黄骅埕古1井水位异常研究

黄骅埕古1井自2007年进行模拟静水位观测以来,曾出现多次水位异常变化,本项目通过对埕古1井水位资料与该井所处的地质构造和环渤海地区地震活动综合分析,认为该井的水位异常变化与环渤海地区地震活动存在一定的联系,埕古1井所处的部位是该地区的一个应力敏感点。     

山东西南部南四湖水位变化特征及其与气候要素的相关分析

气候变化对水资源的影响是水文领域的一个重要的研究方向, 研究水位变化与气候要素的相关分析, 对预测湖面水位意义重大. 利用1981-2013年山东西南部南四湖水位和沿湖5个国家级气象观测站逐月平均气温、 相对湿度、 风速、 降水和蒸发量等资料, 分析了近33 a来南四湖水位变化特征及气象影响因子. 结果表明: 近33 a南四湖水位升高趋势显著, 平均每10 a升高0.46 m; 水位变化整体分两个阶段, 1989年以前为下降态势, 1989年以后为上升态势, 1994年是水位升高的突变时间点; 平均最高水位出现在3月为33.04 m, 最低出现在12月为32.03 m. 各气象要素对南四湖水位的影响呈明显的季节性, 降水量是影响年水位变化的重要气象因子, 年降水量每增加100 mm, 水位升高0.21 m, 夏季降水量对水位的影响更为显著; 蒸发量在夏、 秋季与水位呈极显著负相关; 水位在夏季与风速、 在冬季与相对湿度均呈显著负相关.     

北京石花洞结构特征及发育演化过程研究

北京石花洞是中国北方已探明洞穴中次生碳酸盐沉积规模最大、种类最丰富的洞穴;石花洞的景观美学价值和科学价值,在我国北方岩溶洞穴中占有重要地位。2013年7月,为了获取石花洞发育规模、空间结构等基本数据,采用国际通用洞穴测量方法,运用激光测距仪、罗盘和倾角仪,辅以Onstation洞穴绘图软件和ArcMap10软件对石花洞洞穴开展了全面的调查和测绘。结果显示:(1) 石花洞洞穴系统整体呈北西西-南东东向展布,长度为5 639 m,洞底投影面积为37 096 m2,洞底高差为172 m,洞内最高点海拔约为265 m,最低点海拔约为93 m。洞穴系统的发育演化主要受地层产状与北东向和北西向两组断层控制;(2) 石花洞洞穴系统分为五层,自上而下,各层洞道平均海拔依次为249 m, 211 m, 154 m, 111 m和95 m;(3) 最底第五层季节性地下河洞道长1 638 m,自西北向东南方向贯穿整个洞穴系统,依干湿季水文条件的差别,地下水以季节性涨落为主要特征,有多段有水通道;地下河道下游末端为叉状河道,崩塌明显,洞壁上无明显流纹发育;(4) 综合石花洞地下河走向和流向、洞穴发育控制因素和区域地层产状特征、石花洞与周边洞穴的空间位置关系,推测孔水洞是石花洞洪水期的排泄口。      

江苏及邻近地区地震视应力特征研究

采用江苏省数字地震台网记录的地震波形资料,利用震源位移谱低频水平与拐角频率计算了2000~2010年江苏及邻近地区561个ML≥1.5中小地震视应力值。结果显示,江苏及邻近地区的地震视应力平均值为0.91 MPa,与中国大陆的平均水平相当。视应力与震级无明显的线性关系,在震级相对较大时表现出一定的高震级对应高视应力的特点。视应力高值地区主要集中在江苏中部至南黄海海域,次高值集中分布在郯庐断裂带中南段的苏鲁交界地区、安徽段固镇至定远附近地区和肥东、巢湖一带,反映了以上地区较高的地震活动水平及地壳应力状态。不同区域ML2震级档视应力的差异性基本反映了区域地质环境、构造活动等特征的差异。     

新一代高速对向观测数字水准尺仪的发明与实践

水准测量一直是获得地面点精密高差的重要手段,其测量速度慢、效率低也一直是困扰全球测量界的一大难题。为了提高水准测量的速度和效率,本文提出了新一代高速对向观测数字水准尺仪的概念、结构、原理与方法。具体采用水准仪与标尺合二为一的一体化结构设计,将传统水准测量的3点互动配置改变为2点互动配置来提高测站仪器安置速度和地形适应能力;采用对偶测量原理将传统水准测量的单向单系统测量改变为对（双）向双系统测量来提高水准测量的精度及可靠性;采用正交二脚架及L型水准器来提高水准标尺及水准仪的安平速度。理论分析及初步实践表明：新一代高速对向观测数字水准尺仪与传统水准仪相比,水准测量效率可提高1倍以上,是目前世界上最快速、最智能、最精密的电子水准测量系统。高速对向观测数字水准尺仪的发明,将对全球大地及工程测量界产生重大及颠覆性的影响,将开启人类社会普及电子水准仪的新时代。     

