高温熔融研制岩石标准玻璃方法初步研究:以玄武岩为例

探索了利用高温炉合成玄武岩玻璃制作原位微区主微量元素含量分析的标准物质的实验条件.选取玄武岩标准物质GBW07105(GSR-3)进行高温熔融、淬火实验研究,获得玄武岩玻璃,为合成其他地质样品微区分析标准参考物质的研制提供了参考方法.用激光剥蚀-四极杆等离子体质谱(LA-Q-ICPMS)对样品微区46个主元素和微量元素...     

山东省临朐—沂水地区橄榄玄武岩地质特征及开发利用研究

玄武岩纤维是国际上重点发展的新材料之一,附加价值极高。以天然玄武岩拉制的连续纤维是一种新型无机环保绿色高性能纤维材料,具有强度高,电绝缘、耐腐蚀、耐高温等多种优异性能。笔者等通过对山东省临朐—沂水地区橄榄玄武岩地质特征、岩相学特征及岩石地球化学特征进行分析研究,发现产出于中新世临朐群牛山组偏基性火山岩的致密块状橄榄玄武岩,是拉丝纤维用的理想原矿石。笔者等梳理了国内部分生产企业和学者研究关于天然玄武岩成功拉丝的研究进展,分析研究了山东省临朐—沂水地区橄榄玄武岩影响连续纤维用玄武岩矿拉丝性能的七大参数指标,结果表明,研究区橄榄玄武岩除酸度系数偏低外,各项参数均符合连续拉丝纤维生产各项指标,可为后续开展纤维用玄武岩地质调查工作提供参考,助力资源的开发利用研究。     

山东省临朐—沂水地区橄榄玄武岩地质特征及开发利用研究

玄武岩纤维是国际上重点发展的新材料之一,附加价值极高。以天然玄武岩拉制的连续纤维是一种新型无机环保绿色高性能纤维材料,具有强度高,电绝缘、耐腐蚀、耐高温等多种优异性能。笔者等通过对山东省临朐—沂水地区橄榄玄武岩地质特征、岩相学特征及岩石地球化学特征进行分析研究,发现产出于中新世临朐群牛山组偏基性火山岩的致密块状橄榄玄武岩,是拉丝纤维用的理想原矿石。笔者等梳理了国内部分生产企业和学者研究关于天然玄武岩成功拉丝的研究进展,分析研究了山东省临朐—沂水地区橄榄玄武岩影响连续纤维用玄武岩矿拉丝性能的七大参数指标,结果表明,研究区橄榄玄武岩除酸度系数偏低外,各项参数均符合连续拉丝纤维生产各项指标,可为后续开展纤维用玄武岩地质调查工作提供参考,助力资源的开发利用研究。     

A theoretical consideration of the kinetics of calcite recrystallization produced by two basalt dykes in Co. Antrim,Northern Ireland

The size of crystallites of calcite in the vicinity of a basalt intrusion systematically diminishes with increasing distance from the heat source. A theoretical analysis of the kinetics of recrystallization leads to the conclusion that the particle size change involved the nucleation and growth of new calcite crystallites. The theory of reaction rates, as applied to the natural system, is discussed with reference to the inherent assumptions, inaccuracies and limitations.     

Studies of melt inclusions in some basalts from eastern China

Cenozoic basalts widespread in eastern China constitute an important sector of the circum-Pacific Cenozoic basalt belt. Basalt samples were collected from Wudalianchi (Heilongjiang Province), Nushan (Anhui Province), Fangshan (Jiangsu Province), Zhuji (Zhejiang Province), and Mingxi(Fujian Province). These basalts, for the most part, belong to the alkali basaltic series, and partly to tholeiites. A variety of inclusions commonly occurs in the rock-forming minerals of these basalts. The physicochemical conditions of basalt formation in different areas have been reviewed in special reference to the inclusion data. Our studies have shown that there is a close relationship between the features of the inclusions and the physicochemical conditions of basalt formation, which can, therefore, be regarded as a guide to the mechanism of basaltic petrogenesis. The results of research in this aspect are presented in the present paper.     

