胶东半岛大磨曲家金矿床成矿流体物理化学条件演化   总被引：2，自引：1，他引：1  

郭春影  高帮飞  张静  王庆飞  龚庆杰  于海军 《现代地质》2008,22(5)

胶东大磨曲家金矿床流体包裹体包括水溶液包裹体、富CO2包裹体和高盐卤水包裹体3种类型,前两者发育较多,高盐卤水包裹体发育极少。流体包裹体显微测温及盐度、密度、压力估算显示,水溶液包裹体均一温度为98~376℃,据冰点温度估算,盐度为0.53%~8.28%,水溶液包裹体均一压力低于50×105Pa;富CO2包裹体完全均一温度为255~348℃,盐度为2.42%~11.43%,均一压力为1 000×105~2 500×105Pa;富CO2包裹体中CO2均一温度为23.0~32.4℃,指示该类包裹体可能含有数量不等的CH4或H2S。静水压力体制下,根据纯CO2包裹体均一压力估算成矿深度约为1 km。在270℃左右,均一压力从富CO2包裹体到水溶液包裹体急剧降低,指示成矿流体在270℃左右可能发生过一次减压沸腾过程,成矿流体盐度和密度在270℃左右也有显著的变化。因此,沸腾作用及其引起的成矿流体物理化学条件的急剧变化可能是导致大磨曲家金矿床成矿物质沉淀的重要机制。  相似文献   

福建紫金山铜金矿床成矿流体演化数值模拟——混合和沸腾过程研究   总被引：7，自引：1，他引：7  

徐文艺  任启江  徐兆文  方长泉  郭国璋  张重泽 《矿床地质》1997,16(2):163-169

利用ＣＨＩＬＬＥＲ软件模拟了紫金山铜金矿床主矿化阶段成矿流体的混合和局部减压等焓沸腾过程，模拟结果显示矿化具有低的ＨＳ＾－和Ｃａ＾２＋浓度，高的Ａｓ含量。在混全和沸腾过程中，随着温度和压力的降低，ｐＨ值和ｆＯ２逐渐降低，这是些金山铜金矿成矿流体的重要特征。  相似文献   

斑岩型钼矿床研究进展与问题   总被引：1，自引：0，他引：1  

曹冲  申萍 《地质论评》2018,64(2):477-497

本文在简要介绍全球重要成矿带斑岩型钼矿床品位、储量、时空分布以及构造背景的基础上,着重归纳了斑岩型钼矿床中Mo在岩浆—热液演化过程中的地球化学行为特征以及Mo在成矿流体中的迁移与沉淀机制两个方面的研究进展。取得了以下认识:形成斑岩型钼矿床成矿岩浆氧逸度(f_(O2))变化范围较大,但一般大于铁橄榄石—磁铁矿—石英(FMQ)缓冲体系。斑岩钼矿床形成的主要受岩浆房的大小,大体积的岩浆流体能否高效聚集到浅部岩株或岩脉,岩浆中的挥发分(例如F)含量等因素的控制,但与成矿花岗岩和出溶流体中Mo的含量高低无直接关系。成矿流体的氧逸度与p H降低对辉钼矿沉淀具有关键作用。除此之外,温度与盐度降低对辉钼矿沉淀也有重要作用。流体的多阶段沸腾可能对提高Mo品位具有重要意义。此外,应加强岩浆结晶分异过程、岩浆热液转化过程Mo的地球化学行为研究。  相似文献   

