中酸性岩浆体系成矿流体及微量元素地球化学特征   总被引：5，自引：0，他引：5       下载免费PDF全文

李剑  吕志成董方浏 《中国地质》2005,32(4):614-624

从流体成矿作用角度出发，与酸性岩浆体系有关的成矿流体可以分为：酸性岩浆硅酸盐熔融体，岩浆一热液过渡阶段硅酸盐熔融体及其分异的流体，酸性岩浆熔体分异形成的热水成矿溶液。酸性岩浆体系主要提供热源和部分矿质，其提供的热源驱动地下水淋滤、萃取围岩中的成矿物质形成地下水热液成矿流体。变质岩混合岩化形成花岗质岩浆过程中所形成的混合岩化成矿流体。在此基础上，讨论了上述不同成矿流体的微量元素地球化学特征及其对成矿的控制作用。  相似文献   

云南马厂箐（铜、钼）金矿床地质特征及成因研究   总被引：18，自引：5，他引：18  

葛良胜  张晓辉等 《地质与勘探》2002,38(5):11-17

云南马厂箐（铜、钼）金矿床是滇西北地区与喜马拉雅期富碱侵入岩类有关矿床的典型代表之一。矿体（脉）的产出与区内富碱岩体（脉）具有空间上形影相随、时间上相近或稍晚、成因上密切相关的联系，蚀变分带明显，对矿床和相关的富碱岩体（脉）开展的金丰度值、同位素和稀土元素研究表明，富碱岩体本身并不是矿质的源地。成矿流体和主要矿质均源于地球深部，以上地慢或壳慢混合带为主。章进一步讨论了岩浆成岩与流体成矿之间的关系，反映了与富碱岩浆活动有关金矿床在成因上具有复杂性。  相似文献   

老柞山金矿田鸡爪沟金矿床地质特征及成因探讨   总被引：1，自引：1，他引：1  

何宝林  赵海鹏 《矿产与地质》2002,16(3):165-167

分析了鸡爪沟金矿床地质特征和成因 ,并对形成过程进行理论推导 ,认为该矿床为与火山作用有关的中温岩浆热液充填型矿床。  相似文献   

广西凭祥地区早二叠世的岩浆弧及其构造意义   总被引：7，自引：0，他引：7  

吴根耀  季建清  何顺东  钟大赉 《矿物岩石》2002,22(3):61-65

广西凭祥地区有3种不同建造背景的二叠-三叠系，深水相的下二叠统呈一飞来峰推覆在台地型的石炭纪-早三叠世沉积和早-中三叠世浊积岩上，与前者共生的基性-超基性岩是古特提斯岩浆弧的记录，当时的被动大陆边缘在百色阳圩-田林八渡，说明洋壳向南西消减，早二叠世弧的原形成位置可能在越南境内，早-中三叠世的弧则已向北东迁移，在中越交界区形成图尔基式造山带。  相似文献   

REE Geochemistry of the Lead—Zinc Ores from the Jinding Lead—Zinc Deposit,Lanping,Yunnan   总被引：3，自引：1，他引：3  

牟传龙  余谦  张立生 《中国地球化学学报》2002,21(1):57-64

Nineteen volcanic and magmatic rock samples were collectecd from the Jinding leadzinc deposit and its surrounding areas in Yunnan.The ICP and AES analyses,feferred to the previous results,show that the metal minerals and altered rocks in the Jinding lead-zinc deposit display a decreasing trend of ∑REE from the early to late stages of mineralization,and similarities in REE distribution patterns,indicating that the ore fluids are characterized by high LREE enrichment,markedly negative δCe anomaly and slight δEu anomaly.These REE distribution paterns exhibit striking similarities to those of the Pliocene trachyte in the study area,both of which are similar in ∑REE,LREE/HREE ratio,δEu and δCe.The ore fluids besides the basin fluids in the deposit are also closely related to those associated with Pliocene trachyte magmas.  相似文献   

从流体包裹体研究探讨金属矿床成矿条件   总被引：29，自引：4，他引：29  

芮宗瑶  李荫清  王龙生  王义天 《矿床地质》2003,22(1):13-23

根据作者多年来对流体包裹体的研究成果，参考了国内外的研究结论，提出了一个新的成矿流体分类方案，并评述了我国若干典型金属矿床的研究状况，由此探讨了金属矿床的形成机制。  相似文献   

