沉积盆地地热史模拟方法及简要述评

沉积盆地的地热史模拟是目前盆地动态模拟的重要内容.盆地热史研究经历了定性、半定量及定量研究的过程,而且这一研究仍在继续深入.目前,盆地热史反演研究占据了主导地位.对目前一些常用的盆地地热史研究方法和手段作概要总结,并加以简要的评述,尤其着重介绍了近年发展起来的地热史反演方法——利用有机质镜质体反射率R_0资料和磷灰石裂变径迹资料反演沉积盆地的地热历史.     

河南小秦岭金矿区方铅矿的远红外反射光谱

以天然形成的方铅矿晶体为研究对象,说明方铅矿远红外反射光谱中低频端Plasmon反射边产生的物理原因,并根据不同反射边的斜率(Va)值大小与样品中所含杂质量的相关性,以解释不同样品中不同组分和结构上的特点对Plasmon反射边的影响。且根据不同杂质的正负相关性在自然成因上的因果关系,证明从反射光诸结构中获得对矿物成因有一定指导意义的信息的可行性。     

Structural modifications of vitrinite and alginite concentrates during pyrolitic maturation at different heating rates. A combined infrared, C NMR and microscopical study

Immature vitrinite samples from a Miocene lignite seam of western Germany (H/C = 1.14, O/C = 0.41) and alginite concentrates from a Tasmanite deposit of Australia (H/C = 1.60, O/C = 0.10) were pyrolyzed in a stream of argon at heating rates of 0.1 and 2.0°C/min up to temperatures varying from 200 to 670°C. The solid maceral residues were subjected to elemental and microscopical analysis and studied by IR and ¹³C CP/MAS NMR spectroscopy with respect to structural modifications.The maximum pyrolytic weight loss amounts to 60% of the initial organic matter in the case of vitrinite and to 85% for alginite, the onset of degradation reactions being shifted to higher temperatures with increasing rate of heating. Both infrared and NMR spectra of the vitrinite samples indicate a rapid decomposition of the cellulose component upon heating whereas lignin related structures such as aromatic ether linkages remain remarkably stable. The main hydrocarbon release from vitrinite occurs at very early evolution stages (T_max = 296°C, R_m = 0.20% at 0.1°C/min; T_max = 337°C, R_m = 0.23 at 2.0°C/min). Hydrocarbon generation from alginite requires higher temperatures (T_max = 388 and 438°C) and is completed within a distinctly narrower temperature range.The pronounced increase of vitrinite reflectance between 350 and 670°C seems to be associated with a rather time-consuming reorganization of the residual organic material. The concomitant growth of polyaromatic units is illustrated by the increasing intensity ratio of the aromatic ring stretching vibration bands at 1600 and 1500 cm⁻¹. These reactions are moreover marked by increasing loss of phenolic oxygen and by increasing conversion of aliphatic carbon into fixed aromatic carbon.     

Mineralogy and organic petrology of oil shales in the Sangkarewang Formation, Ombilin Basin, West Sumatra, Indonesia

The Ombilin Basin is filled by late Eocene to early Oligocene marginal fan deposits (Brani Formation) and lacustrine shales (Sangkarewang Formation), unconformably overlain by a late Oligocene to early Miocene fluvial sequence (Sawahlunto and Sawahtambang Formations) and capped by an early to mid-Miocene marine sequence (Ombilin Formation). Significant oil shale deposits occur in the Sangkarewang Formation, intercalated with thin laminated greenish-grey calcareous sandstones. X-ray diffraction shows that the sediments consist mainly of quartz, feldspar, carbonates and a range of clay minerals, together in some cases with minor proportions of sulphides, evaporites and zeolites. Feldspar and non-kaolinite clay minerals decrease up the sequence, relative to kaolinite, suggesting a changing sediment source as the basin was filled. Calcite, thought to be mainly of authigenic origin, is also more abundant in the middle and upper parts of the sequence.The organic matter in the oil shales of the sequence is dominated by liptinite macerals, particularly alginite (mainly lamalginite) and sporinite. Cutinite also occurs in some samples, along with resinite and traces of bituminite. The dominance of lamalginite in the liptinite components suggests that the material can be described as a lamosite. Samples from the Sangkarewang Formation have vitrinite reflectance values ranging between 0.37% and 0.55%. These are markedly lower than the vitrinite reflectance for coal from the overlying Sawahlunto Formation (0.68%), possibly due to suppression associated with the abundant liptinite in the oil shales.Fischer assay data on outcrop samples indicate that the oil yield is related to the organic carbon content. Correlations with XRD data show that, with one exception, the oil yield and organic carbon can also be correlated directly to the abundance of carbonate (calcite) and inversely to the abundance of quartz plus feldspar. This suggests that the abundance of algal material in the lake sediments was preferentially associated with carbonate deposition. High yields of oil are noted in some samples, as a percentage of the organic carbon content. This may indicate that partial generation of hydrocarbons from the material has already taken place, in association with thermal maturation of the Sangkarewang succession.     