辽宁宽甸黄椅山玄武岩中地幔岩捕虏体的REE 及 Sr、Nd 同位素地球化学

报道了黄椅山玄武岩中三类地幔岩捕虏体的 REE 丰度和 Sr、Nd 同位素组成。研究分析认为:尖晶石二辉橄榄岩是地幔岩经不同程度部分熔融的残留体;角闪石二辉橄榄岩系地幔交代作用的结果;石榴石二辉岩是在地幔条件下基性岩浆的分凝体。上述捕虏体均与寄主玄武岩无成因关系。地幔岩捕虏体的 Sm-Nd 计时获得741Ma 和78Ma 两条参考等时线,它们分别相当于晚元古代和晚中生代的地幔事件。     

辽宁宽甸黄椅山玄武岩中地幔岩捕虏体的REE 及 Sr、Nd 同位素地球化学

 报道了黄椅山玄武岩中三类地幔岩捕虏体的 REE 丰度和 Sr、Nd 同位素组成。研究分析认为:尖晶石二辉橄榄岩是地幔岩经不同程度部分熔融的残留体;角闪石二辉橄榄岩系地幔交代作用的结果;石榴石二辉岩是在地幔条件下基性岩浆的分凝体。上述捕虏体均与寄主玄武岩无成因关系。地幔岩捕虏体的 Sm-Nd 计时获得741Ma 和78Ma 两条参考等时线,它们分别相当于晚元古代和晚中生代的地幔事件。     

辽河油田东部凹陷玄武岩测井特征分析

针对辽河油田东部凹陷地区复杂火成岩岩性中玄武岩的测井特征,根据东部凹陷的测井数据及取芯段的薄片识别,共找到4种不同类型的玄武岩地层,分两组进行对比分析。第一组:气孔玄武岩、角砾化玄武岩;第二组:玄武岩、含油水层的玄武岩。利用玄武岩地层对应数据制作测井响应统计表,对比不同类型测井参数的差别制作交会图,得到角砾化玄武岩相对气孔玄武岩有较高的自然电位值,含油水层的玄武岩相对玄武岩有较高自然伽马值及中子值等特征。分析原因为气孔玄武岩及角砾化玄武岩孔隙裂缝发育,密度较低,黏土矿物充填角砾化玄武岩孔隙使自然电位值相对较高;含油水层的玄武岩中大量氢元素使中子值及自然伽马值相对玄武岩有所增加。     

La-Ce法岩石标准物质和Ce同位素标准溶液研制

报道了La-Ce法岩石标准物质的研制结果。标准物质选自峨眉山玄武岩中的新鲜微晶玄武岩（编号EQB）,具有间隐结构,矿物组成相对均一。岩石经粉碎和均一化加工,成为粉末后分装成1000小瓶。经均匀性和稳定性检验合格后,对该岩石标准物质的Ce同位素比值和La、Ce元素含量进行了测定和定值统计,其结果分别表示为：138Ce／142Ce=0．0225755±0．0000003,Ce=（117．4±1．3）μg／g,La=（55．8±0．9）μg／g。对二氧化铈化学试剂进行了溶液制备,以用于Ce同位素分析仪器标准物质。标准溶液编号为CBRICeO2,其138Ce／142Ce比值的测定统计值为0．0225748±0．0000006。为检验所制标准物质分析数据的准确度,对国际标样进行了比对测量,其中JMC304标准溶液的138Ce／142Ce比值测定结果为0．0225762±0．0000015,USGS玄武岩标样BCR-2的La和Ce元素含量测定结果分别为（25．2±0．6）μg／g（2σ）和（54．2±0．8）μg／g（2σ）,所获数值与文献报道值或证书值在误差范围内相符。     

