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1.
安徽铜陵铜官山矿区中生代侵入岩的形成过程——岩浆底侵、同化混染和分离结晶 总被引：30，自引：2，他引：28
对安徽铜陵铜官山矿区的小铜官山岩体进行了SHRIMP锆石U-Pb定年,并对天鹅抱蛋山岩体及其辉长岩和闪长岩包体进行了全岩主量元素和稀土元素以及锶 钕同位素分析,结合对区内老庙基山和小铜官山岩体及其辉长岩和闪长岩包体的岩石学和地球化学资料的综合整理,讨论了这些岩体及其包体的成因。小铜官山岩体的SHRIMP锆石U-Pb年龄为(139.5±2.9 ）Ma,表明它属于长江中下游晚侏罗世-早白垩世岩浆作用的产物。辉长岩和闪长岩包体具有低w(SiO2)(52.03%~54.61 %）、w(Al2O3)(12.87%~14.43 %)和全碱含量w(Na2O+K2O)(5.26%~6.30 %）, 但高w(MgO)(5.41%~11.66 %）的特征;寄主岩与此相反,具有高w(SiO2)(59.97%~64.44 %）、w(Al2O3)(16.43%~17.59 %）和全碱含量(6.67%~8.25 %）,但低w(MgO)(1.52%~2.50 %）的特征。辉长岩和闪长岩包体的稀土元素总量为165.70×10-6~190.40×10-6,寄主岩的稀土元素总量为166.12×10-6~185.95×10-6,二者十分相近,它们的稀土元素球粒陨石标准化配分模式也十分相似。但辉长岩和闪长岩包体的轻、重稀土比值为3.39~4.27,明显小于寄主岩的轻、重稀土比值(4.86~5.94）。辉长岩和闪长岩包体具明显的正铕异常,而寄主岩具有弱负铕异常。从辉长岩到寄主岩,ε Nd (t) 从-4.9~-9.9减小到-11.4~-11.9,(87Sr/86Sr)o 从0.706 4~0.707 3增加到0.707 2~0.708 4。上述资料表明,铜陵铜官山矿区晚侏罗世-早白垩世侵入岩及其辉长岩和闪长岩包体可能是由基性到中酸性岩浆通过幔源岩浆底侵、同化混染和分离结晶过程形成的,而基性到中酸性岩浆则是由底侵的玄武岩浆与不同量的中下地壳物质发生一系列复杂的相互作用形成的。 相似文献
2.
YANG RuidongDepartment of Earth Sciences Nanjing University Nanjing Jiangsu ZHAO Yuanlong Guizhou University of Industry Guiyang Guizhou 《《地质学报》英文版》1998,72(3):329-333
Recently a rich and well-preserved crinoid community including Traumatocrinus and Encrinus has been found in the Late Triassic Zhuganpo Formation in Guanling and Xingyi, Guizhou province, China. Among the fossils Traumatocrinus is the richest, and most of it occurs as clusters, with each cluster containing 3-42 crinoid branches. Study of the stem and calyx of Traumatocrinus shows that the number of stem-joints (columnals) is equal to the total stem length × K (5.85 per cmx stem-diameter). There are about 376 first- and second-order columnals on the whole stem. This number seems to coincide with the number of days in a year at that time. According to the present study of the palaeoecological environment of the crinoid community, it is considered that the reproduction and preservation of the crinoid community were controlled by the Late Triassic regression and the restricted bay of an interior sea behind the S-shaped shoal zone. 相似文献
3.
THE HIGH RESOLUTION SEISMIC TOMOGRAPHIC IMAGE IN QINGHAI—TIBET PLATEAU AND ITS DYNAMIC IMPLICATIONS 总被引：1，自引：1，他引：0
THE HIGH RESOLUTION SEISMIC TOMOGRAPHIC IMAGE IN QINGHAI—TIBET PLATEAU AND ITS DYNAMIC IMPLICATIONSeasthenospherehadbe 相似文献
4.
