库车坳陷地质结构及油气带预测

利用油气地震勘探成果和露头的岩性资料 ,对库车坳陷地震层序进行划分 ,初步认为第三系膏盐层和三叠 -侏罗系煤层及泥岩是分布比较稳定的区域性软弱层 ,构成了区域内的主要滑脱面。将库车坳陷划分 6个构造带 ,对库车坳陷的构造样式进行归纳总结 ,并结合典型实例 ,采用平衡地质剖面技术对重要剖面进行地质平衡解译 ,使库车坳陷地质结构更加清晰。结合该区油气成藏的地质条件 ,划分出若干油气聚集带 ,对各油气聚集带进行分别评价     

准噶尔盆地结构及其圈闭类型

准噶尔盆地是复合叠加前陆盆地 ,其原型分别形成于板块俯冲、碰撞、造山带后期复活、拗拉槽回返和板内皱陷作用有关的大地构造环境。其古生代盆地的形成与相邻的阿尔泰山和东、西准噶尔山、天山及博格达山的造山作用相关。中新生代盆地的形成和改造与其南部特提斯域板块俯冲碰撞造山引起的盆地相邻造山带的复活有关。相邻造山带时空上不均一的造山作用对盆地的影响不同 ,形成了盆地独特的结构。各坳陷均由与其形成有关的造山带前缘冲断带、陡坡带、山前凹陷、缓坡带和前隆及前缘皱陷等构成 ,前隆之间的叠加构成了盆地的大型隆起 ,皱陷叠加构成了盆地的中央坳陷。不同类型的圈闭在坳陷中有规律地分布着     

准噶尔含煤盆地构造演化与聚煤作用

准噶尔含煤盆地是新疆主要含煤盆地之一 ,从含煤盆地内各煤田的含煤地层特征 ,构造特征及煤层赋存特征着手 ,分析了盆地内的沉积环境 ,构造演化和聚煤作用 ,论述了两个主要聚煤期所形成的含煤建造的发生、发展过程 ,指出了两个含煤建造中聚煤中心和富煤带的位置     

Characteristics of telemagmatic metamorphism of the Ceshui Formation coal in Lianyuan coal basin

The Ceshui Formation coal is mostly anthracite and its metamorphism has been less documented.By analyzing systematically the reflectance of vitrinite and the results of X-ray diffraction of the Ceshui Formation cola in the Lianyuan coal basin,the spatial variation characteristics of coal ranks,coal metamorphic regions,the extension of coal metamorphic belts.coal metamorphic gradients,coal chemical structure and the effect on the degree of metamorphism of heat-production and -storge conditions,buried depth of the Indosinian-Yenshanian granites at the margins of the Lianyuan coal basin are discussed.The research results in conjunction of the features of regional hydrothermal alterations,endogenetic deposits with the Ceshui Formation coal measures,and the development of secondary vesicles indicate that the telemagmatic metamorphism is the main factor leading to the metamorphism of the Ceshui Formation coal in the region studied.     

Study on fine structure of crust-mantle transition zone in Yanqing-Hailai basin based on CDP and DSS data

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Middle Proterozoic–early Palaeozoic evolution of central Baltoscandian intracratonic basins: evidence for asthenospheric diapirs

The three intracratonic sedimentary basins located in central Baltoscandinavia, namely the Bothnian Gulf basin, the Bothnian Sea basin and the Baltic basin, developed in response to Middle Proterozoic and Late Proterozoic tectonic events, separated in time by about 800 Ma. Only the Baltic basin was subsequently affected by Caledonian orogenesis and Mesozoic rifting. Crustal extension was minor or did not take place during the Proterozoic basin evolution phases. However, according to the Moho topography, crustal thinning did take place. This was probably a result of subcrustal magmatism. On a craton-wide scale, the ages of granitoids, which intruded during the Middle Proterozoic basin formation, generally decrease from east to west. This fact, combined with the evidence provided by mantle-derived flood basalt magmatism, points to a moving asthenospheric diapir as the cause for basin development. Asthenospheric upwelling was probably also responsible for the second, Late Proterozoic, basin evolution phase, as evidenced by the lack of crustal thinning and extension, and the occurrence of tholeiitic intrusions. In addition, a Late Proterozoic thermally induced palaeo-high, located at about the position of the intracratonic basins, is compatible with indications from glaciations. As the ages of Late Proterozoic intracratonic basins also decrease from east to west across the craton, the location of asthenospheric diapirism during this time interval was also moving. For the Fennoscandian lithosphere, the presence of fundamental lithospheric weakness zones (e.g. terrane boundaries) might be an explanation for the formation of two generations of basins originating from asthenospheric upwelling at about the same location in the Fennoscandian Shield. The spacing and size of the Proterozoic intracratonic basins suggest that the asthenospheric diapirism was not deep seated. Therefore, sublithospheric convective processes might be the cause for the asthenospheric upwellings. Such processes are related to Rayleigh–Taylor instabilities in the sublithospheric mantle. Emplacement of an asthenospheric diapir causes a thermal bulge at the surface of the lithosphere. Modelling results demonstrate that erosion of the surficial high, succeeded by cooling of the lithosphere, can explain the accumulation of early Palaeozoic sediments in the Bothnian Sea basin, taking into account post-Ordovician vertical and lateral erosion of the basin fill.     