江西凤凰岽含锡黄英岩脉特征及成因   总被引：1，自引：0，他引：1  

熊小林  朱金初 《矿物岩石》1994,14(1):28-35

江西会昌县岩背火山盆地密坑山含黄玉花岗岩体的北侧外接触带，产有数条含锡黄英岩脉。据野外产状、岩石结构构造等表明岩脉属岩浆成因。稀土元素研究表明，凤凰岽黄英岩ＲＥＥ含量极低，∑ＲＥＥ及配分曲线与脉侧黄玉石英化蚀变岩有着明显的区别。富氟花岗岩浆结晶晚期衍生的富Ｓｉ，Ａｌ，Ｆ含少量Ｋ，Ｎａ的残余熔浆沿断裂上侵因压力降低产生二次沸腾，使Ｋ，Ｎａ分离进入含水相，这是富Ｓｉ，Ａｌ，Ｆ；极贫Ｋ，Ｎａ的黄英岩形成的决定因素。  相似文献   

隐伏岩体顶上带与深部成矿预测     

金旭东  张德会  万天丰 《地质通报》2010,29(2)

岩浆侵入的流体流动模拟表明.侵入体上方是流体聚焦流动的位置,流体通量远大于旁侧围岩,流体在此产生沸腾作用.随温度降低,侵入体上方渗透率逐渐增大,最大渗透率出现在侵入体的顶部.含水岩浆侵位后在其顶上带发生二次沸腾和减压过程,释放出的巨大机械能远大于围岩的抗张强度,足以引起围岩发生脆性破坏.岩浆岩顶上带的水饱和外壳及其围岩发生破裂形成陡倾裂隙和水力破裂.直立长椭球状岩浆体的侵入会在岩浆岩顶上带产生放射状和同心圆状裂隙,同时产生爆破角砾岩筒.因此侵入体顶上带的岩钟、岩枝、岩脉,放射状、同心圆状裂隙和角砾岩筒均为构造弱化带,是热液矿脉密集发育的部位.矿床地质学研究已充分证明.岩浆岩顶上带确是容纳与中酸性岩浆有关的热液矿床的最佳部位.在开展深部成矿预测和找矿的过程中,探寻隐伏岩体项上带和/或岩钟.是寻找深部与花岗岩类有关的多金属矿床的捷径.  相似文献   

Characteristics of Triassic epithermal Au mineralization at the Q prospect,Chatree mining area,Central Thailand     

Ladda Tangwattananukul  Daizo Ishiyama  Osamu Matsubaya  Toshio Mizuta  Punya Charusiri  Hinako Sato  Koichiro Sera 《Resource Geology》2014,64(2):167-181

The Chatree deposit is located in the Loei‐Phetchabun‐Nakhon Nayok volcanic belt that extends from Laos in the north through central and eastern Thailand into Cambodia. Gold‐bearing quartz veins at the Q prospect of the Chatree deposit are hosted within polymictic andesitic breccia and volcanic sedimentary breccia. The orebodies of the Chatree deposit consist of veins, veinlets and stockwork. Gold‐bearing quartz veins are composed mainly of quartz, calcite and illite with small amounts of adularia, chlorite and sulfide minerals. The gold‐bearing quartz veins were divided into five stages based on the cross‐cutting relationship and mineral assemblage. Intense gold mineralization occurred in Stages I and IV. The mineral assemblage of Stages I and IV is characterized by quartz–calcite–illite–laumontite–adularia–chlorite–sulfide minerals and electrum. Quartz textures of Stages I and IV are also characterized by microcrystalline and flamboyant textures, respectively. Coexistence of laumontite, illite and chlorite in the gold‐bearing quartz vein of Stage IV suggests that the gold‐bearing quartz veins were formed at approximately 200°C. The flamboyant and brecciated textures of the gold‐bearing quartz vein of Stage IV suggest that gold precipitated with silica minerals from a hydrothermal solution that was supersaturated by boiling. The δ¹⁸O values of quartz in Stages I to V range from +10.4 to +11.6‰ except for the δ¹⁸O value of quartz in Stage IV (+15.0‰). The increase in δ¹⁸O values of quartz at Stage IV is explained by boiling. P_H2O is estimated to be 16 bars at 200°C. The f_CO2 value is estimated to be 1 bar based on the presence of calcite in the mineral assemblage of Stage IV. The total pressure of the hydrothermal solution is approximately 20 bars at 200°C, suggesting that the gold‐bearing quartz veins of the Q prospect formed about 200 m below the paleosurface.  相似文献   