Abdullah I. Al-Mhaidib 《Geotechnical and Geological Engineering》2006,24(4):889-902
The behavior of pile groups in sand under different loading rates is investigated. A total of 60 tests were conducted in the
laboratory using model steel piles embedded in a medium dense sand. The model piles have an outside diameter of 25 mm and
embedment length of 500 mm. Five different configurations of pile groups (2 × 1, 3 × 1, 2 × 2, 2 × 3, 3 × 3) with center to
center spacing between the piles of 3d, 6d and 9d (d is the pile diameter) were tested. The piles were subjected to axial compressive loads under four different loading rates:
1.0, 0.5, 0.1 and 0.05 mm/min. Test results indicated that the axial compressive capacity of pile group increases with the
loading rate such that the pile capacity versus logarithm of loading rate data plot approximately along a straight line. The
slope of this line increases as the number of piles in a group increases and it decreases by increasing the spacing between
piles in a group. 相似文献
5.
作为高新产业重要原材料的关键金属,在地壳内平均含量低和分布不均匀,使得其优势矿床类型尚不清晰,尤其是多类型多金属的共存储库—斑岩-矽卡岩-浅成低温热液成矿系统内共(伴)生的关键金属值得深入关注。北衙多金属矿是金沙江-哀牢山成矿带内与喜山期富碱斑岩有关的斑岩型铜金钼-矽卡岩型铁金铜-浅成低温热液型铅锌银金复合成矿系统。在系统梳理前人有关主体金属矿物原位微量元素研究的基础上,本次研究初步查明共伴生的关键金属包括四种：(1) Re：赋存于斑岩型和矽卡岩型矿化的辉钼矿中,含量为2.51×10-6～62.64×10-6;(2) Co：以类质同象替代形式赋存于矽卡岩型矿化的磁铁矿中,含量为0.13×10-6～41.1×10-6;(3) Bi：以铋化物形式赋存于斑岩型和矽卡岩型矿化中,包括铋铅矿、Bi-Cu硫盐、Bi-Pb硫盐、Bi-Ag硫盐、Bi-Cu-Pb硫盐、Bi-Pb-Ag硫盐和含Bi硫族化合物,其中辉铋矿是主要含铋矿物;(4) Te：赋存于斑岩型、矽卡岩型和浅成低温热液型矿化的硫化物(碲含量：80×10... 相似文献
6.
The Biot linearized quasi-static theory of fluid-infiltrated porous materials is used to formulate the problem of the two-dimensional
plane strain deformation of a multi-layered poroelastic half-space by surface loads. The Fourier-Laplace transforms of the
stresses, displacements, pore pressure and fluid flux in each homogeneous layer of the multi-layered half-space are expressed
in terms of six arbitrary constants. Generalized Thomson-Haskell matrix method is used to obtain the deformation field. Simplified
explicit expressions for the elements of the 6 × 6 propagator matrix for the poroelastic medium are obtained. As an example
of the possible applications of the analytical formulation developed, formal solution is given for normal strip loading, normal
line loading and shear line loading. 相似文献
7.
The thermal expansion of gehlenite, Ca2Al[AlSiO7], (up to T=830 K), TbCaAl[Al2O7] (up to T=1100 K) and SmCaAl[Al2O7] (up to T=1024 K) has been determined. All compounds are of the melilite structure type with space group
Thermal expansion data were obtained from in situ X-ray powder diffraction experiments in-house and at HASYLAB at the Deutsches
Elektronen Synchrotron (DESY) in Hamburg (Germany). The thermal expansion coefficients for gehlenite were found to be: α1=7.2(4)×10−6×K−1+3.6(7)×10−9ΔT×K−2 and α3=15.0(1)×10−6×K−1. For TbCaAl[Al2O7] the respective values are: α1=7.0(2)×10−6×K−1+2.0(2)×10−9ΔT×K−2 and α3=8.5(2)×10−6×K−1+2.0(3)×10−9ΔT×K−2, and the thermal expansion coefficients for SmCaAl[Al2O7] are: α1=6.9(2)×10−6×K−1+1.7(2)×10−9ΔT×K−2 and α3=9.344(5)×10−6×K−1. The expansion mechanisms of the three compounds are explained in terms of structural trends obtained from Rietveld refinements
of the crystal structures of the compounds against the powder diffraction patterns. No structural phase transitions have been
observed. While gehlenite behaves like a ‘proper’ layer structure, the aluminates show increased framework structure behavior.
This is most probably explained by stronger coulombic interactions between the tetrahedral conformation and the layer-bridging
cations due to the coupled substitution (Ca2++Si4+)–(Ln
3++Al3+) in the melilite-type structure.
