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碾子山晶洞碱性花岗岩矿物-水氧同位素交换反应动力学 总被引：4，自引：0，他引：4
对黑龙江碾子山碱性花岗岩的全岩及其主要单矿物进行了氧同位素分析，结果表明，全岩和单矿物不仅δ^18O 值变化范围较大（全岩－2．4－2．0‰，石英0．0－5．8‰，碱性长石－3．8－0．1‰，磁铁矿－8．5－1．0‰），而且强烈亏损^18O。共生矿物之间表现出明显不平衡的氧同位素分馏特征，指示在花岗岩侵位之后与水之间发生了同位素交换，根据锆石和现代大气降水的氧同位素组成，对岩石与外来流体的δ^18O值进行了估计，多维矿水－岩反应时限约为0．3－3Ma，水／岩比（氧摩尔比）介于0．11－1．02之间。水－岩反应温度较高（约400度）和反应时间较长是导致石英δ^18O值降低的主要原因。 相似文献
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苏州花岗岩的氧同位素研究 总被引：3，自引：0，他引：3
本文根据钻孔样品对苏州花岗岩主侵入阶段岩石作了较详细的氧同位素研究。内部相岩石全岩、石英与长石的δ18O值变化小,石英和长石的氧同位素组成处于同位素平衡状态,在δ18OQ－δ18Of图上分布于一个很小区域内,表明内部相岩石并未受到雨水热液作用影响;而边缘相岩石的全岩δ18O变化明显,石英和长石的氧同位素组成处于极端不平衡状态,在δ18OQ－δ18Of图上,呈近乎垂直状态分布,表明已受到雨水热液作用的显著影响。强烈的水一岩交换作用还导致了Nb、Ta、Zr、Hf、Th等稀有元素在边缘相的矿化作用。本文还对苏州花岗岩的源区物质特征作了讨论。 相似文献
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新疆阿尔泰阿拉尔花岗岩多维矿物相-水氧同位素交换反应动力学 总被引：6，自引：0，他引：6
新疆阿尔泰阿拉尔花岗岩中共生石英、长石、黑云母的δ~(18)O值具有宽广的变化范围,3者表现出显著的~(18)O/~(16)O不平衡关系,尤其是石英、长石具有倒转△~(18)O_(石英-长石)关系(△~(18)O_(石英-长石)<0)。上述关系清楚地表明在花岗岩-水之间发生了~(18)O/~(16)O交换反应。根据质量平衡约束关系对岩石与外来流体的初始δ~(18)O值作了估计。由于花岗岩的初始δ~(18)O值被大大地改变了,简单运用全岩或者单矿物样品的δ~(18)O值判断岩浆来源的方法是不可靠的。水-岩之间的~(18)O/~(16)O交换反应并不伴随着岩石矿物学上的强烈蚀变效应,这种脱藕关系暗示着交换反应发生于较高温度即岩浆次固相-岩浆期后冷凝过程中。交换机制主要为扩散控制。定量模拟表明:阿拉尔岩体具有高流体流动速率(3×10~(-14)mol/s)、长水-岩反应时限(0.8-6Ma)、高水/岩值(0.79-6.14)。在造山带岩浆弧环境的中部地壳层次下,变质流体流动和环流是非常强烈的。 相似文献
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华南钨矿床黑钨矿的氧同位素研究 总被引：4，自引：0，他引：4
根据华南地区、横断山脉和秦岭地区30多个钨矿床，133个黑钨矿矿物氧同位素组成测定，结合其他同位素资料，将黑钨矿矿石的成因划分为：再平衡岩浆水、大气降水、变质水及混合水四种类型。前两者黑钨矿的δ^18O值分别为 5%左右和-1‰左右，而后两者则在前两者之间。根据共生石英和黑钨矿的δ^18O值，结合温度资料，获得石英-黑钨矿和黑钨矿-水的氧同位素分馏温度校正曲线及其相应方程式。 相似文献
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空树河组是滇西腾冲地块北部的石碳－二叠纪冈瓦纳相沉积。菱铁矿结核见于该组顶部的黑色泥岩中。将一个结核通过中心切开，在切面上由中心向边缘用牙钻等间隔提取10个样品。同位素测试结果显示，δ^13C自中心向边缘逐渐由－8．09％减为－16．12％，最外一个样例外（－15．39‰），而δ^18O自中心向边缘逐渐由－10．64‰增加为0‰左右。δ^13C的变化情况表明，菱铁矿结核可能形成于硫酸盐还原带。在解释δ^18o的变化情况时，推测在结核开始生长时可能有δ^18O亏损的大气降水掺入，随着埋藏深度的逐渐加大，孔隙水的O同位素逐渐趋近正常海水的值（0‰）。 相似文献
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中国大陆科学钻探（CCSD）HP-UHP变质岩中石英脉流体包裹体δD-δ^18O同位素组成及其意义 总被引：2，自引：4，他引：2
流体包裹体δD-δ^18O同位素测定显示CCSD石英脉具有较稳定的氢同位素（8D=-97‰～-69‰）和相对较低且变化较大的氧同位素组成，其矿物δ^18O为-1．9‰-9．6‰，相应流体的δ^18O为-11．66‰～0．93‰，说明其变质岩围岩在板块俯冲前曾在地表与大气降水发生过程度不同的水／岩反应，而石英脉继承了其各自寄主变质岩的δ^18O组成；在CCSD纵向上，石英脉的δ^18O同位素组成出现“∑”型变化，分别在900m～1500m和2700m出现极低值，而在1770m和4000m出现高正值，说明CCSD变质岩原岩在俯冲前与大气降水间的水／岩反应受到局部侵入的岩浆岩带来的高温和构造空间的控制；CCSD中石英脉δ^18O在纵向上的变化基本同步于其寄主围岩变质矿物的δ^18O组成变化，说明石英脉与其他变质矿物一样．也经历了HP，甚至UHP变质，但其主体应形成于板块折返过程中HP-UHP岩石的减压重结晶及退变质；CCSD石英脉、东海地表石英脉或水晶矿的δD-δ^18O同位素值分布的不均一性，说明HP-UHIP岩石在板块折返及其后退变质中释放出的流体活动范围有限，没有经历大规模的流动或迁移。东海水晶的流体包裹体δD-δ^18O组成与CCSD石英脉相似，显示它们的成因基本一致，主要形成于晚三叠世板块折返过程。 相似文献
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成都地区大气降水稳定同位素组成反应的气候特征 总被引：4，自引：0，他引：4
分析了1986-1998年成都地区大气降水的稳定同位素组成。夏季降水的δD和δ^18O值比冬季降水轻,反映了季风气候的降水特点。成都地区的大气降水线方程是：δD=1．42＋7．530δ^18O,与全球和中国降水线方程相比,表明了成都地区的蒸发程度稍大于降雨,说明成都地区大气降水的不平衡蒸发程度弱,反映了海洋性气候特征。成都地区大气降水δ^18O与降雨量、温度和水汽压之间都是负相关关系。但是降雨量对大气降水δ^18O的影响最大。 相似文献
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Multicomponent exchange and diffusion in silicates 总被引：1，自引：0，他引：1
Antonio C. Lasaga 《Geochimica et cosmochimica acta》1979,43(4):455-469
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M.A. Kessick 《International Journal of Mineral Processing》1980,6(4):277-283
