峨眉山玄武岩研究中的一些问题的讨论   总被引：39，自引：3，他引：39  

张招崇  王福生  范蔚茗  邓海琳  徐义刚  许继峰  王岳军 《岩石矿物学杂志》2001,20(3):239-246

峨眉山玄武岩是当前研究的特点，本文从以下方面论述了峨眉山玄武岩研究中存在的一些问题：时空分布；岩石组合；高Ti和低Ti玄武岩；与其它典型大陆溢流玄武岩的异同点；与地幔柱的关系和地幔柱的起因。对这些问题提出了一些新的认识和解释，或者提出了解决这些问题的途径。这些问题的解决，对研究娥眉山玄武岩本身以及地幔柱－岩石圈的相互作用及其成矿效应均具有重要意义。  相似文献   

合成磷灰石的去氟机理研究          下载免费PDF全文

黄志良  刘羽  王大伟  张术根  陈露军 《岩石矿物学杂志》2001,20(4):568-572

用固相反应法和sol-gel法合成了不同类型的磷灰石（AP），并采用TEM、XRD、IR、BET比表面积法及静、动态吸附等方法研究了不同AP的比表面积、结晶度、晶胞参数、结晶尺寸、晶格缺陷度、Ca/P摩尔比和煅烧温度等与吸氟能力的关系，结果表明：结晶度高、晶粒大的AP有较小的吸氟量，属表面单分子层化学络合吸附机理；酸活化的AP有较大的吸氟量，属溶解-沉淀与沉淀物表面纳米尺寸效应吸附的复合去氟机理；具纳米尺寸的HAP在常温、常压、无二次污染、小于11mg/L的低含氟浓度废水中且不酸化情况下有较大吸氟量，属纳米尺寸效应吸附机理。  相似文献   

东马珠穆沁旗中铁陨石表面的角砾状橄榄石的特征     

陶克捷  杨主明等 《岩石学报》2001,17(2):321-324

东乌珠穆沁旗中铁陨石中有二种橄榄石。一种是陨石中基质橄榄石，另一种是镶嵌在陨石表面的角砾状橄榄石。电子探针成分分析结果表明，两种橄榄石中的FeO和MnO比值，包体矿物种类，包体铁纹石和镍纹石中Fe,Ni的含量等，均有较大区别。陨石中基质橄榄石矿物是本陨石中原物质，而角砾状橄榄石是宇宙中物质。他们是两块自由翱于宇宙中的物质碰撞混合而形成的东乌珠穆旗陨石中这种现象。  相似文献   

缅甸含硬玉的蛇纹石化橄榄岩及其围岩的岩石学研究   总被引：13，自引：6，他引：13  

施光海  崔文元等 《岩石学报》2001,17(3):483-490

以缅甸帕敢地区含硬玉岩的蛇纹石化橄榄岩及其围岩－未细分的变质岩为研究对象，较详细地研究了各类岩石的岩相学，岩石化学及主要矿物的组成，认为该区超基性岩为含铬铁矿的蛇纹石化纯橄岩，它的围岩由含多硅白母蓝闪石片岩，石榴斜长角闪岩，大理岩及透辉石大理岩，石英岩等构成。通过其中典型的变质反应分析与计算，认为围岩的变质程度分别为蓝闪石片岩相和的高角闪岩相，其中蓝闪石片岩相的压力大于0．8－1．0GPa，斜长角闪岩相的温度为582度，通过对比分析世界上不同产地硬玉岩的特征，认为硬玉岩，尤其是优质者，产出环境如下：（1）容矿岩体属超基性岩，以含铬铁矿的纯橄岩为最佳；（2）围岩中存在低温高压变质岩，即蓝闪石片岩－榴辉岩类；（3）位于与俯冲带有关大地构造单元内。  相似文献   