Geochemical Variation in the Greenstones of S.W. England

The characteristic rocks of the Upper Palaeozoic greenstonesof S.W. England are intrusive dolerites and extrusive basicpillow lavas with minor intermediate volcanics and ultrabasics(picrites). Pyroclastics are represented by keratophyric andbasic tuffs. The intrusive greenstones show varying degrees of alteration(spilitization) from a primary ilmenite-plagioclase-clinopyroxene?olivineassemblage to a hydrous low-grade spilite (or meta-dolerite)assemblage composed of variable proportions of albite, chlorite,epidote, calcite, and amphibole. Based on the distribution of elements little affected by secondaryprocesses (Ti, P, Y, Nb, and Zn), the intrusive greenstonescontain representatives of both the alkali olivine basalt andtholeiitic basalt magma series. Magmatic differentiation isgenerally minimal with the Devonian alkali basalt greenstonesbeing principally basaltic, while some of the Carboniferousalkali basalt greenstones tend towards mugearitic compositions.No intrusive acid differentiates have yet been reported. Apart from differences of magma type and minor differentiation,low-grade alteration or ‘spilitization’ has alsogoverned the geochemical variation seen in the greenstones.Spilitization caused (a) local redistribution of principallyCa (forming epidote-rich and calcite-rich patches) and Mg (formingchlorite-rich patches), together with their respective coherenttrace elements, and (b) the variable, but often limited, lossof Ca, Sr, K, Rb, and Ba from many bodies, together with a gainin Na and H₂O. Progressive hydration, however, caused a decreasein the oxidation ratio—a feature found to be common inmany spilitic suites and mainly governed by the relative distributionof chlorite versus epidote.     

高精度测量岩石样品Ce同位素组成的TIMS方法

介绍了对岩石样品的Ce同位素组成进行高精度测量的TIMS方法.采用α-羟基异丁酸(α-HIBA) 离子交换法分离和纯化岩石样品中的La、Ce元素, Ce同位素组成和La、Ce含量测定在Triton热电离质谱仪上完成.质谱标样JMC304的138Ce/142Ce比值统计值为0.0225762±0.0000015, 与大部分文献值一致.应用该方法对USGS玄武岩标样BCR-2和峨眉山玄武岩EQB的138Ce/142Ce比值和La、Ce含量进行了分析, 其结果分别为: 0.0225572±0.0000010、25.2±0.3μg/g、55.8±0.9μg/g和0.0225755±0.0000003、54.2±0.4μg/g、117.4±1.3μg/g.BCR-2的La、Ce含量测定结果与其证书值在误差范围内一致, 其分析精度为0.001%~0.005%.所有样品的140Ce/142Ce比值测定结果统计值为7.9439±0.0002, 介于文献最低值7.941与最高值7.947之间, 可能代表了该比值的最佳估计值.      

攀西地区铅锌成矿地质背景——兼论峨眉山玄武岩与铅锌成矿作用

攀西成矿带具有独特的大地构造位置、复杂的地质演化和丰富的矿产资源。前人工作已基本查明了区内铅锌成矿地质背景,但关于峨眉山玄武岩与铅锌成矿作用之间的关系,仍有较多认识分歧。笔者通过综合分析前人在地质、地球化学、矿产资源等方面的研究成果,认为与成矿有关的是峨眉山玄武岩之后的印支晚期和燕山期的两次相对较弱的构造岩浆侵入作用,峨眉山玄武岩本身不提供成矿物质、流体和热动力,但其形成厚大的盖层空间使其后期成矿流体均得以保存下来富集成矿,具有重大贡献。提出该区铅锌找矿的三条件：目前（或曾经）被峨眉山玄武岩覆盖、地层为前二叠系碳酸盐岩、后期（印支晚期-燕山期）构造发育。     

柱状节理玄武岩岩体结构与结构面的分形研究

峨嵋山柱状节理玄武岩是西南地区分布的主要岩类。柱状节理玄武岩的原生建造、构造作用和风化卸荷对岩体结构和工程性状有较大的影响。节理裂隙影响岩体结构并劣化岩体完整性,分维数D能客观地表现岩体完整性特征,因而分析讨论柱状节理岩体节理面的分形特征,可以深层次的反映柱状节理岩体的工程地质特点。     

