新疆阿依托汉铜矿地质特征及找矿方向

阿依托汉矿区位于阿尔泰山区南缘的阿舍勒Cu-Au-Pb-Zn矿带,共发现5条铜矿体,铜矿体主要赋存于下-中泥盆统阿舍勒组第一岩性段的大理岩和变质凝灰岩中,少量产于石英斑岩脉中;与成矿有关的中泥盆世英云闪长岩和晚期岩脉提供了成矿热源并形成与矿化相关的矽卡岩化、硅化、绢云母化、绿帘石化等围岩蚀变;玛尔卡库里大断裂的次级断裂(F5韧脆性断裂)控制了铜矿体的储矿空间;成矿主要经过了早-中泥盆世(火山-沉积作用)、中泥盆世(岩浆侵入作用)和中-晚泥盆世(铜矿的主矿化阶段)多个阶段,是多种地质因素的耦合导致最终成矿。矿床体现了"层控-岩控-构控-时控"四位一体控矿的特点,不宜用单一的成矿模型予以描述定位,矿床类型属于热液交代-充填型铜矿床。文章在总结找矿标志的基础上,对下一步的找矿方向进行了探讨。     

Characteristics of Ore-controlling Structures and Ore Emplacement Mechanism in the Shihu Gold Deposit,Hebei Province - A Case Study of the No.101 VeinEI北大核心CSCD

The Shihu gold deposit lies in the middle-northern Taihang Mountains and is strictly controlled by faults. The ore-controlling structures in the mining district are not well-documented. Detailed field observation and laboratory investigation of the No.101 vein indicated that the ore-controlling structures of the Shihu gold deposit are the pre-Mesozoic shear joints with SN and NW strike that reactivated during the Yanshanian emerged from. The NNW-SSE left-strike-slip stresses during the main mineralization stage led to the dilation of the NW-strike structural segments along the roof and footwall of the early quartz diorite porphyrite veins, which contributed to the extensive wall-rock alteration, intensive gold mineralization and occur as quartz-vein type ores, and consequently the formation of rich ore pillars. On the contrary, the SN-strike compressive structures correspond to the weak wall-rock alteration and gold mineralization and occur as altered-rock type ores. All the rich ore pillars laterally distributed with high-angle (70°±), and wholly pitched southward with 40° angle. According to the structural ore-controlling regularities, the location between the No.47 and the No.61 exploratory line with elevation below 150 m is an excellent ore-prospecting area. Our prospecting proposal based on the ore-controlling structural analyses in the study area has been proven by the underground works in the Shihu gold deposit. © 2017, Science Press. All right reserved.     

Evolution of the Late Triassic Paleo-uplift in the Southwestern Upper Yangtze Region and its Tectonic SignificanceEI北大核心CSCD

Based on field geological survey and stratigraphic analysis, a Late Triassic Paleo-uplift is identified in the southwestern upper Yangtze region. The tectonic features, evolution history and tectonic significance of this paleo-uplift are discussed in detail in this paper. The results suggest that the hiatus of the Upper Triassic in the southwestern upper Yangtze region was resulted from the paleo-uplift that roughly parallel to the southwest margin of the upper Yangtze region. The formation of the paleo-uplift is related to the closure of the Jinshajiang-Ailaoshan-Songma-Babu and Ganzi-Litang Oceans and their subsequent collisional orogenesis along the southwest margin of the upper Yangtze region. The forebulges of the Youjiang and Chuxiong Foreland Basins were formed by the closure of the Jinshajiang-Ailaoshan-Songma-Babu Ocean, comprising the paleo-uplift at the end of the Early Triassic. Then the forebulge of the Xichang Foreland Basin was developed by the closure of the Ganzi-Litang Ocean in the Norian, and became a new part of the paleo-uplift. Owing to the termination of the Youjiang Foreland Basin at the end of the Rhaetian, the paleo-uplift was composed only of the forebulges of the Chuxiong and Xichang Foreland Basins. The discovery of the paleo-uplift will help us to better understand the prototype of the Sichuan Basin and the tectonic evolution of the southwestern upper Yangtze region during the Late Triassic. © 2017, Science Press. All right reserved.     