无网格伽辽金法应用的参数选择及内部边界处理   总被引：8，自引：0，他引：8  

张延军  张晓炜 《工程地质学报》2001,9(3):321-325

无网格辽金法作为-种新的岩土工程数值计算方法, 该法其只需节点信息的无单元特性, 使其具有计算优势。本文结合固结EFGM刚度矩阵公式, 对不同的计算参数进行计算分析, 找出其影响规律。并采用跳跃函数处理内部边界条件, 计算结果表明, EFGM处理内部场函数不连续是准确的。  相似文献   

Quaternary vertical offset and average slip rate of the Nojima Fault on Awaji Island, Japan   总被引：5，自引：0，他引：5  

Akihiro Murata  Keiji Takemura  Takao Miyata  Aiming Lin 《Island Arc》2001,10(3-4):360-367

Abstract Drilling was carried out to penetrate the Nojima Fault where the surface rupture occurred associated with the 1995 Hyogo-ken Nanbu earthquake. Two 500 m boreholes were successfully drilled through the fault zone at a depth of 389.4 m. The drilling data show that the relative uplift of the south-east side of the Nojima Fault (south-west segment) was approximately 230 m. The Nojima branch fault, which branches from the Nojima Fault, is inferred to extend to the Asano Fault. From the structural contour map of basal unconformity of the Kobe Group, the vertical component of displacement of the Nojima branch–Asano Fault is estimated to be 260–310 m. Because the vertical component of displacement on the Nojima Fault of the north-east segment is a total of those of the Nojima Fault of the south-west segment and of the Nojima branch–Asano Fault, it is estimated to total to 490–540 m. From this, the average vertical component of the slip rate on the Nojima Fault is estimated to be 0.4–0.45 m/10³ years for the past 1.2 million years.  相似文献   

Evaluation of density in layer compaction using SASW method   总被引：1，自引：0，他引：1  

Dong-Soo Kim  Min-Kyun Shin  Hyung-Choon Park   《Soil Dynamics and Earthquake Engineering》2001,21(1)

SASW test, which is non-intrusive and rapid in the field application, was used to evaluate the layer density in the roller compaction without performing the complicated inversion process. The concept of normalized shear wave velocity was introduced to minimize the effect of confinement in the density evaluation. SASW test was performed to determine the shear wave velocity of the layer, and the free–free resonant column (FF–RC) test was adopted to determine the correlation between the normalized shear wave velocity and density of the site, which is almost unique independent of confinement. Testing and data reduction procedures of both tests were briefly discussed and an evaluation procedure of the field density was proposed by effectively combining in-situ shear wave velocity determined by the SASW test with the correlation between the normalized shear wave velocity and the density determined by the FF–RC test. Finally, the feasibility of the proposed method was verified by performing a field case study at Hoengsung road construction site. Field densities determined by the proposed method matched well with those determined by sand cone tests, showing the potential of applying the proposed method in the field density evaluation.  相似文献   

The Green''''s function of the harmonic horizontal force applied at the interior of the saturated half-space soil     

陆建飞  王建华  沈为平 《地震学报(英文版)》2001,(2)

IntroductionThe wave propagation problems in saturated soil are very important for the civil engineering, geophysics and seismology. Biot (1956,1962) established the theory of wave propagation in saturated soil firstly, and hereafter many researchers have used Biot theory to study wave propagation problems in saturated soil. By using integral transform and potential function method, Philippacopoulos (1988) studied the Lamb(s problem of a vertical point force applied to the surface of saturate…  相似文献   

Use of a shared tuned mass damper (STMD) to reduce vibration and pounding in adjacent structures     

Makola M. Abdullah  Jameel H. Hanif  Andy Richardson  John Sobanjo 《地震工程与结构动力学》2001,30(8):1185-1201

