遥感技术在断裂研究中的应用——以张家口—蓬莱断裂带为例

张家口一蓬莱断裂带是一条北西西向活动断裂带。本文选取ETM+光学影像和SRTM高程影像作为主要数据源,结合研究区已有地质资料研究发现该带断裂构造的北西西向线性特征明显。从水系分布和错断地形等地貌标志判断,该断裂具有左阶组合样式和左行走滑活动特征。据遥感影像综合特征,可将该带分为张家口段、延庆-怀来段和北京一天津段,影像特征分段性显著,并与断裂带的分段性一致。研究结果表明,张家口-蓬莱断裂具有左行走滑的运动学特征,限制或错断北北东或北东向断裂,并且控制该区域的左阶雁列式第四纪盆地群和第四纪冲洪积物的分布。该断裂带各段对不同规模的水系分布和形态影响比较大,且北京-天津地区的华北平原段断裂对第四纪冲洪积扇和沿海地区的贝壳堤的形态和分布有一定的控制作用。地球物理深部数据和野外地质考察资料也证实了遥感解泽的结果,证明遥感技术在探查断裂构造空间展布和活动性鉴定中有着广泛的应用前景。     

基于AHP对边坡挡土墙稳定性评价方法研究

边坡挡土墙紧邻边坡,其稳定性不仅受自身结构及质量的制约,在很大程度上也受到附近地质环境的影响。珠海万山区分布大量该类型挡土墙,且发生过多处墙体垮塌事件,带来经济损失,影响严重。采用AHP法分析并评价边坡挡土墙的稳定性。     

High‐Precision Measurement of Molybdenum Isotopic Compositions of Selected Geochemical Reference Materials

Here we describe high‐precision molybdenum isotopic composition measurements of geological reference materials, performed using multi‐collector inductively coupled plasma‐mass spectrometry (MC‐ICP‐MS). Purification of Mo for isotopic measurements was achieved by ion exchange chromatography using Bio‐Rad AG^® 1‐X8 anion exchange resin. Instrumental mass bias was corrected using ¹⁰⁰Mo‐⁹⁷Mo double spiking techniques. The precision under intermediate measurement conditions (eighteen measurement sessions over 20 months) in terms of δ^98/95Mo was 0.10‰ (2s). The measurement output was approximately four times more efficient than previous techniques, with no compromise in precision. The Mo isotopic compositions of seven geochemical reference materials, seawater (IAPSO), manganese nodules (NOD‐P‐1 and NOD‐A‐1), copper‐molybdenum ore (HV‐2), basalt (BCR‐2) and shale (SGR‐1b and SCo‐1), were measured. δ^98/95Mo values were obtained for IAPSO (2.25 ± 0.09‰), NOD‐P‐1 (?0.66 ± 0.05‰), NOD‐A‐1 (?0.48 ± 0.05‰), HV‐2 (?0.23 ± 0.10‰), BCR‐2 (0.21 ± 0.07‰), SCo‐1 (?0.24 ± 0.06‰) and SGR‐1b (0.63 ± 0.02‰) by calculating δ^98/95Mo relative to NIST SRM 3134 (0.25‰, 2s). The molybdenum isotopic compositions of IAPSO, NOD‐A‐1 and NOD‐P‐1 obtained in this study are within error of the compositions reported previously. Molybdenum isotopic compositions for BCR‐2, SCo‐1 and SGR‐1b are reported for the first time.     

基于高空间分辨率卫星遥感影像的围填海存量资源监测与评估研究——以营口市南部海岸为例

为详细掌握围填海存量资源状态,提高海域空间资源监管精细化水平,本文提出围填海存量资源概念,并将围填海存量资源划分为围而未填区域、填而未建区域、低密度建设区域、低洼坑塘、低效盐田和低效养殖池塘等6种类型,以及工业区、城镇区等围填海存量资源的消耗类型。在此基础上,采用高空间分辨率卫星遥感影像,建立了面向对象的围填海存量资源遥感影像分类提取方法与技术流程,构建了围填海存量资源指数,并以营口市南部海岸区域为例进行了实证研究。结果表明:（1）面向对象的围填海存量资源遥感影像分类提取方法能够精细地提取围填海存量资源信息,准确率达到90%以上;（2）填而未建区域、低效盐田、低效养殖池塘占研究区围填海存量资源总面积的62.51%,研究区围填海存量资源指数为0.49,但内部差异明显,北部区域为0.66,中部区域为0.44,南部区域为0.37。     

