Summer light‐trap catches of adult Trichoptera in hill‐country catchments of contrasting land use,Waikato, New Zealand

The distribution of adult Trichoptera in light traps was investigated alongside nine streams draining catchments under native forest, pine forest, or pasture near Hamilton, Waikato, New Zealand. The aim of the study was to determine the relationship between abundance, taxonomic richness, and community composition with respect to land use during summer, and to evaluate the use of adult Trichoptera compared with benthic invertebrates as potential bio‐indicators of the effectiveness of land‐management changes. Adult Trichoptera faunas alongside the native streams were dominated by Hydrobiosidae, Conoesucidae, and Helicopsychidae (each >10% of total Trichoptera numbers for at least two of the three sites), whereas Leptoceridae, Oeconescidae, and Hydrobiosidae were relatively abundant alongside at least two of the pine sites. Adult Trichoptera faunas at the pasture sites were strongly dominated by Hydroptilidae which made up 47–85% of numbers caught at all sites. The mean number of individuals and taxa caught in light traps increased from November to January and then declined in February for all land‐use types. Overall, total numbers and taxonomic richness of adult Trichoptera were significantly lower at the pine sites compared to the pasture or native sites. TWINSPAN classification of benthic invertebrates collected in November clearly differentiated sites based on land use for presence/absence and percentage abundance data. A similar pattern was evident for most sites when adult Trichoptera faunas were used for the four sampling dates combined, suggesting that light trapping has potential as a tool for bio‐monitoring.     

鄂尔多斯盆地吴堡地区长6段浊积特征及其石油地质意义

在介绍鄂尔多斯盆地吴堡地区延长组长6段沉积特征的基础上,探讨了该储层物性特征、浊积岩特征、浊积岩分布规律及其对油藏的影响,明确了浊流沉积的石油地质意义.结果表明:鄂尔多斯盆地吴堡地区长6段以发育长石砂岩为主,填隙物成分有方解石、绿泥石、白云母以及少量的石英加大、长石加大等,砂岩储集层孔隙结构具有很强的非均质性;吴堡地区长6期湖盆沉降趋于稳定,是三角洲的高建设时期;多水系、多物源的三角洲前缘沉积为深湖浊积扇沉积提供了充足的物质基础;在吴堡地区东北部三角洲前缘水下分流河道前端发育深湖浊积扇沉积,可区分出中心微相和边缘微相两个沉积微相带,其中浊积扇中心微相以细砂岩、粉砂岩与暗色泥岩呈砂泥互层;从平面上看,浊积岩砂体非均质性在侧向上逐渐变弱,砂体底部发育厚度较大、成熟度较高的暗色湖相沉积的烃源岩,深湖相的暗色泥岩含有丰富的烃源岩,而浊积岩砂体是由深湖相的暗色泥岩构成,孔渗物性好的区域易于形成良好的上倾尖灭的透镜状岩性油藏.     

大庆长垣南部浅层气成因及成藏机制

大庆长垣南部浅层气主要为来源于嫩江组一二段的生物气, 混入少量的青山口组热成因气和无机成因的CO₂.明水组沉积末期为嫩江组一二段大量生排生物气时期, 此时断裂活动导致黑帝庙油层背斜和断圈的形成, 并诱导生物气垂向运移, "三期复合"使大量生物气向黑帝庙油层运移.活动断层均为"断裂密集带"的边界断层, 沿其垂向运移的生物气聚集的部位取决于断层与两盘地层的配置关系, 与断层倾向相反的一盘是生物气聚集的主要部位, 大庆长垣南部总体为"西缓东陡"的不对称背斜, 生物气主要富集在断裂密集带东部边界的圈闭中.黑帝庙油层纵向上分为5套储盖组合, 下部3套组合盖层厚度较大, 受断层错断的概率较小, 是主要的目的层.黑帝庙油层大部分圈闭为"断圈", 断层侧向封闭性决定圈闭的潜力, 断层侧向封闭所需SGR低限为0.375, 利用Allan图解标定断层侧向封闭性并分析圈闭的潜力, 与不考虑断层侧向封闭性时圈闭有3种变化: 一是断层侧向封闭, 面积和幅度没有改变的圈闭(Ⅰ型); 二是断层侧向封闭具有分段性, 面积和幅度变小的圈闭(Ⅱ型); 三是断层侧向不封闭, 不存在的圈闭(Ⅲ型).其中Ⅰ和Ⅱ型圈闭是生物气聚集的有利目标.从大庆长垣南部看松辽盆地浅层气成藏关键因素是有沟通气源的断层控制的圈闭的完整性(背斜或断层侧向封闭性较好的断圈)和区域稳定分布的盖层.      

东海盆地西湖凹陷构造样式及其演化

西湖凹陷是经历多期构造作用的白垩—第三纪盆地。多期裂陷和反转构造作用的叠加导致了相对复杂的构造格架样式和盆地地质结构。凹陷总体上具有东西分带,南北分块的构造格局。裂陷期的同沉积断裂组成了多种复合的构造样式：西部斜坡带主要发育断阶、地堑和地垒构造;中央洼陷带则以复合“Y”字型、羽状和似花状断裂组合为主;东缘断阶带主要发育“Y”字型、梳状和羽状组合。坳陷反转期,早期的同沉积断裂发生了不同程度的逆冲反转,形成了多种复合的构造样式,例如反冲叠瓦扇构造、后断叠瓦式逆冲构造等叠合构造样式。从盆地的构造样式出发,探讨了盆地的形成演化和构造- 沉积充填过程对有利圈闭带发育分布的控制作用,对富生烃凹陷油气预测具有重要指导意义。     