This article has been mistakenly published twice. The first and original version of it is available at . 相似文献
8.
再论花岗岩按照Sr-Yb的分类:标志 总被引：41，自引：14，他引：27
2006年作者曾经按照Sr=400×10~(-6)和Yb=2×10~(-6)作为标志将花岗岩分为埃达克岩、喜马拉雅型花岗岩、浙闽型花岗岩和广西型花岗岩,在浙闽型中又分出南岭型(Sr100×10~(-6)和Yb2×10~(-6)),于是花岗岩被分为5类。Sr=400×10~(-6)和Yb=2×10~(-6)是根据阿留申群岛中的Adak岛的资料得出来的。本文统计了全球花岗岩6000多个数据(其中,埃达克型花岗岩为2810个,喜马拉雅型花岗岩636个,浙闽型花岗岩1183个,南岭型花岗岩1518个,广西型花岗岩142个,总共6289个),统计的结果,各类花岗岩的地球化学特征大致如下:(1)埃达克型花岗岩富Al_2O_3和Sr,贫Y和Yb,具较高和变化的铕异常,绝大多数样品的Sr300×10~(-6),Yb2.5×10~(-6)(当Sr=400×10~(-6)～600×10~(-6)时Yb值最大,Sr超过600×10~(-6),Yb降低至2×10~(-6)),Al_2O_3在14%～18%之间,Eu/Eu~*大多在0.6～1.2范围;(2)喜马拉雅型花岗岩贫Sr和Yb,具中等的Al_2O_3和变化的Eu/Eu~*,Sr300×10~(-6)和Yb2×10~(-6)(少数Sr300×10~(-6)),Al_2O_3为13%～17%,Eu/Eu~*为0.2～1.0;(3)浙闽型花岗岩贫Sr富Yb,Sr在40×10~(-6)～400×10~(-6)之间,Yb1.5×10~(-6),Al_2O_3和Eu/Eu~*的变化类似喜马拉雅型花岗岩,Al_2O_3为12%～17%,Eu/Eu~*为0.4～1.0;(4)南岭型花岗岩以很低的Sr、Al_2O_3和Eu/Eu~*以及很高的Yb而不同于上述各类花岗岩,通常Yb1.5×10~(-6),Sr100×10~(-6)(Yb变化大,绝大多数2×10~(-6);当Yb在2×10~(-6)～8×10~(-6)时,部分样品Sr可100×10~(-6),但很少200×10~(-6));Al_2O_314%,集中在11%～13%之间,Eu/Eu~*0.7,大多0.4;Yb越大,Sr越低,负铕异常越明显。文中讨论了花岗岩Sr-Yb分类的意义,指出本分类适用于产于大陆和海洋的绝大多数中酸性岩浆岩(可能不适用于一部分特别富铁和钾的花岗岩,如具有高Sr和Yb特征的广西型花岗岩)。不同类型的花岗岩主要反映了源区压力的不同,而源区成分、温度、部分熔融程度、水和挥发分的加入以及岩浆混合等的影响可能是次要的。文中指出,该分类的依据、其实质,是熔体与残留相平衡的理论。与浙闽型花岗岩平衡的残留相是斜长石,与喜马拉雅型花岗岩平衡的是斜长石+石榴石,与埃达克型花岗岩平衡的是石榴石,与南岭型花岗岩平衡的是富钙的斜长石。文中指出,加强实验岩石学研究,将年代学和地球化学研究密切结合起来是深化花岗岩研究的关键。 相似文献
9.
Jacob Uzan 《国际地质力学数值与分析法杂志》1992,16(6):453-459
The paper presents an approach for characterizing pavement materials using the modified linear elastic behaviour. The secant modulus of elasticity is expressed in terms of the stress invariants and an expression for the secant Poisson's ratio is derived using path independence of the total work along a closed loading cycle. Triaxial test results of granular base–subbase materials which exhibit strong non-linear behaviour and dilatancy are analysed and presented. The constitutive law is included in a finite element program and results of pavement analyses are discussed. It is found that the secant Poisson's ratio of granular base materials reaches values between 0·6 and 0·7, indicating a volume increase under high stress ratios. The pavement response predicted using the above material characterization is compatible with non-destructive test results. 相似文献
10.