四川盆地华蓥山峨眉玄武岩地球化学特征及其成因分析

四川盆地华蓥山玄武岩出露于茅口组顶部,夹于龙潭组底部的杂色泥岩、页岩之间,岩性为灰黑色粗玄岩,底部致密块状,顶部见气孔—杏仁状构造。TAS图解显示玄武岩属于碱性与偏碱性过渡带上的拉斑玄武岩系列,TiO2含量介于2.92%~3.63%之间,Ti/Y值为465~567,属于高钛玄武岩(HT)。岩石LREE/HREE=3.25~3.96,轻稀土略富集,具有右倾平滑型稀土分配模式。华蓥山玄武岩与云南宾川,贵州赫章等地峨眉山玄武岩的地球化学特征相似,反映了相同的幔源性质。结合野外地质特征,认为华蓥山玄武岩应属峨眉地幔柱的一部分,是沿着华蓥山基底断裂发生裂隙式喷发的产物。研究区的高钛玄武岩Ce/Yb介于22.65~27.93,与前人报道的高钛玄武岩Ce/Yb比值范围基本一致,处于石榴石稳定区与尖晶石稳定区的过渡带,Th/Ta、Nb/U、La/Ta等比值反映出岩石受壳源物质的混染程度很低,可能是地幔柱轴部的产物。     

内蒙古贺根山蛇绿岩中玄武岩锆石U-Pb年龄、地球化学特征及其地质意义

贺根山蛇绿岩（套）中发育有气孔杏仁状玄武岩,为蛇绿岩套的组成部分。通过对其锆石U-Pb测年,其加权平均年龄为395.9 Ma±3.0 Ma,结合区域地质背景,认为贺根山蛇绿岩（套）形成时代为中泥盆世—早石炭世。玄武岩为亚碱性系列,具有LREE亏损、类似N-MORB的稀土配分模式,同时具备大洋玄武岩和岛弧玄武岩特征,认为贺根山蛇绿岩（套）应形成于弧后盆地;通过与现代典型Mariana洋内弧后盆地和Okinawa陆缘弧后盆地的玄武岩以及同属中亚造山带的新疆库尔提洋内弧后盆地蛇绿岩对比,发现贺根山玄武岩同Mariana玄武岩和库尔提蛇绿岩更加类似,由此认为贺根山蛇绿岩（套）很可能形成于洋内弧后盆地环境,而非大陆边缘弧后盆地环境。     

四川龙舟山玄武岩的岩石学特征及成因探讨

龙舟山玄武岩一直被认为是与P_2峨眉山玄武岩相当的溢流玄武岩。笔者的观察和研究表明:只有龙舟山玄武岩的上部才相当于P_2峨眉山玄武岩;下部则具有分期复杂的特点。本区玄武岩的演化具典型的板内裂谷玄武岩演化特点,玄武岩的演化同攀西裂谷的构造演化是一致的。     

敦化地区玄武岩的开发利用前景

本文介绍了敦化地区玄武岩的分布范围、厚度和目前开发利用状况。玄武岩除了做石材外,还有一个新的用途——生产玄武岩纤维,它用途广泛,性能优良。国外已开发利用多年,我国刚刚起步。在敦化地区无论是开采玄武岩石材还是生产玄武岩纤维其前景都十分广阔。     

Chemical evolution of the Mt. Hekla,Iceland, groundwaters: A natural analogue for CO2 sequestration in basaltic rocks

