的单因素计算机模拟

综合考虑陆源碎屑物供给、内源碳酸盐岩没积、沉积物侵蚀与再沉积、重力流沉积以及构造升降和水平位移等诸多地质因素,建立了一个能够模拟各型盆地的综合数学物理方程式。采用自行研制的定量层序地层模拟系统,以断陷湖盆坡带（泌阳断陷双河～赵凹地区为例）,分别模拟了：①湖平面变化过程及其陆相层序响应机制;②基底构造沉降过程及其陆相层序响应机制;③物源供给过程及其陆相层序响应机制。     

Preliminary analysis of grain-size populations with environmentally sensitive terrigenous components in marginal sea setting

Grain-size data have been widely used to determine sediment transport patterns and to reconstruct the sedi-mentary environment. Because the natural occurring sediments deposited in the geologic periods and modern times are mostly mixtures of materials transported from multi-sources or/and by different sedimentary processes, the grain size of bulk samples is an incomplete, approxi-mate index for sedimentary environment changes[1,2]. Thus, further studies on the quantitative reconstruction of th…     

陆相含油盆地泥岩中白云岩夹层的储集性研究——以东营凹陷沙三段上部白云岩为例

胜利油区东营凹陷古近系(下第三系)沙河街组第三段上部夹于泥岩中的白云岩为泥晶白云岩和泥晶铁白云岩,由晶粒细小的他形—半自形粒状白云石组成。在沉积期后变化中经历了多种成岩作用改造,其中影响白云岩储集性的作用主要为溶蚀作用、重结晶作用和构造应力作用。其储集空间主要为微粒间孔、晶间孔、溶蚀孔和构造缝,为好—较好的储层     

Preliminary analysis of grain-size populations with environmentally sensitive terrigenous components in marginal sea setting

Terrigenous components were separated from the bulk sediment of Core A7 from the Okinawa Trough and Core A37 from the Ryukru Trench and grain-size distributions of these sub-samples were analyzed.Based upon and analysis of the grain-size data of the two sedimentary sequences,grain-size populations are identified to be sensitive to sedimentary environmental changes.The modal values and size ranges of the two main grain-size populations in Core A7 are evidently different from those of Core A37,indicating the spatial variability of sediment sources and transport processes between the two places.The downcore variations in the content of the environmentally sensitive sgrain-size populations reveal that during the accumulation of sedimentary material the environment remained relatively stable at the site where Core A7 was collected,except for the apparent events for the formation of two turbidite layers and a volcanic ash layer.However,the sedimentary sequence of Core A37 shows six sedimentary cycles,indicating a highly variable sedimentary environment at this location.     

断陷湖盆陆相层序中高频层序的米氏旋回成因探讨

以泌阳断陷湖盆下第三系核三上段为例 ,通过单井高频层序分析 ,将其划分出 3个层序 9个体系域 ,发育 4类 13个小层序组 ,其中可识别的小层序达 5 0多个 ;采用滤波技术和傅里叶变换 ,对单井自然电位 (SP)测井曲线进行技术处理 ,获取其沉积旋回曲线和频谱曲线 ,以了解优势旋回的分布及旋回时限。研究结果显示 ,泌阳断陷湖盆的高频层序是由米氏旋回所驱动的古气候周期性波动所形成的。亦即 ,古气候是影响陆相层序发育的一个重要因素 ,其周期性变化是源于米氏旋回的驱动力 (即米兰柯维奇天文旋回 )。米兰柯维奇天文旋回包括偏心率旋回、倾斜率旋回和岁差旋回 ,这几个轨道参数所驱动的古气候变迁 ,分别形成了周期为 10万a (或4 0万a)、 4万a及 2万a的高频层序 ,即小层序组、小层序及小层单元。     

泌阳断陷下第三系陆相层序中油气生储盖及其组合特征——以双河-赵凹地区下第三系核三上段为例

运用层序地层学理论和分析方法 ,分析了泌阳断陷下第三系陆相层序中油气生、储、盖以及盐组合特征 .分析结果表明 :第三系陆相层序中极为有利的烃源岩为发育于高水位体系域的半深湖 -深湖泥岩 (属区域性生油层 ) ,其次是水进体系域及水退体系域的湖相泥岩 (属局部性生油层 ) ;有利的储集体分布于水进体系域和水退体系域的冲积扇——扇三角洲砂体及前扇三角洲斜坡带的滑塌性重力流扇体中 ,尤其是扇三角洲的 (水下 )分流河道、河口砂坝 (远砂坝 )及前缘席状砂体 .区域性盖层为高水位体系域的深水湖相泥岩 ,而水进和水退体系域的湖相泥岩亦可构成局部性盖层     

泌阳断陷双河赵凹地区下第三系核三上段陆相层序地层学

根据参照井处的沉积相迁移特征及体系域叠置样式,将泌阳断陷陆相层序划归为两种类型（Ⅰ型和Ⅱ型）。双河赵凹地区下第三系核三上段包括跨时分别为１．０８,１．４０和１０２（Ｍａ）的３个Ⅱ型陆相层序,由南向北呈现冲积扇扇三角洲湖泊三角洲的沉积体系空间配置。泌阳断陷陆相层序的体系域具四分性,其小层序组类型有４种：低位加积型、退积型、高位加积型和进积型。综合利用研究区的钻井、测井及地质资料,根据下第三系核三上段地震相平面展布特征,将地震相转换为沉积相,并由此归纳出研究区核三上段的沉积模式。针对研究区目的层段所划３个陆相层序发育的共同特点,建立了断陷湖盆陡坡带陆相层序地层岩相格架模式。对连井剖面层序地层进行了对比,编制了研究区目的层段的年代层序地层框架模式。     

Dynamic control on grain-size distribution of terrigenous sediments in the western South China Sea: Implication for East Asian monsoon evolution

High-resolution oxygen isotope stratigraphy of Core MD05-2901, which is located off eastern Vietnam in the western South China Sea （SCS）, was established and indicated that the core spans a time period of the past 450 ka. Based on the bulk density, fractional porosity and lithogenic content of the sediments, terrigenous mass accumulation rate （TMAR） was obtained, which is 4.9-6.0 g cm^-2 ka^-1 on average during interglacial stages, higher than that during glacial stages, i.e. 1.9-5.0 g cm^-2 ka^-1, which is different from northern and southern SCS which show higher TMAR in glacial stages. By principle component analysis of grain size distribution of all the samples, two main control factors （F1 and F2） were obtained, which are responsible for about 80% variance of granularity. The contents of grain size population 1.26-2.66 μm% and 10.8-14.3 μm% which are sensible to F1 show high-frequency fluctuation, and correlate well with the summer insolation at 15^o N. They exhibit a distinct cyclicity with frequencies near 23 ka and 13 ka, in contrast to a strong frequency peak near 100 ka obtained in proxies 4.24-7.42 μm% and 30.1-43.7 μm% controlled mainly by F2. The sedimentary character of this part of the SCS was controlled by variations of input flux from two main source areas, namely the southwest and north SCS, which were transported by different circulations of surface current forced by East Asian summer monsoon and winter monsoon respectively. We believe that the East Asian summer monsoon has fluctuated with high frequency and been forced by changes in solar insolation in low latitude associated with precession and half precession, while ice-volume forcing is probably a primary factor in determining the strength and timing of the East Asian winter monsoon but with less important insolation forcing.