渤海湾盆地南堡凹陷断层对油气运聚的控制作用

在对南堡凹陷断层类型划分的基础上,利用地质统计法和地化分析等技术手段,从宏观到微观多个方面阐述了南堡凹陷断层对油气运聚的控制作用。根据断层的发育历史,将南堡凹陷断层划分为3类：长期活动型(Ⅰ类)、早期活动型(Ⅱ类)和晚期活动型(Ⅲ类)。其中Ⅰ类断层大多沟通油源,是油气纵向运移的主要通道,由于其多期活动,形成了南堡凹陷多套含油层系纵向上相互叠置的局面。断层活动的时期和强度控制油气纵向上的分配,而且油气在平面上主要分布在油源断层附近的断块圈闭中。断层封闭性在时间上具有明显的差异性,在油气运聚过程中扮演输导和封堵双重角色。反向遮挡断层圈闭无论在油气藏数量还是在烃柱高度方面均明显好于顺向断层遮挡圈闭,是南堡凹陷油气勘探的有利目标。断层遮挡圈闭的储量规模受断层封闭性影响,准确评价遮挡断层的封闭能力对于提高钻探成功率具有重要意义。     

饶阳凹陷马西地区古近系层序地层与隐蔽油气藏勘探

利用地震、测井、岩相等资料,对饶阳凹陷马西地区古近系进行了层序地层学研究,将其划分为3个二级层序和10个三级层序。层序Ⅷ、Ⅸ、Ⅹ为河流层序,可划分为基准面上升体系域和基准面下降体系域;层序Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ、Ⅵ和Ⅶ为湖泊层序,每个层序可划分为低位体系域、湖侵体系域和高位体系域。在层序地层研究的基础上,认为马西地区同沉积构造坡折带的存在控制了砂体的展布、烃源岩的发育以及油气的运聚,因而对该地区隐蔽油气藏的形成起控制作用。建立了隐蔽油气藏在不同体系域中的发育模式,并提出了下一步勘探的有利方向。     

Use of camera traps to determine dispersal of tigers in semi-arid landscape,western India

Dispersal is a life history trait that plays a key role in population dynamics. We used camera traps to estimate the distance male and female tigers (Panthera tigris) dispersed from Ranthambhore Tiger Reserve (RTR) in semi-arid habitats of western India from 2003 to 2010. We deployed camera traps whenever tiger tracks were found in places adjacent to protected areas where tigers had not been recently reported. We identified tigers by matching strip patterns by using their photographs with the database of camera-trapped tigers of RTR at the Wildlife Institute of India, Dehradun. We determined the aerial distance (straight line) between the last location of photo-capture in the natal area (in RTR) and the location of the most recent photo-capture. One female and three male tigers that dispersed from RTR were identified from photographs. The longest distance dispersed by a tiger was 148.4 km, and the average dispersed distance was 124.2 ± 23.7 km (n = 3) for male tigers and 78.4 km for the female tiger. The minimum age of the male tigers when they dispersed was 24 months. These data are important for making conservation and management decisions for restoration of potential connectivity between landscapes.     

加蓬海岸盆地南、北次盆成藏特征对比

加蓬海岸盆地属于被动大陆边缘盆地。盆地沉积盖层主要由白垩系、古近系和新近系组成,沉积地层组合具有明显的三分性,包括早白垩世盐下层系、早白垩世晚期阿普特期盐膏层和晚白垩世至新近纪盐上层系。根据目前的油气发现,北加蓬主要富集盐上油气资源,南加蓬主要富集盐下油气资源。从构造沉积背景、油气地质条件、油气发现规模、油气平面分布、油气勘探潜力5方面对南、北次盆进行对比,分析南、北次盆的油气聚集差异,结合勘探现状分析其勘探潜力,并指出南加蓬次盆勘探难点为圈闭识别,北加蓬次盆的勘探难点是砂体预测。     

鄂尔多斯盆地靖边气田J井区储层小幅度构造研究

鄂尔多斯盆地靖边气田现今构造面貌为一区域性西倾大单斜,其下古生界奥陶系主力气层为马五段马五31小层,该小层顶面构造是在极其平缓的构造背景上发育的小幅度褶皱,且局部小幅度构造与产能关系密切,是寻找高产区的有利指向。应用地震解释成果和测井、钻井资料,研究J井区主力气层马五31顶面的小幅度构造分布特征;分析马五31顶面与本溪组9号煤顶、马家沟组标志层(K1、K2)构造的相关性;总结鼻状构造的组合类型;研究鼻隆构造与天然气富集的关系;总结构造圈闭与复合圈闭类型;分析小幅度构造成因动力学特征。这些认识对该井区井位部署、扩边挖潜及水平井动态调整,提高气田开发钻井成功率有着重要的现实意义。     

2005-2006年大亚湾大鹏澳养殖区甲藻孢囊通量的沉积捕捉器研究

于2005年3月至2006年4月在大亚湾的大鹏澳养殖区采用沉积物捕捉器,对甲藻孢囊形成和水温、盐度、营养盐含量等环境因子进行了周年调查,探索该区孢囊形成特征及其与环境因子的关系.在一年的沉积物捕捉器研究中,共分析鉴定出27种甲藻孢囊类型,锥状斯氏藻Scrippsiella trochoidea孢囊为该区最优势孢囊类群,从孢囊的组成显示了该区的污染是以养殖和生活污染为主.孢囊形成没有明显的季节分布特征,两个站年平均为1.07×10<'5>cysts·(m<'2>·d)<'-1>.高、低温都能在一定程度上促进孢囊的生成,氮限制对孢囊的形成具有明显促进作用.首次发现亚历山大藻Alexandrium孢囊在冬季形成的高峰,最高值达4.26×10<'5>cysts·(m<'2>·d)<'-1>.这说明核电站温排水冬季高水温对大亚湾生态环境有较大的影响.