相山铀矿田邹家山矿床成矿流体特征   总被引：2，自引：0，他引：2  

郭建  李子颖  李秀珍  聂江涛  王健 《铀矿地质》2014,(5):263-270

通过流体包裹体的岩相学研究、显微测温和激光拉曼探针测试,探讨了邹家山铀矿床成矿流体特征、演化及矿质沉淀方式。研究结果表明,该矿床的成矿流体为中低温热液,碳氢化合物对铀的富集具有不可忽视的作用,流体持续的沸腾作用是矿质沉淀的主要因素。  相似文献   

The Influence of Pan Evaporation Conditions on Na Cl crystallization     

TANG N  ZHANG Shuang  HE Guohu  ZHANG Lei  CHENG Penggao 《《地质学报》英文版》2014,88(Z1):375-376

正1 Introduction Crystallization is one of important unit operations in the chemical production process,which requires not only the crystal product with high purity and yield,but also the available particle size of the crystal products to ensure product quality.Crystallization process is affected by  相似文献   

浙江中生代浅成热液金银成矿作用的耗散结构模型     

胡永和  王建国  朱兴盛 《浙江国土资源》2001,17(2):17-26

浙江中生代主要浅成热液金银矿床在蚀变-矿化过程中的一些物理化学特征参数(如T、P、St和ρ等)呈非线性的变化关系,其控制变量是P、T和PH值.推断条带(或环带)状构造的矿脉(石)是由减压沸腾作用造成的.据Drummond等(1985)沸腾的模拟计算和研究表明,[H+]浓度是决定沸腾热液中的Au、Ag等成矿元素命运的主要因素.因此,可以[H+]浓度(状态变量)作为序参量来反映成矿溶液中Au、Ag浓度的变化趋势;并建立其自组织过程的动力学方程与开放沸腾热液系统Au、Ag沉淀的耗散结构模型.  相似文献   

Geysers of Enceladus: Quantitative analysis of qualitative models     

Nikolai V. Brilliantov  Jürgen Schmidt 《Planetary and Space Science》2008,56(12):1596-1606

Aspects of two qualitative models of Enceladus’ dust plume—the so-called “Cold Faithful” [Porco, C.C., et al., 2006. Cassini observes the active south pole of Enceladus. Science 311, 1393-1401; Ingersoll, A.P., et al., 2006. Models of the Enceladus plumes. In: Bulletin of the American Astronomical Society, vol. 38, p. 508] and “Frigid Faithful” [Kieffer, S.W., et al., 2006. A clathrate reservoir hypothesis for Enceladus’ south polar plume. Science 314, 1764; Gioia, G., et al., 2007. Unified model of tectonics and heat transport in a Frigid Enceladus. Proc. Natl. Acad. Sci. 104, 13578-13591] models—are analyzed quantitatively. The former model assumes an explosive boiling of subsurface liquid water, when pressure exerted by the ice crust is suddenly released due to an opening crack. In the latter model the existence of a deep shell of clathrates below Enceladus’ south pole is conjectured; clathrates can decompose explosively when exposed to vacuum through a fracture in the outer icy shell. For the Cold Faithful model we estimate the maximal velocity of ice grains, originating from water splashing in explosive boiling. We find that for water near the triple point this velocity is far too small to explain the observed plume properties. For the Frigid Faithful model we consider the problem of momentum transfer from gas to ice particles. It arises since any change in the direction of the gas flow in the cracks of the shell requires re-acceleration of the entrained grains. While this effect may explain the observed speed difference of gas and grains if the gas evaporates from triple point temperature (273.15 K) [Schmidt, J., et al., 2008. Formation of Enceladus dust plume. Nature 451, 685], the low temperatures of the Frigid Faithful model imply a too dilute vapor to support the observed high particle fluxes in Enceladus’ plume.  相似文献