综合物探测量在桃山地区铀矿勘查中的应用

为了深度挖掘桃山铀矿田的资源潜力,在桃山地区开展了综合物探测量,结果表明,CSAMT测量能反映出断裂及裂隙密集带的特征,特别是断裂的影响宽度、深度、两盘结构变化等;磁法测量能圈定与铀成矿有紧密关系的黑云母二长花岗岩的分布范围。根据区内已知铀矿床的的分布,分析了铀矿床的地球物理特征,总结了地质—地球物理找矿模式,预测了铀找矿有利地段,取得了好的勘查成果。     

粤西长坑金矿同位素地球化学特征及成因研究

长坑金矿主要产在长坑下石炭统灰岩与上三叠统页岩断层不整合面下的硅质岩中，矿化可分为两期，早期金矿化为层状及透镜状，和硅质岩的产状一致，其δ34S‰。在─35．4～—0．3之间，极差大，变化大，具沉积硫的一般特征；成矿流体的δD‰为─80～—59。晚期矿化主要以辉锑矿-石英脉形式产出，其δ34S‰：0．8～2．3，均一，变化小，和早期矿化有明显差异，晚期矿化成矿流体的δD‰：─30～—46。两期矿化铅同位素组成相似，和下伏地层的基本一致。据矿床的地质地球化学特征及前人有关硅质岩成因认识，认为长坑金矿早期矿化主要是热水沉积形成的，晚期矿化是改造形成的，成矿物质主要来自下伏地层。     

Recycled crust controls contrasting source compositions of Mesozoic and Cenozoic basalts in the North China Craton

We explore Fe/Mn and Nb/Ta ratios of basalts as potential tracers for differentiating melts of recycled mafic crustal lithologies from peridotitic melts. Trace elements and Fe/Mn ratios of the Mesozoic and Cenozoic basalts from East China were analyzed by ICP-MS. Low Nb/Ta ratios (15.4 ± 0.3 (2σ, n = 45)), high Nb and Ta contents (60.1 and 4.01 ppm) and high Fe/Mn ratios (64.7 ± 1.5 (2σ, n = 45)) characterize the <110 Ma basalts. Mesozoic basalts with ages >110 Ma are characterized by superchondritic Nb/Ta ratios (20.1 ± 0.3 (2σ, n = 25)), low Nb and Ta contents (10.8 and 0.54 ppm) and slightly lower Fe/Mn ratios (60.0 ± 1.1 (2σ, n = 25)). Both the Mesozoic and Cenozoic basalts have Fe/Mn ratios higher than basaltic melt formed by partial melting of peridotite at the same MgO and CaO levels. Although both the Mesozoic and Cenozoic basalts are characterized by highly fractionated REE patterns, the >110 Ma basalts have island arc-type trace element patterns (i.e., depletion in Nb and Ta), whereas OIB-type trace element patterns (e.g., no depletion in Nb and Ta) are characteristic of the <110 Ma basalts. Based on D_Fe/Mn values for olivine, clinopyroxene, orthopyroxene and garnet, high Fe/Mn ratios and negative correlations of Fe/Mn with Yb (Y) of the <110 Ma basalts suggest clinopyroxene/garnet-rich mantle sources. The lower Fe/Mn ratios and positive correlations of Fe/Mn with Y and Yb in the >110 Ma basalts suggest orthopyroxene/garnet-rich mantle sources. Combining these data with Sr-Nd isotopes, we present a conceptual model to explain the Nb/Ta ratios and PM-normalized trace element patterns of the >110 and <110 Ma basalts. Preferential melting of recycled ancient lower continental crust during Mesozoic lithospheric thinning resulted in (1) peridotite-melt/fluid reaction that formed the orthopyroxene/garnet-rich mantle sources for the >110 Ma basalts, and (2) peridotite + rutile-bearing eclogite mixing that formed the clinopyroxene/garnet-rich mantle sources for the <110 Ma basalts. The choice of models may indeed be arbitrary and non-unique, but the goal is to seek relatively simple forward models that explain the characteristics of the lavas, and the differences between the >110 and <110 Ma basalts, in a relatively consistent geodynamic framework.     

北京西山髫髻山组火山岩Sm—Nd等时线年龄初步研究

根据 6个火山岩样品的分析结果 ,得到北京西山髫髻山组的年龄为 188±19Ma。结合古生物资料分析 ,这个年龄结果表明西山地区髫髻山组的年代可能不晚于中侏罗世 Bajocian阶。因此 ,北京西山地区下侏罗统发育的褶皱构造可能代表了早侏罗世时期的燕山运动造山事件     

锰的氧化物和氢氧化物在污染水体净化中的应用研究现状

经过对锰的氧化物和氢氧化物在净化污染水体中的应用综合研究，发现该氧化物和氢氧化物样品能有效去除污染水体中的有毒有害金属离子和 氧化降解苯酚、2－丙醇、苯及印染废水等有机物，其污染净化能力主要是基于表面络合反应、表面离子交换作用和变价元素的氧化还原作用。同时介绍了锰氧化物和氢氧化物所具有的4个环境属性；离子交换、氧化还原、粒径效应和孔道效应，提出将结构特征与环境化学有机结合，深入探讨其环境属性与污染净化能力之间的关系是目前主要的研究方向。     

