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991.
青岛榴辉岩及胶南群片麻岩的锆石U-Pb 年龄——胶南群中晋宁期岩浆事件的证据 总被引:2,自引:1,他引:2
研究表明,苏鲁地体是扬子与华北陆-陆碰撞造山带的一部分(东段)。其主要变质岩系——胶南群,是扬子陆块北缘俯冲陆壳的基底。在已有的文献中,人们均将胶南群划为早、中元古代地体。组成胶南群的主要岩石是长英质片麻岩,在其中间包含有少量斜长角闪岩、大理岩、超镁铁岩和榴辉岩。大量的Sm-Nd 及 40Ar/39Ar 同位素定年已证明了,胶南群在三叠纪时,经历了与华北和扬子陆块碰撞有关的高压或超高压变质作用,原岩的时代缺乏可靠的年龄测定,被认为是早、中元古代岩石。然而最近我们对青岛附近仰口的退变质榴辉岩及胶南群片麻岩的 相似文献
992.
作者详细推导了N个薄层介质组合时所引起的视各向异性介质的弹性参数,扩展了J.E.white先生在《Underground Sound》一书中关于双层介质组合的视各向异性介质的弹性参数应用范围,并计算了2个薄层各向同性的弹性介质组合时视各向异性介质中地震波速度随波动传播方向而变化的关系曲线,说明了薄层组合确实可以引起介质的视各向异性。 相似文献
993.
张喜发 《吉林大学学报(地球科学版)》1990,(4)
介绍孔隙水压力圆锥静力触探这门新技术,着重评述近年来在探头优化设计方面的进展,以及在划分地层和鉴别土类、估计土的超固结比和固结系数方面应用的最新研究成果。 相似文献
994.
本文利用EXAFS方法对镁铝榴石、几种锰矿和不同铁含量的闪锌矿中有关阳离子的近邻结构进行了研究,得到了有关阳离子在相应矿物中的近邻结构参数.对闪锌矿的研究,得到了杂质Fe绝大部分以六配位的形式存在的结果,这与传统的观点不同;提出了闪锌矿不仅可作为地质温度计,还可能作为地质温度、压力变化记录仪的设想。 相似文献
995.
新疆寒武纪三叶虫动物群可分为三个生物地理区:1.天山型动物群——博罗科努山区;2.华北型动物群——柯坪区;3.过渡型(库鲁克塔格型)动物群——库鲁克塔格区.库鲁克塔格寒武纪三叶虫动物群序列自下而上可分出13个化石带:下寒武统西大山组2个带;中寒武统莫合尔山组4个带;上寒武统突尔沙克塔格组7个带. 相似文献
996.
997.
微生物地球化学探矿—蜡样芽孢杆菌法寻找金,铀矿的试验研究 总被引:4,自引:0,他引:4
壤中蜡样芽孢杆菌找矿法是微生物地球化学探矿方法之一。本文叙述了蜡样芽孢杆菌法的找矿原理、野外工作方法、室内测量技术、野外初步试验的地质效果以及测量中应注意的若干问题。在已知隐伏金矿床(点)和铀矿床(点)上测得了明显的蜡样芽孢杆菌计数异常,并在460铀(钼)矿床外围的铀矿化远景地段进行了试验,地质效果较为理想。 相似文献
998.
A 352-year record of summer temperature reconstruction in the western Tianshan Mountains,China, as deduced from tree-ring density 总被引:2,自引:0,他引:2
Shulong Yu Yujiang YuanWenshou Wei Feng ChenTongwen Zhang Huaming ShangRuibo Zhang Li Qing 《Quaternary Research》2013
Three robust tree-ring density chronologies were developed for the western Tianshan Mountains of northwestern China. The chronologies were significantly correlated and form a regional chronology (GLD). The GLD had significant and positive correlations with temperature of warm seasons. Based on this relationship, the mean minimum temperatures of May to August were reconstructed using the GLD chronology for the period AD 1657 to 2008. The temperature reconstruction exhibited temperature patterns on interannual to centennial timescales, and showed that the end of the 20th century is the warmest period in the past 352 years. The reconstructed temperature variation has a teleconnection with large-scale atmospheric–oceanic variability and captures long- and broad-scale regional climatic variations. 相似文献
999.
Stable Isotope Composition of Rainfall,Surface Water and Groundwater along the Yellow River 下载免费PDF全文
The intention of this work is to consider the stable isotopic compositions of oxygen and deuterium in rainfall, surface water and groundwater along the Yellow River in the North China Plain (NCP). This demonstrated that the δ18O values in groundwater varied from –10.17 to –6.85‰, with mean value of –8.76‰, and that the δD ranged from –68.7 to –58.0‰, with mean value of –63.4‰, respectively. The δ18O values in surface water varied from –8.36 to 1.32‰, with mean value of –6.8‰, and δD ranged from –64.4 to –35.1‰, with mean value of –57.6‰, respectively. Further, The range of Cl- values of groundwater varied from 5.9 to 340.5 mg/L and that values ranged from 30.1 to 81.9 mg/L in surface water samples and Na+ value changed from 27.4 to 321 mg/L in groundwater, while that in surface water varied from 24.8 to 50.5 mg/L. Most of the points fall below the GMWL?, but are close to the LMWL.? Therefore the results indicated that the groundwaters along the Yellow River were influenced by rainfall in heavy events and surface water. 相似文献
1000.
Based on the results of previous studies and under the direction of the theory of “ore deposit genesis”, the authors made
use of high temperature and high pressure experimental facilities and conditions at the Tectono-geochemistry Research Room
under the State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, and put
the focus on the multi-source of tectonically controlling ore-forming materials, the characteristics of multi-stage and multi-episode
hydrothermal activities and mineralization and the characteristics of multi-genesis and multi-ore deposition so as to shed
light on the metallogenic mechanisms of super-large Cu and Au deposits. In addition simulating experiments were made on multi-stage
and multi-episode tectonic activities and rock and ore deformation, multi-stage and multi-episode tectonic activities and
mobilization and migration of ore-forming materials, and multi-stage and multi-episode tectonic activities and superimposition
and enrichment of ore-forming materials. The experimental results showed that under the action of multi-stage and multi-episode
tectonic stress the deformation and fragmentation of not only rocks and ores have been intensified, and but also the ore-forming
materials originally disbursed in the rocks and ores have been mobilized and migrated and superimposed and enriched. The experimental
results also provided the scientific experimental data and grounds for deep-going research on the rules of metallogenesis
and geneses of super-large ore deposits in the Dexing region, Jiangxi Province. 相似文献