中高山区高精度航磁调查找矿效果研究

随着矿产资源需求的不断加大,我国西部高山区利用高精度航磁技术开展矿产勘查的需求越来越高,本文以东昆仑、阿尔金等多个高山区实测资料为基础,通过对不同型号飞机性能进行对比,选择适合高山区航磁测量的飞行平台;结合理论模型计算与不同高度飞行试验,确定了高山区有效飞行高度;并在基础上开展了航地磁测量效果对比.在航磁资料精细解释方面尝试了曲面位场转换处理,对比了转换前后局部异常强度变化;针对高海拔地区弱小磁异常选编,开展了弱缓异常提取技术研究;并针对起伏地形条件下航磁异常2.5D/3D精细反演解释技术手段进行了尝试,就如何提高航磁资料找矿效果进行了积极的探索.     

偏移速度分析与速度反演方法评述

本文阐述了各向同性介质中纵波偏移速度建模中的速度分析方法原理及其优缺点,包括常规速度分析、偏移速度分析、层析偏移速度分析以及全波形反演。其中着重阐述了深度域速度建模中的速度分析方法原理及其在实用中的优缺点。最后对深度域偏移速度分析方法进行了展望。     

Spatial coupling relationships of gas hydrate formation in the Tibetan Plateau

At present, gas hydrates are known to occur in continental high latitude permafrost regions and deep sea sediments. For middle latitude permafrost regions of the Tibetan Plateau, further research is required to ascertain its potential development of gas hydrates. This paper reviewed pertinent literature on gas hydrates in the Tibetan Plateau. Both geological and ge- ographical data are synthesized to reveal the relationship between gas hydrate formation and petroleum geological evo- lution, Plateau uplift, formation of permafrost, and glacial processes. Previous studies indicate that numerous residual basins in the Plateau have been formed by original sedimentary basins accompanied by rapid uplift of the Plateau. Ex- tensive marine Mesozoic hydrocarbon source rocks in these basins could provide rich sources of materials forming gas hydrates in permafrost. Primary hydrocarbon-generating period in the Plateau is from late Jurassic to early Cretaceous, while secondary hydrocarbon generation, regionally or locally, occurs mainly in the Paleogene. Before rapid uplift of the Plateau, oil-gas reservoirs were continuously destroyed and assembled to form new reservoirs due to structural and thermal dynamics, forcing hydrocarbon migration. Since 3.4 Ma B.P., the Plateau has undergone strong uplift and extensive gla- ciation, periglacier processes prevailed, hydrocarbon gas again migrated, and free gas beneath ice sheets within sedi- mentary materials interacted with water, generating gas hydrates which were finally preserved under a cap formed by frozen layers through rapid cooling in the Plateau. Taken as a whole, it can be safely concluded that there is great temporal and spatial coupling relationships between evolution of the Tibetan Plateau and generation of gas hydrates.     

云南通海盆地的浅层速度结构

为了研究通海盆地的地震动场地效应,在强地面运动的数值模拟计算中需要提供该地区的浅层速度结构模型.为此,在通海盆地开展了10 km高分辨率反射地震勘探和30个测点的面波联合勘探工作.综合本次探测结果与褐煤普查中的电测深和钻孔资料,得到了通海盆地的基岩埋深分布图.结果表明,在通海盆地中部,新生界厚度为100~300 m,整体表现出西南厚东北薄的趋势,盆地沉积层厚度变化明显受到小江断裂南段分支断裂的控制.浅层速度随深度分布表现出在深度相同的情况下,盆地边缘的速度高于盆地中部.     

南海北部洋陆转换带盆地发育动力学机制

南海北部洋陆转换带是近年来基础科学研究和深水油气勘探热点地区.本文在详细研究南海北部洋陆转换带新采集的二维长电缆深反射地震剖面资料的基础上,采用挠曲悬臂梁模型和挠曲回剥模型算法,分别计算了上地壳、地壳和整个岩石圈拉伸系数,实验结果表明,研究区洋陆转换带盆地岩石圈发生了与深度相关的拉伸变形过程,并且随深度增加,拉伸量逐渐变大,该结果解释了南海北部盆地裂后阶段发生的加速沉降现象.同时,本文结合南海北部洋陆转换带盆地发育过程的特点,将洋陆转换带盆地演化划分为陆内裂陷阶段、裂后热沉降阶段和裂后加速沉降阶段.本研究将有助于认识南海北部深水盆地特征,并对大陆边缘动力学研究和陆缘盆地深水区油气勘探有重要意义.     