辽宁庄河鞍子山超单元岩浆侵位变形构造     

王启伟 《地质通报》2003,22(2):118-123

鞍子山超单元由4个单元组成，各单元不同程度地发育岩浆侵位变形构造。侵位变形构造主要由叶理构造组成，闪长质包体，钾长石斑晶总体按优选方位定向，三者产状一致，平行接触带分布。从早期单元至晚期单元，随着岩浆侵位叶理构造变形强度减弱，闪长质包体数量减少，压扁变形程度降低，钾长石斑晶从明显按优选方位定向到杂乱分布。根据上述特征，将该超单元浆侵位变形、中等侵位变形、弱侵位变形及基本无侵位变形4个带。  相似文献   

Contrast in Fluid M etallogeny between the Tianmashan Au-S Deposit and the Datuanshan Cu Deposit in Tongling, Anhui Province     

LEE Hyun Koo 《《地质学报》英文版》2003,77(1):116-124

A comprehensive contrast of ore-forming geological background and ore-forming fluid features, especially fluid ore-forming processes, has been performed between the Tianmashan and the Datuanshan ore deposits in Tongling, Anhui Province. The major reasons for the formation of the stratabound skarn Au-S ore deposit in Tianmashan and the stratabound skarn Cu ore deposit in Datuanshan are analyzed in accordance with this contrast. The magmatic pluton in Tianmashan is rich in Au and poor in Cu, but that in Datuanshan is rich in Cu and Au. The wallrock strata in Tianmashan contain Au-bearing pyrite layers with some organic substance but those in Datuanshan contain no such layers. Moreover, the ore-forming fluids in Tianmashan are dominantly magmatic ones at the oxide and sulfide stages, but those with high content of Cu in Datuanshan are mainly groundwater fluids. In addition, differences in compositional evolution and physicochemical condition variation of the ore-forming fluids result in gradual dispersion  相似文献   

辽宁地区的幔枝构造          下载免费PDF全文

白永俊  夏洪宝  赵艳秋 《地质找矿论丛》2003,18(Z1):1-6

将辽宁地区划分为4个幔枝构造:山海关幔枝、辽东南幔枝、建平-阜新幔枝、西丰幔枝,文章分述了它们各自组成与构造特点,并举例说明了辽宁幔枝构造通过其三个次级构造单元对成矿的控制规律.  相似文献   

Temporal variations in magma composition at Merapi Volcano (Central Java, Indonesia): magmatic cycles during the past 2000 years of explosive activity   总被引：1，自引：0，他引：1  

Ralf Gertisser  Jrg Keller 《Journal of Volcanology and Geothermal Research》2003,123(1-2):1

Merapi Volcano (Central Java, Indonesia) has been frequently active during Middle to Late Holocene time producing basalts and basaltic andesites of medium-K composition in earlier stages of activity and high-K magmas from 1900 ¹⁴C yr BP to the present. Radiocarbon dating of pyroclastic deposits indicates an almost continuous activity with periods of high eruption rates alternating with shorter time spans of distinctly reduced eruptive frequency since the first appearance of high-K volcanic rocks. Geochemical data of 28 well-dated, prehistoric pyroclastic flows of the Merapi high-K series indicate systematic cyclic variations. These medium-term compositional variations result from a complex interplay of several magmatic processes, which ultimately control the periodicity and frequency of eruptions at Merapi. Low eruption rates and the absence of new influxes of primitive magma from depth allow the generation of basaltic andesite magma (56–57 wt% SiO₂) in a small-volume magma reservoir through fractional crystallisation from parental mafic magma (52–53 wt% SiO₂) in periods of low eruptive frequency. Magmas of intermediate composition erupted during these stages provide evidence for periodic withdrawal of magma from a steadily fractionating magma chamber. Subsequent periods are characterised by high eruption rates that coincide with shifts of whole-rock compositions from basaltic andesite to basalt. This compositional variation is interpreted to originate from influxes of primitive magma into a continuously active magma chamber, triggering the eruption of evolved magma after periods of low eruptive frequency. Batches of primitive magma eventually mix with residual magma in the magmatic reservoir to decrease whole-rock SiO₂ contents. Supply of primitive magma at Merapi appears to be sufficiently frequent that andesites or more differentiated rock types were not generated during the past 2000 years of activity. Cyclic variations also occurred during the recent eruptive period since AD 1883. The most recent eruptive episode of Merapi is characterised by essentially uniform magma compositions that may imply the existence of a continuously active magma reservoir, maintained in a quasi-steady state by magma recharge. The whole-rock compositions at the upper limit of the total SiO₂ range of the Merapi suite could also indicate the beginning of another period of high eruption rates and shifts towards more mafic compositions.  相似文献