湘黔边境铅锌矿带硫铅同位素组成特征

本文从地球化学硫、铅同位素组成角度出发,对湘黔边境铅锌矿带的成矿时代、成矿温度、物质来源及矿床成因进行探讨。该矿带铅锌矿床属沉积—改造型矿床,成矿金属物质来源于地幔,矿质硫来源于矿层上覆中上寒武统海相蒸发白云岩中的膏盐;成矿温度为中—低温(135—200℃);成矿时代主要是加里东期,加里东早期形成矿源层,晚期溶解、活化、混合、改造矿源层形成矿床。该矿带属加拿大派纳派因特式铅锌矿,是寻找以锌为主的铅锌矿很有前景的地区。     

普通铅同位素演化系统模式

已有的几种普通铅同位素模式仅反映了一些封闭体系铅同位素混合的特殊情况,不便于有效地应用于地质历史时期复杂的地质作用过程。本文应用概率论方法,从理论上分析包括开放体系在内的13种不同系统普通铅同位素混合的23种情况,讨论各种情况下铅同位素资料的地质年代学意义与地质事件发生年代的计算方法,从而建立多阶段铅同位素演化的系统模式。应用读系统模式研究燕山地区的成岩成矿时代,所得结果与其它方法测出的年龄一致。     

秦岭勉略带中鞍子山蛇绿杂岩的地球化学：——古洋壳碎片的证据及意义

鞍子山蛇绿杂岩位于秦岭勉略带东段,它由蛇纹石化变质橄榄岩和ＭＯＲＢ型变质镁铁质岩组成。蛇纹石化变质橄榄岩主要是方辉橄榄岩和少量二辉橄榄岩,表了古洋幔的上部岩石;变质镁铁质岩为斜长角闪岩,其原岩是基性火成岩类,它多以亏损ＬＲＥＥ元素和具有很高的＾１４３Ｎｄ／＾１４４Ｎｄ值为特征,类似于现代洋壳中的洋中脊玄武岩（ＭＯＲＢ）,代表了古洋壳的残余部分。这表明鞍子山晕绿杂岩是勉略混杂岩带中又一个典型的蛇绿岩     

Metallogenic Mechanism of the Tianbaoshan Pb—Zn Deposit,Sichuan

The Tianbaoshan Pb-Zn deposit in Sichuan Province,exhibiting open-space-filling and /or replacement textures,occurs as being of vine style in the Sinian(Late Proterozoic) carbonate rocks,and is simple in ore composition.A systematic study of lead isotope and rareearth elements reveals that the ore-forming materials were derived from multiple sources.The ultimate source of the sulfur in all stages in seawater sulfate but the reducing mechanisms are different,The carbon was derved from marine carbonate and organic matter,The ore-forming fluid,meteoric in origin,belongs to a Ca^2 -Mg^2 -Cl^--Hco3^- type of weak acidic to alkalic solutions with a salinity of about 5wt% NaCl.The ore was formed at the depth of about 1 km from 150 to 250℃ during the main stage of ore deposition.The heated meteoric water,after extracting ore materials from wall rocks,evolved into ore-forming solution with a low salinity, in which metals were trasported as chloride complexes such as PbCl,ZnCl and ZnCl.The metal-bearing solution moved upward along deep faults to low-pressure zones,where the metal ions reacted with reduced sulfur and were precipitated as sulfied minerals.The textures of the minerals were controlled by the rate at which the reduced sulfur was supplied.     

天然沸石对Pb(Ⅱ)和Ni(Ⅱ)离子的吸附作用研究

在静态条件下,研究了沸石对重金属离子（如Ｐｂ＾２＋和Ｎｉ＾２＋）的吸附与交换。结果表明,沸石对重金属离子具有较强的吸附性能,ｐＨ值的影响吸附的主要因素,离子交换和表面络合反应是主要吸附形式。     

满洲里—西旗斑岩铜多金属成矿系列REE地球化学特征及应用

对该区燕山期斑岩铜多金属成矿系列进行了REE地球化学研究,并结合岩石化学、包体、微量元素、氢氧同位素综合分析。各(蚀变)岩体REE分布模式可分为三种类型。在乌山矿床Q-Kf、Q-Ser、I-H三个蚀变带中REE分别呈氯化物、F~-络合物、F~-、CO_3~(2-)络合物形式。蚀变是两期叠加的,REE的淋滤、沉淀伴随成矿元素的再活化、再富集。首次发现铕亏损对矿化具有指示意义,蚀变岩δEu愈小,矿化愈好。提出了斑岩体含矿性的五条判别标志,据此对外围岩体含矿性进行了判别排队。     

卵石地层的特殊性及其对基坑支护的影响分析

主要从卵石地层的特征分类、特殊结构及场内施工条件3个方面,对基坑支护结构选型及施工工艺选择进行深入、系统的分析论证,力求使在卵石地层中的基坑支护设计方案更科学、经济,使施工方法、工艺更具可操作性。     

柴达木盆地北缘中、新生代构造演化探讨

本文通过近年来的地震反射信息研究,对柴达木盆地北缘中、新生代地质构造演化进行了分析,透过红山地区这个窗口,揭示柴达木盆地内中、新生代两个世代的构造成因类型,展示二者叠置关系和构造样式,认为该区存在先张后压的演化历史,且后期挤压作用破坏和改造早期拉张构造样式,从而更有效地指导盆地中生代油气藏的勘探。     

The Coupled Re—Os and Pt—Os Systematics：A Theoretical Consideration

The ^190Pt-^186Os system should be a unique tracer for mantle processes be-cause both Pt and Os are concentrated in the mantle.The ^190Pt-^186Os system will also be a good supplement to the ^187Re-^187Os system for dating and tracing mantle pro-cesses because the ^190Pt-^186Os system is not so easily contaminated by crustal materials as the ^187Re-^187Os system.In turn,the application of the ^187Re-^187Os system to Pt-enriched materials uncontaminated by crustal materials will indirectly refine the half life of ^190Pt.The ^190Pt is refined.In the coupled ^187Re-^187Os and ^190Pt-^186Os sys-tematics,an ^186Os*/^190Pt-^187Os*/^187Re Concordia diagram similar to the ^206Pb*/^238U-^208Pb*/^232Th Concordia can be constructed.In such a Concordia diagram,a date will be obtained so long as the ^190Pt-^186Os system remains closed even if the ^187Re-^187Os sys -tem is contaminated by crustal materials.In addition ,for the coupled ^190Pt-^186Os and ^187Re-^187Os systematics,the mantle processes and the interactions between the mantle and the crust will be described by two ratios:^186Os/^188Os and ^187Os/^188Os .The coupled ^187Re-^187Os and ^190Pt-^186Os systematics will be a powerful tool in the investigation of the geodynamic history of the Earth because the ^187Re-^187Os system is sensitive to the interactions between the mantle and the crust,while the ^190Pt-^186Os system is a good tracer for mantle processes.