东濮凹陷低渗致密储层的沉积-成岩特征表现为砂层薄、粒度细、沉积非均质性显著;埋藏深度大于3700m,压实作用、晚期自生伊利石-绿泥石和二氧化硅胶结作用强。储层具有小孔极细喉孔隙结构,表面积大,渗透率对围压的敏感性强,地下真实孔隙度和渗透率分别介于10% -< 5% 、0.1×10-3-< 0.001×10-3μm 2.研究认为,东濮凹陷致密砂岩气藏大多产出于盆地次级深洼陷中,具有高压水溶气的成因机制,这是由储层的低渗性、较高的毛细管准数、高束缚水饱和度和高温-高压以及充足-近源的天然气供给等条件所决定的。 相似文献
11.
Jennifer L. Stone‐Sundberg Yunbin Guan Ziyin Sun Troy Ardon 《Geostandards and Geoanalytical Research》2021,45(1):207-221
The attractive physical and chemical properties of corundum lend to this material’s importance in both its natural and synthetic forms. However, much of the quantitative work performed on this material is plagued by unknown inaccuracy as non‐matrix‐matched reference materials are used. To conduct accurate quantitative analysis using SIMS, matrix‐specific relative sensitivity factors (RSFs) were determined for eighteen trace elements in corundum using dose‐verified ion implants. The RSF values ranged from 2.56 × 1022 to 3.29 × 1024 cm‐1 with total combined uncertainty values ranging from 7 to 10%. The RSF values, which are related to ionisation potentials, showed trends consistent with expectations for an insulating oxide. The developed values were applied to calibrate reference materials for LA‐ICP‐MS and to study other natural and synthetic corundum samples. A measurement reference material calibrated for Mg, Si, Ti, V, Fe and Ga produced consistent results over ten sessions in 4 years with relative standard deviations per trace element of 5% or less, confirming the repeatability of our process. A key finding was that calibrating LA‐ICP‐MS with NIST SRM 610 and 612 glasses to analyse corundum resulted in under‐reporting trace elements Be, Ti, V, Fe, Co, Ni and Ga compared with using matrix‐matched reference materials. 相似文献
12.
13.
Rock and flow parameters of three karstic-fissured-porous aquifers in the Krakow-Silesian Triassic formations were measured
using various methods and compared. Though cavern and fissure porosities are shown to be very low (cavern porosity below 0.5%
and fracture porosity below 0.2%), they contribute dominantly to the hydraulic conductivity (from about 1.3×10–6 to about 11×10–6 m/s). Matrix porosity (2–11%) is shown to be the main water reservoir for solute transport and the main or significant contributor
to the specific yield (<2%). Though the matrix porosity is shown to be much larger than the sum of the cavern and fissure
porosities, its contribution to the total hydraulic conductivity is practically negligible (hydraulic conductivity of the
matrix is from about 5×10–11 m/s to about 2×10–8 m/s). On the other hand, the matrix porosity (for neglected cavern and fissure porosities) when combined with tracer ages
(or mean travel times) is shown to yield proper values of the hydraulic conductivity (K) by applying the following formula:
K≅(matrix porosity×mean travel distance)/(mean hydraulic gradient×mean tracer age). Confirming earlier findings of the authors,
this equation is shown to be of great practical importance because matrix porosity is easily measured in the laboratory on
rock samples, whereas cavern and fracture porosities usually remain unmeasurable.
Received: 21 February 1997 · Accepted: 13 May 1997 相似文献
14.