Sea level,climate change and coastal evolution in Morar,northwest Scotland

Analyses of geomorphologically contrasting sites in Morar, NW Scotland, describe the forcing mechanisms of coastal change. Isolation basins (i.e. basins behind rock sills and now isolated from the sea following isostatic uplift) accumulated continuous marine and freshwater sediments from c.12 to 2 ka BP. Raised dune, marsh and wetland sites register breaching, migration and stability of dunes from c. 9 to 2 ka BP. High-resolution methods designed to address issues of macroscale and microscale sea-level changes and patterns of storminess include 1-mm sampling for pollen, dinocyst and diatom analyses, infra-red photography, X-ray photography and thin-section analysis. The data enhance the record of relative sea-level change for the area. Major phases of landward migration of the coast occurred during the period of low sea-level rise in the mid-Holocene as the rate of rise decreased from c. 3 to < 1 mm/year. Relative sea-level change controls the broad pattern of coastal evolution at each site; local site-specific factors contribute to short-term process change. There is no record of extreme events such as tsunami. Within a system of dynamic metastable equilibrium, the Holocene records show that site-specific factors determine the exact timing of system breakdown, e.g. dune breaching, superimposed on regional sea-level rise. The global average sea-level rise of 3 to 6 mm/yr by AD 2050 predicted by IPCC would only partly be offset in the Morar area by isostatic uplift of about 1 mm/yr. A change from relative sea-level fall to sea-level rise, in areas where the regional rate of uplift no longer offsets global processes, is a critical factor in the management of coastal resources.     

小江断裂带中段晚新生代构造盆地演化阶段

小江断裂带中段的盆地可以划分三个阶段,即Ｎ２－Ｑ１,Ｑ２末－Ｑ３初和Ｑ３－Ｑ４。这些盆地受小江断裂带左旋走滑运动控制。     

Mechanism and Modes of Microbial Minerogenesis of Polymetallic Nodules on the Ocean Floor

This paper presents a quantitative analysis of the relations of the occurrence of polymetallic nodules with the geochemical actions of microbes in the seawater, pore water and sediments at the bottom of the eastern Pacific Ocean basin. Emphasis is laid on the relations of the activity intensity and biochemical transformation rate of aerobic bacteria (iron bacteria, Thiobacillus thioparus, halobacteria and manganese-oxidizing bacteria) and anaerobic bacteria (sulphate-reducing bacteria, denitrifying bacteria, Thiobacillus denitrificans) with mineralization. The experimental research on the migration and accumulation of ore-forming elements caused by microbial and chemical actions shows that the microbes have changed the conditions of oxidation and reduction in the system, and their effect on the element precipitation is much stronger than the chemical actions and accelerates the enrichment of Fe and Mn. It demonstrates that the microbes can change the environment to promote the accumulation of ore-formin     

重庆玉峡锶矿床中分散元素锶的超常富集机制

重庆玉峡锶矿床位于华蓥山构造带的南段。含矿岩系为下三叠统嘉陵江组二段一亚段的含藻含膏白云岩,含矿层位自下而上有三个矿层。矿层呈似层状、透镜状赋存于西山背斜北段的背斜转折端及相邻两翼的层间虚脱部位。矿石矿物有天青石、菱锶矿、钡天青石,脉石矿物为白云石、...