海岛岸线遥感立体测图精细测量方法

提出了一种海岛岸线遥感测图精细测量新方法,该方法直接基于理论定义的海岸线,利用航空影像瞬时水涯线数据在立体测图环境中提取瞬时水位高程;利用海岛周边精密海潮模型和瞬时水位高程推算海岛岸线高程;最后依据海岛岸线高程,采用立体测图方法测制海岛岸线的平面位置。该方法确保了海岛岸线成果的唯一性和连续性,适合大比例尺的大陆海岸线和海岛岸线测量。测试结果显示,在较高精度海潮模型和海面地形支持下,海岛岸线高程精度优于0.2 m,可满足1：2000测图要求。     

Cenozoic metallogeny of Greece and potential for precious,critical and rare metals exploration

The Cenozoic metallogeny in Greece includes numerous major and minor hydrothermal mineral deposits, associated with the closure of the Western Tethyan Ocean and the collision with the Eurasian continental plate in the Aegean Sea, which started in the Cretaceous and is still ongoing. Mineral deposits formed in four main periods: Oligocene (33–25 Ma), early Miocene (22–19 Ma), middle to late Miocene (14–7 Ma), and Pliocene-Pleistocene (3–1.5 Ma). These metallogenic periods occurred in response to slab-rollback and migration of post-collisional calc-alkaline to shoshonitic magmatism in a back-arc extensional regime from the Rhodopes through the Cyclades, and to arc-related magmatism along the active south Aegean volcanic arc. Invasion of asthenospheric melts into the lower crust occurred due to slab retreat, and were responsible for partial melting of metasomatized lithosphere and lower crustal cumulates. These geodynamic events took place during the collapse of the Hellenic orogen along large detachment faults, which exhumed extensive metamorphic core complexes in mainly two regions, the Rhodopes and the Cyclades. The detachment faults and supra-detachment basins controlled magma emplacement, fluid circulation, and mineralization.The most significant mineralization styles comprise porphyry, epithermal, carbonate-replacement, reduced intrusion-related gold, intrusion-related Mo-W and polymetallic veins. Porphyry and epithermal deposits are commonly associated with extensive hydrothermal alteration halos, whereas in other cases alteration is of restricted development and mainly structurally controlled. Porphyry deposits include Cu-Au-, Cu-Mo-Au-Re, Mo-Re, and Mo-W variants. Epithermal deposits include mostly high- and intermediate-sulfidation (HS and IS) types hosted in volcanic rocks, although sedimentary and metamorphic rock hosted mineralized veins, breccias, and disseminations are also present. The main metal associations are Cu-Au-Ag-Te and Pb-Zn-Au-Ag-Te in HS and IS epithermal deposits, respectively. Major carbonate-replacement deposits in the Kassandra and Lavrion mining districts are rich in Au and Ag, and together with reduced intrusion-related gold systems played a critical role in ancient economies. Finally hundreds of polymetallic veins hosted by metamorphic rocks in the Rhodopes and Cyclades significantly add to the metal endowment of Greece.     

Modern diatom assemblages from Chilean tidal marshes and their application for quantifying deformation during past great earthquakes

Tidal marsh sediments from south‐central Chile provide evidence for multiple great earthquakes. Diatom transfer functions, statistical models of the relationship between species preserved in the sediment and elevation, provide quantitative estimates of coseismic vertical land‐level change associated with individual earthquakes. However, in south‐central Chile, our ability to quantify land‐level change is currently limited by a lack of understanding of the environmental variables controlling the distribution of diatoms, an essential prerequisite for converting variations in fossil diatom assemblages into quantitative estimates of past elevation changes. We present a new modern diatom dataset for the region and explore the implications of the scale of the dataset used in transfer function models on the reconstructions of land‐level change. Modern training sets containing samples from a regional scale are superior to sub‐regional and local‐scale training sets, providing closer estimates for known deformation during the great 1960 Chilean earthquake, a higher proportion of good modern analogues and uncertainty terms up to 42% smaller than previously published reconstructions. Copyright © 2017 The Authors. Journal of Quaternary Science Published by John Wiley & Sons Ltd.

     

广州金沙洲岩溶地面塌陷灾害预警预报研究

受武广客运专线金沙洲隧道施工抽排大量地下水的影响, 2007—2012年广州金沙洲发生了大规模岩溶地面塌陷、地面沉降地质灾害,造成了重大经济损失。为防治地质灾害,采用综合地质调查、地下水位监测、地面沉降监测、物探、钻探和试验等手段勘查和研究,建立了完善的地下水位和地面沉降监测网络。在此基础上,根据地质环境条件、岩溶发育程度和地质灾害分布特征进行岩溶塌陷易发性分区,选择地下水位变化量和地面沉降量这两个与岩溶塌陷最直接、最敏感和最重要的参数,从预警预报参数选择、时间尺度选取、判据分析计算、预警预报方法、模型系统的建立等方面进行研究,选取临界日综合地下水位变化量和临界日综合地面沉降量作为预警预报判据,结合三维地质结构模型建立岩溶塌陷预警预报模型系统。成功地预警预报了两起岩溶地面塌陷,取得较好的预报效果,说明该岩溶地面塌陷预警预报模型系统实用、有效,为金沙洲防灾减灾提供地质科学依据,为当地的社会稳定和经济可持续发展提供技术支撑。