北美地质演化与钾盐成矿

北美大陆拥有世界上最大的钾盐矿床,北美大陆的钾盐储量占全球已探明钾盐储量的一半数。本文在总结北美大陆地质构造单元划分、地质演化历史的基础上,重点分析了晚古生代地台沉积序列及其与钾盐矿床形成的关系,指出钾盐主要形成于欠补偿的海相地台型盆地,个别形成于海陆交互相的克拉通边缘地堑/裂谷盆地中;钾盐层主要位于海相台地序列的最后一个旋廻(Kaskaskia序列),以及从台地向前陆盆地转化的过渡阶段(Absaroka序列),当海相台地转化为前陆盆地之后,就不再有钾盐矿床的形成。北美晚古生代钾盐大规模集中成矿作用,也与该时期北美大陆古赤道位置密切相关。钾盐矿床的形成是构造-盆地-古气候等多种因素耦合的结果,钾盐找矿是有章可循的。     

兰村煤矿沉积体系特征及其对含煤性的控制

攸县兰村煤矿区晚二叠世的充填沉积，可划分为滨海粉砂淤泥盆地、海湾泻湖、三角洲、障壁坝－泻湖及浅海钙泥质台地等５个沉积体系。本文分析了海进海退旋回对沉积体系含煤性的控制。     

从地质特征分析成都主城区在地震中的安合性

汶川MS 8.0大地震发生后,关于成都市主城区安全性的讨论一度十分激烈。本文从成都市及周边的基本地质构造和沉积特征入手,讨论成都市主城区在地震中的安全性问题。经过分析认为：川西坳陷刚性稳定的岩石圈结构决定了成都平原不会发生破坏性的大地震; 成都平原沉积盖层厚度大、质量佳、分布适宜决定了龙门山发生的地震不会对成都主城区造成巨大破坏。因此,面对天然地震,成都市主城区是安全的。     

贵州安顺旧州晚二叠世龙潭期沉积特征及地质意义

本文通过安顺旧州地区地面调查及钻孔岩性分析研究,从岩性组合、沉积构造、沉积相特征、沉积模式分析,进一步说明该区处于晚二叠世三岔河地区龙潭相区与吴家坪相区的相变位置,属于潮坪—泻湖相至半局限台地相过渡带,是具有特殊组成含义的龙潭组。由此推断晚二叠世龙潭期相变线(带)应为由北(遵义)向南延伸至贵阳后经林歹—平坝—天龙—旧州(研究区)一线向南西延伸到兴义,北西为龙潭相区,南东为吴家坪相区。     

Determination of sedimentary cover and structural trends in the Central Sinai area using gravity and magnetic data analysis

The present study is an attempt to determine the sedimentary cover, and structural trends in the central part of Sinai Peninsula, Egypt. This study has been implemented by the integration of gravity and magnetic methods. Gravity data has been used for 2D modelling along some profiles perpendicular to the main structural trends of the study area. Magnetic data will be analyzed to determine the depth to the basement surface. The depths obtained from magnetic data will be used as a control points in the gravity modelling in order to minimize the error and facilitate the iteration of the suggested models. The basement relief map from magnetic and gravity output has been produced. This map indicates that, the basement depths, generally, increases from south to north and from east to west direction of the study area. The sedimentary cover is about 1.5-2 km in the southern part and increases to more than 4 km in the northeastern and western parts and changes gradually in the other parts of the study area. Results of structural trend analysis indicate that, the study area is greatly affected by several structural trends; N-S, E-W, NW-SE, and NNE-SSW directions. These trends are associated with the Baltim fault trend, Tethyan trend, Gulf of Suez, and Aqaba trend, respectively.     

试论海相碳酸盐岩储层发育的影响因素：以任丘油田雾迷山组为例

依据任丘潜山碳酸盐岩储层研究成果及潜山油藏有关储层资料,分析了海相碳酸盐岩储层发育的影响因素。储层中泥质白云岩与粗结构藻白去岩的韵律性的岩性剖面,纵向上储层与非储层交替出现,孔洞的发育顺层分布,形成同层渗透带;多次沉积间断,构成多岩溶期,并有沿风化壳的溶蚀缝洞带及古水平岩溶带;构造应力产生断层和构造缝发育带,可形成断裂高渗带;成岩后生作用及储层演化,经历了各种次生改造,形成现今的储层面貌。认为层位     

东准卡姆斯特地区中侏罗—渐新世古气候环境分析及对砂岩型铀矿的影响

砂岩型铀矿属沉积盆地内表生水渗入成矿类型,古气候条件、沉积环境对含矿建造的形成、后生改造及铀元素的富集成矿等具重要影响。本次研究主要对该区内多个钻孔不同层位、不同颜色岩石系统采样测试,据测试结果对卡姆斯特地区不同地质时期岩石地球化学特征及古气候条件、沉积环境进行研究,并探讨古气候条件对该区铀元素迁移富集的影响。本次共采取234件侏罗—新近系岩石样品,开展常、微量元素分析、有机碳含量分析及粘土矿物相对含量分析。结果表明,从中侏罗世西山窑期至古近纪中晚期研究区气候总体为温湿-干旱,中侏罗世头屯河期早期沿袭了温湿气候,后期逐渐向干旱转变,为一个气候过渡期,有利于卡姆斯特地区与氧化带相关铀成矿作用的发育。     

Description of a new toothed mysticete from the Late Oligocene of San Juan de La Costa,B.C.S., México

This paper describes a toothed mysticete that belongs to a basal family found in Oligocene sedimentary rocks deposited in the North Pacific Ocean. The material that is described here belongs in the Chattian stage of the Oligocene, and it was collected near Arroyo El Saladito from the San Juan Member in the El Cien Formation, Baja California Sur, México. The sedimentary environment of this area has been interpreted to be a continental platform with nutrient-rich waters combined with anoxic conditions. Therefore, the specimens that have been found in the phosphorite layers lived in an environment of shallow coastal waters. The material described is a dentary fragment, a skull and fragments of the teeth. The new taxon is located within the Superfamily Aetiocetoidea due to the presence of functional teeth, which have a slightly globose shape with eight slightly triangular apices. Niparajacetus palmadentis presents a morphology that contrasts with other toothed whales. For example, it shows an elongated and wide skull in the posterior region with a triangular shape, and its estimated total length is 3.2–3.5 m.     

哀牢山造山带构造演化及其两侧盆地耦合

哀牢山造山带的崛起和盆地耦合,对东西两侧沉降盆地的构造-沉积性质起关键性作用。转换构造性质不仅形成了逆冲推覆与走滑剪切联合作用的构造共生组合,形成两类不同性质的沉积盆地。     

江苏海岸潮滩沉积环境及其可持续利用问题

凭借着独一无二的地质、地貌、海洋、气候、土壤和生态特征，江苏潮滩拥有丰富的自然资源，然而却又受着不利自然条件及不合理人类活动的限制。江苏潮滩沉积表现出4个水平相带：草滩(湿地)沉积带、盐蒿泥滩沉积带、泥一砂混和滩沉积带、粉砂滩沉积带。潮滩是极为脆弱的生态系统，它极容易受到湿地围垦、低效的生产方式、酷取滥采、环境污染等人类扰动的破坏。基于以上认识，提出顺应潮滩自然演变，人类活动与潮滩沉积环境的和谐开发利用及保护模式。