川西岷江河谷典型大型—巨型古滑坡特征物探解译分析

在遥感解译、野外调查的基础上,采用高密度电法和电阻率测深法,并结合钻探对川西岷江河谷发育的尕米寺滑坡、俄寨村滑坡、格机寨滑坡等典型大型—巨型古滑坡的空间结构进行了勘探分析,有效确定了古滑坡的空间结构和滑带特征,并认为古滑坡的滑动面多具有高低阻相间的不稳定电性层,且滑坡前缘多位于不稳定电性层变薄收敛的地方。其中,俄寨村滑坡高低阻相间的不稳定电性层厚约0~45 m,为滑坡堆积层,古滑动面紧贴基岩面,滑动面平均埋深约30 m,弱风化基岩面埋深约5.6~61 m,强风化层厚约为3~12 m;尕米寺滑坡高低阻相间的不稳定电性层厚约2.5~43 m,为滑坡堆积层,沿剖面古滑动面平均埋深约35 m,在滑坡中部存在一圈闭的低阻异常体,推测为古河道,并与钻探结果相吻合,其埋深约56~96 m,弱风化基岩面埋深13.3~100 m,强风化及岩溶综合层厚一般约为5~20 m。基于古滑坡的地球物理勘探数据和解译结果,统计分析了川西岷江河谷地区大型—巨型古滑坡空间岩土体的地球物理物性参数,对指导该区滑坡调查分析具有重要的指导意义。     

琼东南盆地地壳伸展深度依赖性及其动力学意义

地壳或岩石圈尺度内伸展因子随深度变化特征对于理解岩石圈演化有重要的指示意义.我们利用南海北部大陆边缘琼东南盆地区深反射地震剖面的地壳分层模型,计算了沿剖面上地壳与全地壳的伸展因子.结果表明:琼东南盆地区具有明显的地壳尺度内伸展的深度相关性（上地壳尺度伸展因子变化范围为1.0~2.0,全地壳尺度的伸展因子变化范围为1.2~2.5）;琼东南盆地各构造单元内的上地壳与全地壳伸展具有明显的非均一性(长昌凹陷上地壳尺度伸展最大,乐东—陵水凹陷其次,松南—宝岛凹陷最小;长昌凹陷和松南—宝岛凹陷的地壳尺度伸展因子较乐东—陵水凹陷大) 与各向异性(南东—北西剖面较之北东—南西向剖面地壳伸展因子大).这些结果预示着琼东南盆地区地壳伸展优势方向为北西向,盆地区东西部的伸展过程或伸展机制可能差异较大拟或存在太平洋岩石圈俯冲角空间差异或地幔岩浆产出时空差异.结合研究区相关研究成果,推断地壳伸展因子的深度相关性可能是共轭大陆边缘低角度拆离控制的简单剪切系统内伴随地幔挤出的动力学现象.     

高压下华北北缘二辉麻粒岩电导率的研究

借助于YJ-3000t紧装式六面顶固体高压设备,在1.0~2.0 GPa、523~1173 K条件下,利用Agilent 34401A数字电表和Solartron IS-1260阻抗-增益/相位分析仪,同时使用三种方法:交流阻抗谱法(频率范围0.05~10⁶ Hz)、单频交流法(0.1 Hz)和直流法测量了华北北缘二辉麻粒岩的电导率.结果表明:在实验的温度和压力范围内,二辉麻粒岩电导率的变化在2.66×10^-5~0.056 S·m^-1之间,电导率对压力没有很强的依赖性;随着温度的升高,电导率增大,遵循Arrenhius关系式,其指前因子为8.95~17.9 S·m^-1,活化能为0.569~0.605 eV.对比三种方法获得的电导率数据,发现阻抗谱法测量结果大于单频法测量结果,直流法测得的结果最低,但是,三种方法获得的电导率差值除两个低温点外,绝大多数都很小(Δlgσ<0.20 lg(S/m)).结合现今华北克拉通地热学参数及地壳分层结构,依据实验获得的电导率温度关系建立了电导率-深度剖面.并将其与大地电磁测深获得的地壳电性结构进行了对比,结果表明二辉麻粒岩的电导率与华北北缘的中地壳底部和下地壳底部电导率值的区域相交,再结合高温高压下二辉麻粒岩的弹性波速度剖面与地震折射剖面的对比,认为二辉麻粒岩有可能是组成华北北缘下地壳的岩石之一.     

