辽东湾地区锦州25—1油田油气成藏特点和运聚模拟研究     

祝春荣  韦阿娟  沈东义 《海洋地质译丛》2011,(3):17-22

在对构造演化、成藏要素、油源对比、成藏期次分析的基础上,结合Trinity油气运移成藏模拟分析软件对锦州25—1油田的油气运聚模拟研究,分析了形成锦州25—1油田的成藏主控因素,建立了其成藏模式,指出了该地区有利勘探方向。模拟分析结果表明,锦州25—1构造是辽西凹陷沙三段烃源岩生成油气运聚的有利指向区,而优良成藏要素的优势时空配置则是形成锦州25—1油田的关键因素。其成藏模式为：辽西凹陷沙三段烃源岩在东下段时期进入了大量生排烃期,生成的油气为一期充注,充注时间发生在东营组末期,沿东下段时期强烈构造运动伴生的断裂系统、沙二段广泛发育的砂体、沙二段与沙三段之间大型不整合面以及古构造脊所构成的疏导体系运移至沙二段圈闭成藏,而沙三段砂体则可以近源优势成藏。辽西凹陷西斜坡、凹中隆以及古构造脊是今后较为有利的勘探区域。  相似文献   

Constraining the genetic relationships of 25-norhopanes,hopanoic and 25-norhopanoic acids in onshore Niger Delta oils using a temperature-dependent material balance     

《Organic Geochemistry》2015

Analysis of oil samples from the Niger Delta (Nigeria) revealed a range of structurally related hopanes, including 25-norhopanes, and hopanoic and 25-norhopanoic acids. 25-Norhopanes were detected in all medium and heavily biodegraded oils and were most abundant in the heavily degraded oils. Hopanoic acids (C₃₀-C₃₃) and 25-norhopanoic acids (C₃₀-C₃₁) were most abundant in moderately degraded oils and occurred in reduced concentration in heavily degraded oils but were absent from, or in trace concentration in, slightly degraded oils. Consideration of the structures suggests that 25-norhopanoic acids form via carboxylation of 25-norhopanes or demethylation of hopanoic acids. Mass balance for the onshore Niger Delta oils suggests that formation of 25-norhopanes operates independently of 25-norhopanoic acid formation and that 25-norhopanoic acids are likely transient intermediates for only a small proportion of the 25-norhopanes.  相似文献   

Subduction initiation of Indochina and South China blocks: insight from the forearc ophiolitic peridotites of the Song Ma Suture Zone in Vietnam     

Thanh Xuan Ngo  M. Santosh  Hai Thanh Tran  Hieu Trung Pham 《Geological Journal》2016,51(3):421-442

The Song Ma region, which is located in the northwestern Vietnam represents the zone of amalgamation between Indochina and South China blocks. Numerous scattered ultramafic rocks occur in this region in association with Early to Middle Palaeozoic greenschists and paragneisses, and all these rocks were subjected to hydrous metamorphism and deformation. Here, we present new field data, mineral chemistry and geochemistry from a suite of hydrated peridotites within the Song Ma region and discuss the tectonic significances of the region. We also combine the available data within the Song Ma region and Indochina–South China blocks to discuss the tectonic evolution of the subduction zone. Based on the results, we suggest that the peridotites from the Song Ma are mantle residues that suffered a high degree of partial melting in a forearc tectonic setting. The present data together with the available data within the Song Ma region and the Indochina and South China blocks clearly represent a southward directed Middle Palaeozoic subduction system. The Middle Palaeozoic subduction and accretion events mark the evolutionary history along an active convergent margin between the Indochina and South China blocks, possibly related to the amalgamation of the Pangaea supercontinent. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

安徽马鞍山高村采场矿坑地下水疏干预测     

李蛟  朱清山  朱国荣 《江苏地质》2014,38(1):47-52

根据马鞍山高村铁矿露天采场矿区地质及水文地质特征,对矿区的基岩裂隙地下水系统进行概化。结合高村采矿场历史疏干资料和观测孔的地下水动态观测资料,建立了矿区地下水水流模型。然后按照露天采场的开采计划,论证矿坑地下水疏干对策,分别对2个开采规划期进行地下水疏干预测,为安全开采和经济有效地防治地下水提供设计依据。  相似文献   