基于逆散射级数法的鬼波压制方法

鬼波问题是影响海上地震资料分辨率和保真度提高的最重要因素之一.详细论述了逆散射级数理论和逆散射级数法鬼波压制原理,说明了逆散射级数方法进行鬼波压制理论的完善性和对鬼波描述的精确性.实现了基于逆散射级数理论的鬼波压制方法,方法以波动方程和Lippmann-Schwinger方程为基础,在频率-波数-波数域内构造与鬼波相关的压制算子,在不需要对地下介质作任何假设条件下实现地震数据驱动鬼波压制,并通过改善消除鬼波的压制算子,提高算法的稳定性.资料处理试验与处理结果分析表明,基于逆散射级数鬼波压制方法能在实现鬼波压制的同时较好保留有效反射波的信息,从而补偿地震资料低频损失和提高地震数据的保真度.数据处理试验还表明,研究方法能对低信噪比的地震资料进行有效的鬼波压制处理.建立了基于逆散射级数鬼波压制处理流程.     

Hypercube-Based Visualization Architecture for Web-Based Environmental Geospatial Information Systems

The geospatial field significantly influences the development of the environmental domain, including a wide range of geospatial and cartographic information systems, such as Geographic Information Systems (GIS), Multimedia Atlas Information Systems (MAIS) and more recently web-based GIS (Web-GIS). In this context, we introduce web-based environmental geospatial information systems (Web-EGIS) as a special case of Web-GIS, aiming to integrate the functionalities of geospatial information systems with the enormous quantity of specialized, distributed and highly heterogeneous environmental geo-referenced data and services. We define three main characteristics of the Web-EGIS. The first is a generic hypercube-based data organization and visualization. The next characteristic is a standard-based, three-tier service-oriented architecture. The third and last characteristic is the traceability of the architectural and design decisions, for which we introduce the new concept of an ‘Environmental Application Context’, arguing that not only the functional but also the non-functional requirements (NFRs) have an important role in defining the architecture, software components and data services of such systems. In a nutshell, a Web-EGIS is characterized by a coherent user experience through the hypercube-based visualization concept, technically supported by a service-oriented architecture that is structured according to an extensive analysis of NFRs. On this basis, we introduce the Geodata visualization and interactive training environment (GeoVITe) Platform for Interdisciplinary Environmental Research as a reference implementation of a Web-EGIS with its basic design requirements, integrative hypercube-based visualization for heterogeneous data sources, extended web cartography functionalities, and its de facto system architecture. The concept of the hypercube-based visualization is better transferred to the system architecture by understanding the ‘Environmental Application Context’ of this particular Web-EGIS, which also makes it easier to maintain and enhance. The resulting system is a support platform for research activities in the environmental domain.     

隐伏构造蚀变岩型钼矿区勘探线布设方法及矿体圈定中有关问题的讨论

建议隐伏矿矿区采用行、排剖面网法布置勘探线和钻孔,利于多方位编制研究性勘探线剖面图,研究和确定深部矿体产状。对隐伏构造蚀变岩型、石英脉—蚀变岩型钼矿333类型资源/储量的圈定与外推分七种情况作了叙述,对米.百分值工程矿体的圈定和外推分五种情况作了叙述。低品位矿应圈定矿体与估算资源/储量。     

方解石脉对中扬子地区沉湖土地堂复向斜油气保存单元的指示意义

野外观测表明,中扬子地区沉湖土地堂复向斜京山县城附近野外露头中二叠系和三叠系方解石脉主要是沿节理缝发育,脉体宽度较小。方解石脉的镜下微观的结晶特征、阴极发光特征、脉体穿插关系可以判断二叠系脉体大约有两期,三叠系脉体大约有三期。碳氧同位素值表明,三叠系方解石脉和围岩的氧同位素差值不大(Δδ18 O的差异范围为-0.19‰～4.12‰,平均值为1.9‰),二叠系方解石脉和围岩氧同位素差异较大(Δδ18 O的差异范围为4.07‰～12.03‰,平均值为7.3‰),三叠系脉体的流体直接来源于围岩,二叠系裂隙中方解石脉的形成过程中可能主要受到有机质的影响。方解石脉体中的流体包裹体均一温度在研究区建立的代表性虚拟井的埋藏史和热史基础上,推测二叠系方解石脉形成深度为3 000m～3 700m,形成深度约为2 000m～3 000m,两套地层中的方解石脉的形成时期为J3—K1燕山构造运动期。中扬子地区在多旋回的沉降和沉积过程中形成的上组合的区域性盖层(中三叠统—下侏罗统的泥质岩)在江汉平原区具有较好的封盖性。     

综合地质-地球物理方法在金矿中的应用

河北省丰宁县坝州营金矿床赋存于五台期侵位的“变闪长岩”中,该区从太古代到中生代长期处于构造隆升剥蚀状态,发育多期岩浆侵位事件,为金矿提供了充分的成矿条件。根据区域地质背景及围岩蚀变、矿化等特征,推断本矿床属于受构造控制的中一低温热液石英脉型金矿。结合矿区地质特征开展地球物理工作,以高密度电法圈定了地下矿化体的范围,辅以音频大地电磁测量,实现探测相对深部断裂构造,并以钻探证实,取得了找矿突破,达到了推断控矿构造的走向和找矿前景等目的。