The dynamic response of tall civil structures due to earthquakes is very important to civil engineers. Structures exposed to earthquakes experience vibrations that are detrimental to their structural components. Structural pounding is an additional problem that occurs when buildings experience earthquake excitation. This phenomena occurs when adjacent structures collide from their out‐of‐phase vibrations. Many energy dissipation devices are presently being used to reduce the system response. Tuned mass dampers (TMD) are commonly used to improve the response of structures. The stiffness and damping properties of the TMD are designed to be a function of the natural frequency of the building to which it is connected. This research involves attaching adjacent structures with a shared tuned mass damper (STMD) to reduce both the structures vibration and probability of pounding. Because the STMD is connected to both buildings, the problem of tuning the STMD stiffness and damping parameters becomes an issue. A design procedure utilizing a performance function is used to obtain the STMD parameters to result in the best overall system response. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

Petrochemical Investigation of the Antique Ophiolite (Philippines): Implications on Volcanogenic Massive Sulfide and Podiform Chromitite Deposits   总被引：5，自引：0，他引：5  

Rodolfo A. TAMAYO Jr    Graciano P. YUMUL Jr    René C. MAURY  Mireille POLVÉ  Joseph COTTEN  Marcel BOHN 《Resource Geology》2001,51(2):145-164

Abstract: The Antique ophiolite, located in Panay island (west‐central Philippines), corresponds to several tectonic slices within the suture zone between the Philippine Mobile Belt (PMB) and the North Palawan Block (NPB). It includes dismembered fragments of a basaltic sequence, dominantly pillow‐lavas with minor sheet flows, rare exposures of sheeted dikes, isotropic gabbros, subordinate layered mafic and ultramafic rock sequences and serpentinites. Most of the ophiolite units commonly occur as clasts and blocks within the serpentinites, which intrude the whole ophiolitic body, as well as, the basal conglomerate of the overlying Middle Miocene sedimentary formation. The volcanic rock sequence is characterized by chemical compositions ranging from transitional (T)‐MORB, normal (N)‐MORB and to chemistry intermediate between those of MORB and island arc basalt (IAB). The residual upper mantle sequence is harzburgitic and generally more depleted than the upper mantle underlying modern mid‐oceanic ridges. Calculations using whole‐rock and mineral compositions show that they can represent the residue of a fertile mantle source, which have undergone degrees of partial melting ranging from 9‐22.5 %. Some of the mantle samples display chondrite‐nor‐malized REE and extended multi‐element patterns suggesting enrichments in LREE, Rb, Sr and Zr, which are comparable to those found in fore‐arc peridotites from the Izu‐Bonin‐Mariana (IBM) arc system. The Antique ultramafic rocks also record relatively oxidizing mantle conditions (Δlog f_O2 (FMQ)=0.9‐3.5). As a whole, the ophiolite probably represents an agglomeration of oceanic ridge and fore‐arc crust fragments, which were juxtaposed during the Miocene collision of the PMB and the NPB. The intrusion of the serpentinites might be either coeval or subsequent to the accretion of the oceanic crust onto the fore‐arc. Volcanogenic massive sulfide (VMS) deposits occur either in or near the contact between the pillow basalts and the overlying sediments or interbedded with the sediments. The morphology of the deposits, type of metals, ore texture and the nature of the host rocks suggest that the formation of the VMS bodies was similar to the accumulation of metals around and in the subsurface of hydrothermal vents observed in modern mid‐oceanic ridge and back‐arc basin rift settings. The podiform chromitites occur as pods and subordinate layers within totally serpentinized dunite in the residual upper mantle sequence. No large coherent chromitite deposit was found since the host dunitic rocks often occur as blocks within the serpentinites. It is difficult to evaluate the original geodynamic setting of the mineralized bodies since the chemistry of the host rocks were considerably modified by alteration during their tectonic emplacement. A preliminary conclusion for Antique is that the VMS is apparently associated with a primitive tholeiitic intermediate MORB‐IAB volcanic suite, the chemistry of which is close to the calculated composition of the liquid that coexisted with the podiform chromitites.  相似文献