川东南桑木场背斜寒武系脉体分形特征及其意义

通过对川东南桑木场背斜寒武系多期脉体野外详细构造特征、几何学特征的勘测,利用分形学研究方法对1200余条(古流体活动)脉体进行综合定量研究表明,寒武系节理脉体主要为限制脉体(层内脉体、层间脉体、断层相关层间脉体)、贯通脉体(隆张成因)两大类,它们具有不同的分形(分维值、变差系数等)特征,反映差异性古流体活动能力。层内脉体厚度分维值D=1.332～2.307,脉体间距呈负指数分布,变差系数Cv=0.7～1.0;层间脉体厚度分维值D=0.995～1.690,脉体间距呈对数正态分布为主,变差系数Cv=0.65～1.00;断层相关层间脉体厚度分维值D=1.048～1.254,脉体间距呈负指数和对数正态分布,变差系数Cv=0.5～0.9;隆张成因贯通脉体厚度分维值D=0.917(1),脉体间距呈幂率分布,变差系数Cv=1.5,流体(跨层)活动能力强。多期脉体具有渗流模型机制扩展生长特性,晚期隆升作用对桑木场背斜地区寒武系古流体活动以及区域保存条件具有至关重要的影响。     

江西修水下古生界岩层中的水力破裂现象及其意义

本文简要阐述了水力破裂的基本原理和工作方法。通过对江西修水下古生界岩层中的水力破裂现象描述和分类,分析其形成条件和构造环境。指出水力破裂作用在修水地区对多级滑脱构造的研究具有重要意义。     

孟加拉湾云团影响下云南强降水分析

2001年云南初夏洪涝与孟加拉湾(简称孟湾)云的活动密切相关，本文分析了云南强降水过程中几次孟加拉湾云团发展的大尺度动、热力背景和卫星云图的TBB特征。结果表明：孟加拉湾北上云贵高原的对流云必须得到足够的辐合和抬升动力，才能在高原维持和进一步发展；青藏高原横槽是孟加拉湾云团在云贵高原产生强降水的重要天气系统；孟加拉湾云团的发展与正压和斜压不稳定均有关系；冷空气对北上孟加拉湾云团的发展至关重要，它不但有利于水汽凝结量的增加，还有利于形成强降水天气发生的动力、热力环境；TBB分布更直观地反映了孟加拉湾云团的活动，≤-52℃的冷云覆盖区与云南强降水落区有较好的关系。     

Kanfenggou UHP Metamorphic Fragment in Eastern Qinling Orogen and Its Relationship to Dabie-Sulu UHP and HP Metamorphic Belts, Central China

In the Central Orogenic Belt, China, two UHP metamorphic belts are discriminated mainly based on a detailed structural analysis of the Kanfenggou UHP metamorphic fragment exposed in the eastern Qinling orogen, and together with previous regional structural, petrological and geochronological data at the scale of the orogenic domain. The first one corresponds to the South Altun-North QaidamNorth Qinling UHP metarnorphic belt. The other is the Dabie-Sulu UHP and HP metamorphic belts. The two UHP metamorphic belts are separated by a series of tectonic slices composed by the Qiniing rock group, Danfeng rock group and Liuling or Foziling rock group etc. respectively, and are different in age of the peak UHP metamorphism and geodynamic implications for continental deep subduction and collision. Regional field and petrological relationships suggest that the Kanfenggou UHP metamorphic fragment that contains a large volume of the coesite- and microdiamond-bearing eclogite lenses is compatible with the structures recognized in the South Altun and North Qaidam UHP metamorphic fragments exposed in the western part of China, thereby forming a large UHP metamorphic belt up to 1000 km long along the orogen strike. This UHP metamorphic belt represents an intercontinental deep subduction and collision belt between the Yangtze and Sino-Korean cratons, occurred during the Paleozoic. On the other hand, the well-constrained Dabie-Sulu UHP and HP metamorphic belts occurred mainly during Triassic time (250-220 Ma), and were produced by the intracontinental deep subduction and collision within the Yangtze craton. The Kanfenggou UHP metamorphic fragment does not appear to link with the DabieSulu UHP and HP metamorphic belts along the orogen. There is no reason to assume the two UHP metamorphic belts as a single giant deep subduction and collision zone in the Central Orogenic Belt situated between the Yangtze and Sino-Korean cratons. Therefore, any dynamic model for the orogen must ac-count for the development of UHP metarnorphic rocks belonging to the separate two tectonic belts of different age and tectono-metamorphic history.     

Sequence of Ductile Shear Zones in UHP Metamorphic Province within Dabie Massif, China

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