湘中涟源凹陷镜质体反射率与地层剥蚀厚度恢复

为了计算涟源凹陷的剥蚀量,恢复其构造演化,采用了涟源凹陷各地层平均镜质体反射率和刘家塘组的.Ro值分析了涟源凹陷的平面展布.结果表明,涟源凹陷在中晚泥盆世的沉降速度最快;晚泥盆世-石炭纪沉降速度相对减慢;在二叠纪-三叠纪沉降速度进一步减慢;在早三叠世晚期涟源凹陷发生了大面积的抬升,并伴随有东南-西北向的强烈挤压,出现角度不整合;晚三叠世时地层重新开始沉积.区内地层是不均匀抬升,凹陷边缘较凹陷内部抬升量大;在凹陷内部,背斜区地层破坏极为严重.     

四川会理-会东地区火山沉积变质型铜矿遥感地质特征及找矿标志

通过遥感地质构造特征解译,结合地质分析,对两会地区火山-沉积变质型铜矿的成矿争件,矿床地质特征及控矿因素进行了研究,将矿床类型细分为火山沉积变质型（拉拉式）、沉积变质型（大箐式,相当于东川式）、火山沉积热液改造型（小青山式）三种亚型,分别提出了各亚型铜矿的遥感找矿标志。     

卫星对地遥感应用中的邻近效应研究

利用Monte-Carlo地气耦合辐射传输模式比较系统地进行了卫星视反射率对地表、大气和卫星参数的敏感性数值试验,重点研究了邻近效应对地表反射水平非均一分布的敏感性、邻近效应有效地表范围以及邻近效应与卫星高度的关系三个方面的问题.在定量分析的基础上,揭示了影响邻近效应的主要因子及其影响机制,给出了一些重要结论,包括:地表非均一引起的邻近效应的影响是非常重要的,特别是当目标反射率小于环境反射率时;气溶胶光学厚度越大,散射相函数对称性越强,卫星视反射率对环境反射率越敏趑感,邻近效应越明显;邻近效应的有效地表范围可达到几十公里,同样光学厚度条件下,与气溶胶相比,分子的有效地表范围更大,邻近效应也更强;卫星观测同一目标物时,邻近效应随着探测器高度增高而变大等.     

贝尔凹陷布达特群垂直裂缝垂向封闭性演化特征

通过岩心观察和成像测井资料分析,发现贝尔凹陷布达特群垂直裂缝较发育,其形成与分布受断裂控制。利用SiO₂或CaCO₃沉淀胶结所需要的镜质体反射率值,对贝尔凹陷布达特群垂直裂缝目前垂向封闭性进行了评价。凹陷大部分地区开启,仅在凹陷少部分地区封闭,封闭区在凹陷中部呈环带分布,在凹陷边部呈条带分布。贝尔凹陷布达特群垂直裂缝现今垂向封闭性差于地质历史时期垂向封闭性,油气保存条件变差,造成油气大量散失,这可能是目前贝尔凹陷能在布达特群找到一批油气藏的重要原因之一。     

基于D-S理论的卫星遥感海表面温度和同化数据融合方法

利用卫星遥感获取海表面温度实时性强,但其数据质量随大气环境而波动;利用同化技术求解的海表面温度局部精度高,但覆盖面与实时性差.鉴于两种技术适应不同情况,拟使用信息融合技术实现两者优势互补,即根据各自的优势和局限性对数据点进行一致性评价和加权融合计算,在提高精度的同时对结果的不确定性进行量化和评价.以我国东部海域海表温度为例的采样试验结果表明,融合法更适应复杂的环境.