华北克拉通中元古界底界年龄与盆地性质讨论   总被引：14，自引：0，他引：14  

乔秀夫  王彦斌 《地质学报》2014,88(9):1623-1637

国际地层委员会将中元古界底界界线年龄定为1600Ma,1600~1400Ma为Calymmian(盖层系),表示全球地台盖层形成时期。华北地台基底固结时间为1800Ma,固结后即进入伸展裂解作用时期,首先是山西吕梁山区、晋南中条山、豫西熊耳山区裂解发展成三叉裂陷槽(Aulacogen)。吕梁山区小两岭组火山岩形成年龄有1778±20Ma(SHRIMP U-Pb锆石)及1779±20Ma(LA-ICP-MS U-Pb锆石)两个数值;豫西熊耳群顶部马家河组和中部鸡蛋坪组及下部许山组火山岩年龄分别为1776±20Ma、1791±20Ma和1783±13Ma(SHRIMP U-Pb锆石),1776~1800Ma为火山岩的形成年龄;将1800Ma作为小两岭组与熊耳群两个火山岩组的底界年龄应当是合理的。吕梁山区的汉高山群为碎屑岩夹火山岩,代表吕梁-陕豫三叉裂陷槽北支中的快速充填,与小两岭组为同时期沉积。汉高山群、大古石组(熊耳群底部沉积岩)为1800Ma裂解开始的盖层沉积,小两岭组火山岩、相关的辉绿岩墙及熊耳群火山岩均为裂解时期的岩浆作用产物。北京密云环斑花岗岩侵位时间为1700Ma,代表燕山-太行山裂陷槽裂解的起始时间也即燕山地区长城系常州沟组底界年龄。北京密云地区环斑花岗岩风化壳上覆常州沟组年龄可确定为1650Ma,它不应被看作常州沟组最低层位的年龄,而是裂陷槽裂解后密云地区开始接受沉积的年龄,1700Ma、1650Ma代表常州沟组在不同地区的底界年龄,但均不等于长城系或中元古界的底界年龄。1600Ma为高于庄组底界年龄,即长城系与蓟县系的界线年龄,也是国际地层委员会中元古界的底界年龄。1600Ma代表燕山-太行山裂陷槽闭合的年龄,也是华北地台始自1800Ma伸展裂解作用的最终结束时期。1600Ma是新的陆表海盆地发展的起始时间,是重要的华北地台构造转换的时期。因此,1800与1600Ma代表华北地台重大地质构造事件的年龄,具大区域构造意义,依据对前寒武系界线年龄确定的原则,两个年龄值均可被选择为中元古界底界的界线年龄。但本文赞同中国全国地层委员会采用1800Ma作为中元古界的底界年龄,因其更符合中国的地质构造实际:华北地台裂解-克拉通内裂陷槽中的盖层充填,底界为1800Ma。华北地台中元古界盆地在不同时期,它的构造性质完全不同:1800~1600Ma为裂陷槽;1600~1400Ma发展成陆表海;1400~1300Ma转化为弧后盆地;1800Ma、1600Ma及1400Ma代表中元古代三个重要的区域构造转换的时间点。  相似文献   

川西坳陷中段三叠系雷口坡组—马鞍塘组油气地质条件及有利勘探目标分析   总被引：1，自引：0，他引：1  

许国明  宋晓波  王琼仙 《海相油气地质》2012,(2):14-19

川西地区三叠系发育马鞍塘组滩相裂缝-孔隙型储层、雷口坡组顶部不整合面岩溶缝洞型储层以及雷口坡组台地边缘滩和台内滩相孔隙型储层等多套多种类型的碳酸盐岩储层,油气地质条件良好。认为川西坳陷中段孝新—合丰构造带主要以雷口坡组台内滩、不整合面岩溶储层及马鞍塘组滩相储层为主要勘探目标层系,其中孝泉、新场构造是近期该构造带最有利的勘探目标。坳陷西缘构造带主要以雷口坡组台缘滩及马鞍塘组浅滩相储层为主要勘探目标层系,圈闭面积较大的安县、鸭子河、大邑构造是该构造带风险勘探的有利目标。坳陷东坡构造带主要以雷口坡组台内滩相及不整合面岩溶储层为目标。  相似文献   

云南腾冲黑空山、马鞍山和打莺山火山粗安岩显微结构特征及其火山学意义   总被引：1，自引：1，他引：0  

于红梅  许建东  林传勇  潘波  赵波  林旭东  万园 《岩石学报》2012,28(4):1205-1216

火山喷发物记录了岩浆的整个活动历史,对火山喷发物的研究可以了解大量的岩浆活动特征信息。本文对腾冲火山区的三座全新世火山——黑空山、马鞍山和打莺山火山熔岩进行了详细的研究,包括熔岩和斑晶的成分、显微结构特征和斑晶的晶体大小分布(CSD)分析。研究发现,黑空山、马鞍山和打莺山火山熔岩以粗安岩为主,三座火山粗安岩中的斑晶成分范围接近,但它们的显微结构特征具有一定的差异,反映了不同的岩浆环境,推测来自不同的岩浆囊。黑空山粗安岩中斜长石斑晶的CSD曲线呈微上凹形,反映了小规模的岩浆混合作用。马鞍山和打莺山粗安岩的微斑晶CSD曲线呈很好的线性关系,说明微斑晶形成时的环境相对稳定,推测这些微斑晶是在岩浆上升过程中,停留在地壳的某处并形成一个小型的岩浆囊后受围岩的冷却作用形成。根据以上的分析,认为腾冲火山区下在横向和纵向上均至少存在两个岩浆囊。  相似文献   