A detailed study of the chemical composition of the groundwater surrounding the Mt. Hekla volcano in south Iceland was performed to assess fluid evolution and toxic metal mobility during CO₂-rich fluid basalt interaction. These fluids provide a natural analogue for evaluating the consequences of CO₂ sequestration in basalt. The concentration of dissolved inorganic C in these groundwaters decreases from 3.88 to 0.746 mmol/kg with increasing basalt dissolution while the pH increases from 6.9 to 9.2. This observation provides direct evidence of the potential for basalt dissolution to sequester CO₂. Reaction path calculations suggest that dolomite and calcite precipitation is largely responsible for this drop in groundwater dissolved C concentration. The concentrations of toxic metal(loid)s in the waters are low, for example the maximum measured concentrations of Cd, As and Pb were 0.09, 22.8 and 0.06 nmol/kg, respectively. Reaction path modelling indicates that although many toxic metals may be initially liberated by the dissolution of basalt by acidic CO₂-rich solutions, these metals are reincorporated into solid phases as the groundwaters are neutralized by continued basalt dissolution. The identity of the secondary toxic metal bearing phases depends on the metal. For example, calculations suggest that Sr and Ba are incorporated into carbonates, while Pb, Zn and Cd are incorporated into Fe (oxy)hydroxide phases.     

The geologic history of the Caribbean-Cocos plate boundary with special reference to the Nicoya ophiolite complex (Costa Rica) and D.S.D.P. results (Legs 67 and 84 off Guatemala): A synthesis

The Pre-Upper Senonian basement of Costa Rica crops out in the Santa Elena and Nicoya peninsulas. From south to north and from base to top the basement includes: the Esperanza, Matapalo and Santa Elena units. The Esperanza unit is Albian-Santonian in age and consists mainly of pillow basalt and massive basalt flows. The Matapalo unit includes Callovian to Cenomanian radiolarite and includes massive basalt flows, basalt, and dolerite basement. The Santa Elena unit contains ultramafic and mafic rocks in which harzburgite is the major component. The most important tectonic features of the Nicoya Complex are the large Santa Elena and Matapalo nappes. Nappe emplacement was from north to south during upper Santonian time. The sedimentary cover of the Nicoya Complex comprises:

1. (1) the Campanian El Viejo Formation that consists of shallow-water sediments in the north (Santa Elena Peninsula) and the Campanian-Maastrichtian Sabana Grande Formation of deep-water origin in the South (Nicoya Peninsula);

2. (2) Paleocene strata indicating deposition in a deep-water environment comprises the Rivas, Las Palmas and Samara Formations;

3. (3) a post-upper Eocene (?) sequence that consists of the shallow-water Barra Honda and Montezuma Formations.

Two unconformities are significant geological features of the upper-Senonian to Tertiary history of Costa Rica. The lower one is at the base of the Sabana Grande Formation and marks a major change in the geologic conditions (basalt is scarce in the Campanian-Tertiary series); the upper unconformity at the base of the Barra Honda and Montezuma Formations is not as major as the lower one. During post-Campanian time, normal faulting occurred in two stages separated by a strong erosional phase.The geology of the landward slope of the adjacent Middle America Trench is outlined by interpreting multifold seismic reflection records off the west coast of Costa Rica and the DSDP Legs 67 and 84 transects off Guatemala. The western Caribbean plate boundary may have been under extensional stress for the last 75 m.y. The strong landward-dipping reflectors of the Middle America Trench landward slope off Guatemala could be equivalent to the on-land pre-Campanian overthrusts of Costa Rica. The available data are consistent with the Convergent Extensional margin concept.     

四川雷波峨眉山玄武岩岩石学及地球化学特征

以剖面测量及野外系统观察、显微镜下及地球化学研究为基础,认为雷波地区峨眉山玄武岩主要具有以下特点:①岩石类型主要为致密块状玄武岩、斑状玄武岩、杏仁状玄武岩,发育柱状节理,为典型陆相喷发玄武岩;②岩石化学分类为碱性玄武岩,具高钛特征,为板内拉张玄武岩;③玄武岩经历了相似的岩浆演化和结晶分异,形成深度大,起源于富集地幔源,是地幔柱作用的产物;④玄武岩是攀西裂谷拉张作用的产物,无爆发角砾岩相,主要为喷溢-溢流相,可能属攀西裂谷的边缘相带。