2008年汶川MS8.0地震对周边断层地震活动的影响

为分析2008年5月12日四川汶川M_S8.0级地震对周边断层地震活动的影响,本文首先基于Burgers体黏滞松弛模型计算汶川M_S8.0级地震引起的库仑应力动态演化,分析认为2008年汶川M_S8.0级地震在周边断层上引起的库仑应力显著增加的主要有四个断层段,分别为鲜水河断裂道孚-康定段、东昆仑断裂东段玛曲段、青川断裂和龙门山断裂南段.而且震后4年内黏滞松弛引起的库仑应力变化量可能与同震变化相当,相当于再发生一次汶川地震所造成的影响,因此震后效应在分析强震影响时不应忽略.本文基于强震引起的库仑应力变化动态演化,结合背景地震发生率、由Dieterich(1994)模型给出地震发生概率,结合相关构造地质、历史地震、余震活动等方面资料的综合分析认为,上述4个断裂段地震危险性由高到低依次为鲜水河断裂道孚-康定段、龙门山断裂南段、东昆仑断裂东段玛曲段和青川断裂.     

北黄海盆地烃渗漏蚀变带“磁亮点”的识别研究

北黄海盆地是我国近海海域尚未取得油气勘探突破的盆地之一.在海洋环境中应用海底油气藏的烃渗漏现象寻找油气有利区具有良好应用前景,为了给该区的含油气远景评价及下一步油气勘探缩小靶区提供地球物理依据,本文利用磁法这一经济、有效的油气渗漏异常地球物理判别手段,开展了识别海底烃渗漏引发磁异常的方法研究.给出一种根据“有导师”的模式识别技术,在充分利用磁异常多种数值特征及纹理特征的基础上,提取烃渗漏蚀变带磁异常的方法.通过已知约束信息（如见油井位等）的点、线、面三种基元及其邻近数据网格点组成基类,将其提取的模式或特征向量作为待识别异常匹配或学习的模板,利用加权欧氏距离函数计算待识别异常特征向量与模板向量之间的相似性,进行模式匹配,从而识别出与模板相似程度较高的异常.应用此方法圈定了北黄海盆地的烃渗漏“磁亮点”分布,从“磁亮点”异常区与中生代地层的分布以及地球化学异常（低层大气烃类检测和海底微生物异常）的对应情况来看,表明该识别方法是识别烃渗漏弱磁异常的一种有效手段.对研究区构造特征、磁异常及地球化学异常特征的综合分析表明,位于北黄海研究区东部和北部的“磁亮点”异常区可能是北黄海盆地较好的含油气远景区.     

Planners to the rescue: Spatial planning facilitating the development of offshore wind energy

The development of offshore wind energy has started to take place surprisingly quickly, especially in North European waters. This has taken the wind energy industry out of the territory of planning systems that usually govern the siting of wind farms on land, and into the world of departmental, sectoral regulation of marine activities. Although this has favoured the expansion of offshore wind energy in some respects, evidence suggests that the practice and principles of spatial planning can make an important contribution to the proper consideration of proposals for offshore wind arrays. This is especially so when a strategic planning process is put in place for marine areas, in which offshore wind is treated as part of the overall configuration of marine interests, so that adjustments can be made in the interests of wind energy. The current process of marine planning in the Netherlands is described as an illustration of this.     

Dynamic response of an offshore pile to pseudo-Stoneley waves along the interface between a poroelastic seabed and seawater

A coupled model is developed to investigate the dynamic interaction between an offshore pile, a porous seabed and seawater when subjected to the pseudo-Stoneley wave along the seabed and the seawater interface. The pile and the seabed are treated as the porous medium governed by Biot's theory, while the seawater is considered as an acoustic medium and is described by the conventional Helmholtz equation. The free field solution of the incident pseudo-Stoneley wave is obtained using Biot's theory and the potential method. Based on the boundary element method (BEM) for the porous medium and the acoustic medium, three BEM formulations are constructed for the pile, the seabed and the seawater, respectively, which are combined together using the continuity conditions between the pile, the seabed and the seawater to formulate the coupled model for the system. As shown in numerical examples, when the system is subjected to the pseudo-Stoneley wave, the maximum pore pressure of the seabed usually occurs at the region near the interfaces between the seabed and the seawater.