Two clay gel systems, a sample of settled oil sands clay tailings and a montmorillonite gel, were effectively dewatered by conversion to calcium forms by ion exchange, followed by freezing and thawing in the case of the montmorillonite gel and by either centrifugation or freezing and thawing in the case of the oil sands slime. Maximum dewatering was shown to be associated with complete conversion to the calcium forms. The implications of caustic recovery during the process are discussed. 相似文献
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大气、海洋与固体地球的能量交换 总被引：9，自引：0，他引：9
通过对南极气温资料、南极臭氧资料、环南极海冰资料、太平洋海温资料、地球自转速度变化资料、厄尔尼诺和拉尼娜资料的模拟验证，发现厄尔尼诺事件发生与德雷克海峡海冰减少在时间上有一一对应关系。南极半岛海冰减少是太平洋环流速度减慢的原因，德雷克海峡的海冰起重要作用。大气、海洋与固体地球的角动量交换在南、北半球有不同的形式。强震起源于海平面振荡。 相似文献
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During the 1999–2002 water years, a hydrogeological research project was carried out on the unconfined aquifer of Trifilia in the Peloponnese. Seawater intrusion due to overpumping, and intensive use of fertilizers caused the groundwater quality degradation that is a typical case for the coastal aquifers in Greece. Isopiezometric maps along with ion distribution balances, ion distribution maps and factor analysis indicate the existence of three zones of groundwater quality. In the first zone of saline water, a cation exchange process between the Ca2+ of sediments and the Na+ of groundwater contribute to the formation of the water type Na+-Ca2+-Cl–. In the second zone, which is considered as a transition zone, dominate the Ca2+-Na+-HCO3–-Cl– water type. In the third zone of Ca2+-HCO3–-SO42– water type, relationships among Ca2+, SO42–, NO3– and NH4 can be attributed to the dissociation of ammonium nitrate and sulfate fertilizers on one hand, and Ca2+ derivation from cation exchange processes between water, rocks and clay minerals, such as smectite and illite, on the other. 相似文献
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G. R. T. JENKIN C. M. FARROW A. E. FALLICK D. HIGGINS 《Journal of Metamorphic Geology》1994,12(3):221-235
Retrograde exchange of oxygen isotopes between minerals in igneous and metamorphic rocks by means of diffusion is explored using a finite difference computer model, which predicts both the zonation profile of δ18 O within grains, and the bulk δ18 O value of each mineral in the rock. Apparent oxygen isotope equilibrium temperatures that would be observed in these rocks are calculated from the δ18 O values of each mineral pair within the rock. In systems which cool linearly from a sufficiently high temperature or at a low enough cooling rate, such that the final oxygen isotope values are not dependent upon the initial oxygen isotope values ('slow cooling'), the apparent oxygen isotope temperature derived for a rock composed of a single mineral pair can be shown to be simply related to the Dodson closure temperatures ( T c ) for the two phases and the mode of the rock. Adding a third phase into a system which undergoes 'slow' cooling will cause the apparent temperature derived for the two minerals already present to differ from the simple relationship for a two-phase system. In some systems oxygen isotope reversals can be developed. If cooling is not 'slow', then the mineral δ18 O values resulting from cooling will be partly dependent upon the initial temperature of the system concerned. The model successfully simulates the mineral δ18 O values that are often observed in granitic rocks. Application of the model will help in assessing the validity of oxygen isotope thermometry in different geological settings, and allows quantitative prediction of the oxygen isotope fractionations that are developed in cooling closed systems. 相似文献
