中国东部岩石圈铅同位素化学结构与动力学研究

通过对中国东部不同地质构造单元内300余个中生代花岗岩类侵入体和14个中、新生代玄武岩和蛇绿岩岩石分析研究,获得了1455个长石铅、68个全岩铅和9个玄武岩铅同位素新资料。所获得的最终主要成果和新认识、新概念归纳如下: 1.定量地将中国东部岩石圈地壳和地幔分成三大块体,即华北、华南、东北。它们之间的界线在东经116°、北纬30°和42°附近(图1)。 2.综合Pb、Sr、O、Nd多元同位素示踪组合模式,将华北岩石圈陆壳板块划分出五个构造同位素地球化学省,亦即是五个构造花岗岩省和五个构造成矿省:冀北—辽北省(A1-1)、阴山—五台—燕山省(A1-2)、晋中—冀南—鲁西—辽南省(A2)、大别—胶南省(A3-1)和秦岭—北淮阳—肢东省(A3-2);华南岩石圈陆壳板块划分出八个构造同位素地球化学(构造花岗岩或构造成矿)省:洪泽湖—太湖省(B1),西南扬子省(B2-1)、北扬子省(B2-1)、南扬子省(B2-3)、南岭省(B3-1)、三江省(B3-2)、武夷省(B4-1)和闽台省(B4-2);东北岩石圈陆壳板块暂划分出两     

甘肃西成矿田铅锌矿床的成矿物质来源探讨

本文系统地研究了甘肃省西成矿田铅锌矿床的地层地球化学和铅同位素地球化学特征,得出了该区成矿金属物质主要取自基底地层而不是含矿层的新认识。     

吉林海沟金矿床自然金的矿物学特征

海沟金矿床是一个大型的沉积变质—热液矿床。自然金是矿床主要的金矿物,它主要富集于自然金—硫化物阶段。自然金的晶形多呈各种形态的显微金分布于硫化物、碲化物及石英的粒间或裂隙中。它的比重大,其晶胞参数与纯金接近。金的成色高并且变化小,成色的高低与矿物组合有关,但矿化深度和温度对它的影响不大。金的颜色指数随成色的变化而变化。自然金的矿物学特征与矿床成因类型有密切关系。     

Phase Relations in the System Pb—Sn—Fe—Sb—S

Phase relations in the system Pb-Sn-Fe-Sb-S were investigated through the diagrams of projecting plane 8x(PbS-SnS-SnS2)from the vertrex point Fe0.96Sb2.04S4.12by vacuum silica tube technique.Experimental results have shown that franckeite has a wide solid solution with substitution of Pb^2 by Sn^2 ,In franckeite s.s.the content of Sn^2 varies from 0 to 4.8 atoms (total metal atoms are 11 atoms per formula) at 500℃ and 0-4.0 atoms at 400℃,respectively,Meanwhile,the content of Sn^4 ranges from 1.3to 2.0 atoms at 500℃ and 1.5-2.1 atoms at 400℃ in franckeite s.s.These results are consistent well with analytic data on natural franckeite.The cylindrite solid solutiopn has a relatively small range with Sn^2 -1.8atoms and Sm^4 =3.2-4.2 atoms per formula at 500℃ and ,Sn^2 =0.5-1.7 atoms and Sm^4 =3.3-4.2 atoms at 400℃ which are comparable with natural cylindrite.The phases coexisting in equilibrium with franckeite s.s. are galena,boulangerite,robinsonite.teallite,SnS,cylindrite.s.s.and synthetic phase Ⅲ ss or I ss.The cylindrite s.s.coexists with SnS2 and the above mentioned phases,but not with galena.teallite and SnS,and probably not with boulangerite in this projecting plane.     

浙东南金银铅锌区域成矿作用的若干问题探讨

浙东南(绍兴-江山断裂带以东)地区,在燕山晚期存在着统一的区域性金银和铅锌成矿作用.它们皆属浅成中-低温热液矿床.隆起带和坳陷带中的矿床具有不同的形成机制.金银矿床规模与脉石英包裹体中气相CH_4/H_2O和CO_2/H_2O比值正相关.     

137Cs及210Pbex方法湖泊沉积计年研究新进展

The ¹³⁷Cs and ²¹⁰Pb_ex techniques are widely employed for dating recent sediments of lakes. There is important provision to gain dating results correctly with the sampling device of no-disturbing sediments and the sample separation of high precision. The secondary peak of ¹³⁷Cs in sediment horizon of 1975 could be as an assistant dating time marker. Most part of ¹³⁷Cs in sediments is at stable position which provides reliability for ¹³⁷Cs dating time marker. The post-depositional remobilization of ²¹⁰Pb could lead to the lower rate of sediment accumulation in seasonal anoxic hypolimnia of lakes.The transformation of Pb species has provided the geochemical condition of its diffusion in the processes of early diagenesis. The diffusion mechanism of Pb-Po is controlled by cycling Fe-Mn, respectively.     

我国地理学发展的回顾与展望--地理学:方向正在变化的科学

我国地理学自新中国成立以来取得了辉煌的成就，在跨入21世纪之时面临着一系列挑战和重大任务。我国经济和社会的迅速发展，强烈地改变了我国自然结构和社会经济结构，我国及各地区的“人－地”关系协调和可持续发展是我们面临的重大任务，地理学是实现这些国家重大任务的重要支撑科学之一，肩负着责无旁贷的重任，有着广阔的发展空间。