赞皇杂岩中的菅等花岗岩体位于临城县西北,主要由钾长花岗岩和二长花岗岩组成,偶见暗色包体。菅等花岗岩SHRIMP锆石U Pb年龄为（2 490±13） Ma。岩石具有高硅（SiO2 743%～754%）、高钾（K2O 576%～937%）、富碱（ALK 616%～951%）、贫钙（CaO 014%～081%）、低镁、铁（MgO 002%～049%,TFeO 026%～105%）和钛（TiO2 004%～015%）的特征,A/CNK=097～107,为弱过铝质的钾玄岩系列。岩石的稀土总量较低（ΣREE=（1207～16038）×10-6）,轻稀土相对富集,Eu异常变化较大（Eu/Eu*=046～197）。岩石富Rb、Ba和Th等元素,贫Sr、Zr、Nb、Y、Yb等元素,具有较高Rb/Sr和Rb/Ba值以及较低的Y/Nb值。菅等花岗岩具有正的εNd(t)值（285～366）,两阶段Nd模式年龄TDM2集中于255～264 Ga。石英闪长岩包体SHRIMP锆石U Pb年龄为（2 506±13） Ma,高铝（Al2O3 1716%）、富钙（CaO 434%）、高钠（Na2O 447%）、富铁（TFeO 526%）,高Rb、高Sr、高Zr,稀土总量较高（ΣREE=21282×10-6）,有弱的负Eu异常（Eu /Eu*=083）,具TTG岩类的特征;该包体岩石具有正的εNd(t)值（305）,两阶段Nd模式年龄TDM2为263 Ga。这些特征显示菅等花岗岩具有同碰撞和后碰撞的S型花岗岩的特征,为新生地壳在由挤压向伸展转换的构造背景下部分熔融所形成,石英闪长质包体为源区残留的岩石。这期钾质花岗岩的形成,标志着华北克拉通太古宙末期岩浆事件的结束以及稳定陆壳的形成。 相似文献
15.
A capacitance micrometer has been developed for the measurement of thermal expansions of small crystals over moderate temperature ranges (approximately 100 K above laboratory temperature). Linear coefficients are obtained to ±0.5×10?6 K?1 and volume coefficients to ±1.5×10?6 K?1. New values are reported for 13 materials, obtained as crystals down to 1 mm in size. For many of these we obtained satisfactory agreement with earlier data, but exceptions are zircon (volume coefficient 6.6±1.6×10?6 K?1, compared with earlier values up to 21×10?6 K?1) and strontium fluoride (volume coefficient 57.9±2.2×10?6 K?1, compared with 42 to 49×10?6 K?1). The new data are combined with values of incompressibility, density and specific heat to obtain new values of Grüneisen's ratio. 相似文献
16.
通过采集重庆市典型农业区南川区8496件表层土壤样品,测定土壤锗及其他元素的含量,对锗含量特征及其影响因素进行分析探讨.研究结果表明：南川区土壤锗含量变化范围为0.13×10-6~13.59×10-6,平均值为1.54×10-6,高于重庆市"一小时经济圈"和重庆紫色土壤中锗的平均含量.研究区富锗（1.4×10-6以上）土壤面积达1 559.8 km2,主要分布在研究区南部.南川区高锗土壤主要分布在二叠系上统吴家坪组、长兴组和三叠系下统大冶组、嘉陵江组.土壤锗含量主要受成土母质控制,与土壤有机质呈显著正相关关系,与8项重金属元素存在伴生关系.中部高值区受密集的煤矿和人为影响较大. 相似文献
17.
Combined Separation of Cu,Fe and Zn from Rock Matrices and Improved Analytical Protocols for Stable Isotope Determination 总被引：3，自引：0，他引：3 
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下载免费PDF全文 Paolo A. Sossi Galen P. Halverson Oliver Nebel Stephen M. Eggins 《Geostandards and Geoanalytical Research》2015,39(2):129-149
Isotope ratios of heavy elements vary on the 1/10000 level in high temperature materials, providing a fingerprint of the processes behind their origin. Ensuring that the measured isotope ratio is precise and accurate depends on employing an efficient chemical purification technique and optimised analytical protocols. Exploiting the disparate speciation of Cu, Fe and Zn in HCl and HNO3, an anion exchange chromatography procedure using AG1‐×8 (200–400 mesh) and 0.4 × 7 cm Teflon columns was developed to separate them from each other and matrix elements in felsic rocks, basalts, peridotites and meteorites. It required only one pass through the resin to produce a quantitative and pure isolate, minimising preparation time, reagent consumption and total analytical blanks. A ThermoFinnigan Neptune Plus MC‐ICP‐MS with calibrator‐sample bracketing and an external element spike was used to correct for mass bias. Nickel was the external element in Cu and Fe measurements, while Cu corrected Zn isotopes. These corrections were made assuming that the mass bias for the spike and analyte element was identical, and it is shown that this did not introduce any artificial bias. Measurement reproducibilities were ± 0.03‰, ± 0.04‰ and ± 0.06‰ (2s) for δ57Fe, δ65Cu and δ66Zn, respectively. 相似文献
18.