Late Holocene record of environmental changes,cyclones and tsunamis in a coastal lake,Mangaia, Cook Islands          下载免费PDF全文

Catherine Chagué‐Goff  Jordan Chi Hang Chan  James Goff  Patricia Gadd 《Island Arc》2016,25(5):333-349

A 4.3 m‐long peat sequence from the shore of Lake Tiriara, Mangaia, Cook Islands, was analyzed using an ITRAX core scanner equipped with a magnetic susceptibility meter. Variations in the elemental profiles, providing insights into long‐ and short‐term environmental changes over the last 3500 years, are supported by grain size data and diatom assemblages. The scattering ratio (Mo Inc/Mo Coh) was evaluated and found to represent a good proxy for organic matter in peat. X‐Ray Fluorescence (XRF) data were processed by principal component analysis that confirmed the distinction of biogenic and detrital phases, organic matter and elements of marine origin. The record preserved in the peat sequence includes a peatland infilling stage followed by alternating drier and wetter periods. A notable steady increase in clay associated with high counts of detrital elements from 2000–1700 cal yr BP is attributed to increased erosion, which is most probably linked with human colonization and/or more intense chemical weathering linked with a wetter climate. Freshwater gastropods (Melanoides sp.), which were possibly introduced by humans, or are native, occupied the wetland during a period of lower water level about 1000–1100 cal yr BP. Short‐term changes in the elemental profiles are often linked with slight coarsening of the inorganic fraction that is, however, only revealed after grain size analysis. Peaks in marine indicators (Br, Cl, S, and/or Ca) associated with marine‐dominated diatom assemblages most probably represent marine incursions through the underground tunnel in the makatea, a fossilized, uplifted coral limestone rim. While none of the marine event units present characteristics typical of cyclone or tsunami deposits, the concurrent or absent peak of detrital elements (Fe, Si, Rb, Ti, K) attributed to increased erosion of the volcanic cone associated with a cyclone is used to distinguish both types of events, as also suggested by principal component analysis.  相似文献   

Tsunami deposit associated with the 2011 Tohoku‐oki tsunami in the Hasunuma site of the Kujukuri coastal plain,Japan          下载免费PDF全文

Dan Matsumoto  Yuki Sawai  Koichiro Tanigawa  Osamu Fujiwara  Yuichi Namegaya  Masanobu Shishikura  Kyoko Kagohara  Haruo Kimura 《Island Arc》2016,25(5):369-385

We describe the detailed sedimentary characteristics of a tsunami deposit associated with the 2011 Tohoku‐oki tsunami in Hasunuma, a site on the Kujukuri coastal plain, Japan. The thick tsunami deposit was limited to within 350 m from the coastline whereas the inundation area extended about 1 km from the coastline. The tsunami deposit was sampled by excavation at 29 locations along three transects and studied using peels, soft‐X imaging and grain‐size analysis. The deposit covers the pre‐existing soil and reached a maximum measured thickness of 35 cm. It consists mainly of well‐sorted medium to fine sand. On the basis of sedimentary structures and changes in grain size, we divided the tsunami deposit into several sedimentary units, which may correspond to multiple inundation flows. The numbers of units and their sedimentary features vary among the three transects, despite the similar topography. This variation implies a considerable influence of local effects such as elevation, vegetation, microtopography, and distance from footpaths, on the tsunami‐related sedimentation.  相似文献   

黄海西部2005—2007年海雾演变的气候特征研究   总被引：2，自引：0，他引：2  

王绪翔  邵利民  曹祥村 《海洋预报》2012,29(3):62-68

海雾对沿海地区的交通运输、工农业生产等影响很大,需要开展深入研究,以探索其生消演变规律。本文选择黄海西部的成山头、青岛、海阳、日照等4个测站为代表性测站,分析了2005—2007年海雾发生期间的位势高度、海温、海表面风场、相对湿度、稳定度及散度等要素场特征,着重探讨了海雾演变的气候特征。研究结果表明:500 hPa高空槽前位于黄海上空时有利于成雾;海温异常低的年份雾日较多;风向、散度和低层的层结稳定度是影响黄海海雾的主要因素;地理位置也是影响黄海海雾变化的重要因子;黄海海雾的水平分布具有南北空间不一致的特点。  相似文献