大别造山带现今地壳结构-岩石组成研究

通过大别造山带岩石地震波速的高温高压实验测定值与地震测深断面观察值的对比，结合地表出露岩石对深部岩石组成的地球化学示踪，揭示了该造山带现今地壳各结构层的基本岩石组成：上地壳主要由长英质岩石组成，榴辉岩在其中仅占0～20％；中地壳(低速层)主体由长英质片麻岩和花岗岩组成；下地壳上部由80％镁铁质麻粒岩和20％长英质麻粒岩组成；下地壳下部由幔源底侵岩浆作用形成的镁铁质麻粒岩组成。下地壳和上地幔的泊松比为0.265～0．280，明显高于榴辉岩的泊松比，表明其中即使有榴辉岩存在，含量也应极少。各构造单元出露的白垩纪花岗岩具有相似的化学组成，其铅、钕与锶同位素组成均可与北大别的核杂岩相对比，表明花岗岩浆均应以深部核杂岩为源岩。因此，被白垩纪花岗岩侵入的南大别超高压变质岩单元和宿松高压变质岩单元深部均应由核杂岩组成，亦即超高压和高压变质岩应呈拆离的构造岩片覆盖于核杂岩之上。鉴于白垩纪花岗岩的钕模式年龄(tDM)均集中于古元古代(1．8～2．2Ga)，表明花岗岩的源区应限于核杂岩中构成原中地壳下部的古元古代结晶基底岩层。这为中地壳主要由长英质片麻岩组成提供了佐证。考虑到大量花岗岩浆的抽出，应留下更大体积的镁铁质岩残留体，后者在地壳流变增厚调整过程中可能因密度增大而下沉，也可能因地震波速增大而显示下地壳的特征，更可能由于这两方面的原因而使由镁铁质残留体组成的原中地壳下部转变成现今下地壳上部的组成。根据大别碰撞后基性火山岩和侵入岩的地球化学研究，还可证明组成大别下地壳的镁铁质岩更可能是1.1Ga前而非中生代形成的底侵岩层。实践表明，上述两方面研究的结合可较好揭示区域地壳结构一组成。     

辽西凌源地区义县组火山岩锆石U-Pb年代学 和地球化学特征

对辽西凌源地区义县组的1件流纹岩样品进行锆石U-Pb年代学研究,获得的年龄为(124.4 1.4)Ma,与前人对辽西北票、义县、凌源等地区通过K-Ar、Ar-Ar、U-Pb等定年方法获得的义县组年龄基本一致,时代为早白垩世.7件典型火山岩样品的地球化学研究结果表明,该火山岩的SiO2=65.6%～73.4%,MgO=0.35%～1.23%,Mg#=16～41,Al2O3=13.40%～16.79%,Na2O=3.54%4.26%.Sr=(445～774)×10-6,Yb=(0.51～0.97)×10-6,,Y=(7-14)×10-6,Sr/Y=49～66,LaN/YbN=33～48,高Sr和Sr/Y比值,低Y和Yb,轻重稀土元素分异明显,显示出埃达克岩的地球化学特征,但其Mg#较低.它们可能是加厚的基性下地壳部分熔融的产物.     

湖南锡矿山超大型锑矿床H、O、Si同位素地球化学特征

本文对湖南锡矿山超大型锑矿床H、O、Si同位素地球化学特征的研究表明，成矿过程中成矿热液与围岩发生了大规模O同位素交换作用，可见明显“18O漂移”现象，其中硅质可能来自深部地层，锑矿床系古水热系统活动产物。     

An Infrared Photometric Study of Galaxies with Extragalactic H2O Maser Sources

All galaxies with extragalactic H_2O maser sources observed so far are collected. With the 2MASS and the IRAS photometric data an infrared study is performed on those galaxies.By a comparison between the H_2O maser detected sources and non-detected sources in the infrared it is indicated that infrared properties in the IRAS 12-25μm and 60-100μm are important for producing H_2O masers in galaxies.It is also found that the H_2O maser galaxies with different nuclear activity types have rather different infrared properties mainly in the IRAS 12-60μm region.     

Identification and evaluation of desertification reversal in China: indicators and methods review

With gradual emergence of desertification reversal after inception of combative attempts in China, its evaluation which is based on solid identification is imperative. However, either identification or evaluation lacks consensus and are limited in earlier studies. This paper endeavors to fill this gap by relying on a systematic review of recent studies. After a clarification of causal relation of identification and evaluation, an argument of indicators and models selection is presented taking sustainability, cost and benefits, public interest and individual behavior into account. At first, we emphasize the logical and sequential importance of identification as prerequisite of evaluation, and demonstrate that fundamental identification could be operated by both direct and indirect implementations, though direct implementation usually seems to be a favorite al- tel＇native. Here, we emphasize a consideration of sustainable development, cost and benefits, public interest and individual behaviors together, due to the hiatus of incorporating economic and ecological segments together, and the innate theoretical deficiencies on environmental products of traditional economic and ecological methods of evaluation. Thus, we conceptually merge the economic and ecological segments into one theoretical framework. However, no matter how elaborate the models is, there is an apparent gap of both identification and evaluation due to failure of dynamic interpretations, thereby, it may be future trend and urgency on models＇ elaboration.