Distribution of heavy metals in soils of Port Harcourt and its environs,Niger Delta,Nigeria 总被引：1，自引：0，他引：1
Geochemical evaluation of the distribution of heavy metals in soils of Port Harcourt and its environs in the Niger Delta region is presented in respect of anthropogenic factor and index of geoaccumulation. Sixteen (16) soil samples were collected from two horizons (0-10 cm and 100 cm) from the various grids and analyzed. The geo-chemical analyses showed the vertical and horizontal distributions of heavy metals. The results showed the ranges of the metals determined as follows: Pb (6.86-2.49)×10-6, with an average of 4.63×10-6; Cd (0.05-0.00)×10-6, with an average of 0.02×10-6, As (0.01-0.00)×10-6, with an average of 0.00×10-6. Cu (15.36-10.80) ×10-6, with an average of 13.36×10-6, and V (1.36-0.20)×10-6, with an average of 0.94×10-6. Quantification of the degree of pollution was carried out using anthropogenic factor (AF) and index of geoaccumulation (Igeo). The Igeo values of 0.06, 0.02 and 0.00 for Pb, Cd and As, respectively indicate low-level contamination while Zn (1.14) and V (1.40) show me-dium-level contamination. The sources of contamination are attributed to urbanized anthropogenic activities. The majority of the samples analyzed show that the AF values are less than 1 with the exception of vanadium (V) whose AF values range from 2.73 to 13.60×10-6. Vanadium is more enriched than As, Cd, Pb, and Cu. The order of degrees of anthropogenic contamination and index of geoaccumulation in the soil is V >Zn >Pb >Cu >Cd >AS. Metals were retained near the top soil and their concentrations in the deepest horizons were lower and normal for uncontaminated soils. Metal concentrations in the top soil horizons were significantly related to distance from the industrial and hu-man activities. 相似文献
19.
江西城门山铜矿铼-锇同位素年龄研究 总被引：33，自引：3，他引：33
城门山铜矿中，侵入到花岗闪长岩中的石英斑岩，其Ｒｅ－Ｏｓ法同位素测年结果为１４０×１０６ａ，进而确定了该区二次岩浆侵入活动时间相隔约１０×１０６ａ，在这期间内，岩浆由中酸性演变为酸性；与其相应的成矿作用则从夕卡岩型铜、硫矿化演变为细脉浸染型铜、金矿化，构成了一个演化序列。在细脉浸染型辉钼矿化作用中，石英细脉中辉钼矿比石英斑岩中浸染状辉钼矿形成略早，二者在空间上呈正消长，而整个成矿过程大约经历了４×１０６～３×１０６ａ。 相似文献
20.
The abundances of 29 elements, including nine REE (La, Ce, Nd, Sm, Eu, Tb, Dy, Yb and Lu), have been determined by instrumental neutron activation analysis in 33 tholeiitic basalts from Mauna Loa, Kohala, Mauna Kea, Lanai and Koolau. These data have been combined with data provided by A. V. Murali et al. on seven basalts from Kilauea for geochemical evaluation.Partial melting models based on the partitioning of the REE and Sc suggest that these basalts can be produced from three distinct source compositions. Thus, the basalts from Mauna Kea, Kohala and Kilauea are generated by 2–10% partial melting of similar source materials in the compositional range 82 ± 4% olivine plus orthopyroxene (ol + opx), 14 ± 3% clinopyroxene (cpx) and 4 ± 1% garnet (gar). Similar amounts of melting of source materials having 74 ± 6% ol + opx, 21 ± 5% cpx and 5 ± 1% gar produce the basalts of Mauna Loa and Lanai. A source material composed of 86 ± 4% ol + opx, 11 ± 2% cpx and 3 ± 1% gar is proposed for the generation of basalts from Koolau.The olivine-crystallization model suggested here requires absolute REE abundances in the preferred Mauna Kea, Kohala and Kilauea source to range from 1.1× (times chondrite) for the LREE (La) to about 1.3× for the HREE; in the Mauna Loa and Lanai source, La is about 1.0× and the HREE are about 1.6×; and in the Koolau source, La is ~0.7× and the HREE are ~0.9×. 相似文献