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Standards for the exchange of machine-readable data are discussed at five levels covering (1) physical characteristics of the medium used in the exchange, (2) overall structure of the data file, (3) format of individual records, (4) types of information contained in a record, and (5) authority files for information definition. The standards are used by the National Geothermal information Resource for compilations of geothermal energy data.This paper was presented at the International Geological Correlation Program (IGCP) Project 98 entitled Standards for Computer Applications in Resource Studies held at Loen, Norway, September 27–October 1, 1976. 相似文献
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Frank S. Spear 《Contributions to Mineralogy and Petrology》1980,72(1):33-41
The exchange equilibrium between plagioclase and amphibole, 2 albite+tschermakite=2 anorthite+glaucophane, has been calibrated empirically using data from natural amphibolites. The partition coefficient, K
D, for the exchange reaction is (X
an/X
ab)plag ·(Na, M4/Ca, M4)amph.. Partitioning is systematic between plagioclase and amphibole in suites collected from single exposures, but the solid solutions are highly non-ideal: values of In K
D range from –3.0 at X
an=0.30 to –1.0 at X
an=0.90 in samples from a single roadcut. Changes in both K
D and the topology of the ternary reciprocal exchange diagram occur with increasing metamorphic grade. Temperature dependence of In K
D is moderate with ¯H35 to 47 kcal at X
an=0.25; pressure dependence is small with ¯V –0.24 cal/bar. Usefulness of this exchange equilibrium as a geothermometer is restricted by uncertainties in the calculation of the amphibole formula from a microprobe analysis, especially with regard to Na, M4 in amphibole, to approximately ±50 ° C. 相似文献
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The D/H ratios of separated size fractions of clay minerals in two deep sea sediments taken from depths of 30 and 1100cm in a North Pacific Ocean core were measured to investigate the extent of hydrogen isotope exchange between detrital clay minerals and sea water. The D/H ratio of each size fraction of the shallower sample was compared with that of the corresponding size fraction of the deeper sample. No differences were detected between D/H ratios of corresponding size fractions from the two levels in the core except for the <0.1μm size fraction, which makes up only 5% of the sample. Even in this size fraction only about 8–28% D/H exchange is apparent. This is interpreted as indicating that no significant hydrogen isotope exchange between clay minerals and sea water has occurred during the past 2–3 Myr. Therefore information concerning the provenance and mode of formation of detrital clay minerals can be obtained from the D/H ratios of deep sea sediments younger than 2–3 Myr. 相似文献