四川盐源西范坪斑岩铜矿的钾长环斑结构及其意义

四川盐源西范坪斑岩铜矿床中存在大量钾长环斑结构。研究表明这一结构是由正在冷凝的岩浆分泌出的成矿流体与刚结晶的斜长石相互作用形成的。在流体 -矿物相互作用过程中 ,流体从已经结晶的矿物尤其是黑云母中萃取出大量铜等成矿物质 ,从而进一步提高了体系的成矿能力。钾长环斑结构的出现不仅为矿床的岩浆热液成因提供了佐证 ,而且是一种良好的找矿标志。     

华南地洼阶段低温地球化学作用与硅化岩-交代石英岩

本文以较全面的资料数据,论述了两种不同类型硅化岩-交代石英岩的地球化学特征、交代机制、成因及与矿的关系。     

Textural and chemical zoning in garnets related to mantle metasomatism and deformation processes

A few texturally-zoned garnets were found in a polymict peridotite (JJG1414) from the Cretaceous kimberlite, Kimberley, South Africa. The systematic analyses of electron and ion microprobe as well as laser fluorination technique reveal the existencal of marked elemental and oxygen isotopic zonation in these garnets, corresponding to the textural zonation. The rims are normally enriched in Ca, Ti, Cr, LREE, Sr, Nb, and depleted in Mg, Al and¹⁸O. It is demonstrated that these garnets were infiltrated by melts/fluids, probably representing the disequilibrated products of fluid-assisted mantle deformation.     

西秦岭李坝金矿蚀变岩的地质地球化学特征

李坝浊积岩型金矿床赋存于西秦岭北带中泥盆统李坝群浊积岩建造中 ,赋矿围岩蚀变主要为黑云母化、绿泥石化、绢云母化、硅化和碳酸盐化 ,且蚀变分带明显。通过对该矿床各种蚀变岩的常量元素、微量元素及稀土元素的地球化学特征研究 ,探讨了元素在碱交代 K交代及酸交代过程中的地球化学行为。结果表明 ,Si O2 含量 ,Fe2 O3 含量 ,L REE/ HREE,Σ L REE,(L a/ L u) cn,(L a/ Sm) cn,(Tb/ Yb) cn及微量元素的含量等随着 K交代作用强度的增强 ,显示出规律性的变化。最后讨论了 K交代作用及酸交代作用与金矿化之间的关系。     

碳酸盐岩风化成土的交代作用机理：I．矿物与微结构证据

通过对贵州、广西亚热带岩溶地区碳酸盐岩红色风化壳典型剖面的矿物学与微结构研究，从不同研究尺度和剖面不同部位都观察到大量碳酸盐 风化成土过程中交代作用发育的最直接和最重要的矿物与微结构证据。首次较为系统讨论了碳酸盐岩风化成土的交代作用机理，提出了碳酸盐岩风化成土过程中的矿物交代演化序列。     

江西省乐安县相山矿田荷上铀矿床蚀变特征及其意义

荷上铀矿床赋存于花岗斑岩体的内外接触带,围岩为火山熔岩及陆相碎屑沉积岩、基底变质岩。矿体受裂隙密集带控制,空间上与花岗斑岩密切相关。详细研究了荷上铀矿床的围岩蚀变特征,并将该矿的蚀变和成矿过程划分为三个阶段,即铀-赤铁矿成矿阶段,铀-萤石化-绿泥石-水云母化阶段和铀-碳酸盐成矿阶段,其中第二阶段为主要成矿阶段。提出岩石的褪色蚀变(以浅色矿物蚀变为主,另见绿泥石化、黄铁矿化等)对成矿有间接指示意义,而长石变红、石英变黑、粉末状紫色萤石化、磷灰石化等蚀变则对铀成矿有直接指示意义。在分析荷上铀矿床蚀变特征的基础上,提出该区下一步工作建议。     

Zircon SHRIMP U-Pb age of garnet olivine pyroxenite at Hujialin in the Sulu terrane and its geological significance

Abundantbasic-ultrabasicbodiescropoutintheDabie-Suluultrahighpressure(UHP)metamorphicbeltandoccurasgroupandband.Muchresearchworkhasbeencarriedoutonthebasic-ultrabasicbodiesandmadeagreatprogressespeciallyonmineralogy.ThediscoveryofmineralassemblagesofUHPmetamorphismandexsolvedlamellaesuggestthattherocksmaycomefromthedeepmantleorwasonceemplacedintotheshallowlevelofthecrustandthensubductedtothemantledepthsduringsub-ductionofthecrust[1—13].However,theiroriginandtec-tonicsettingarestillacontrov…     

Carboniferous adakites and Nb-enriched arc basaltic rocks association in the Alataw Mountains, north Xinjiang： interactions between slab melt and mantle peridotite and implications for crustal growth

Adakites and Nb-enriched arc basaltic rocks (NEABs) in arc setting, which are closely correlated in petrogenesis, have recently been widely followed with interest[1—9]. In general, adakite is derived from partial melting of subducting oceanic crust[1]. When adakitic magma (slab melt) passes through the mantle wedge, the interactions between slab melt and mantle peridotite will occur: slab melt is contaminated by peridotite, meanwhile peridotite is metasomated by slab melt. The NEABs are d…