宇宙常数与宇宙年龄问题

本文用球对称扰动模型导出了星系暗晕的平均密度与形成时间的关系 ,并由此估算银河系的形成时间tV.我们把球状星团的年龄作为银河系年龄tG 的代表 ,则tG tV 是宇宙年龄 .对Ωλ=0 ,0 .7和 0 .8的平坦宇宙模型 ,本文计算并讨论了能与它相洽的哈勃常数的范围 .结果表明 ,若哈勃常数大到 80km·s- 1 Mpc- 1 左右 ,引入宇宙常数并不一定能解决宇宙年龄的矛盾     

Experimental Research on Microscopic Indicators of Temperature＇ s Returning-to-Zero in Deformation of Calcite and Discussions of Correlation Problem

In order to determine the degree of returning-to-zero of temperatures of deformed calcite, a series of rock-breaking experiments were designed to test calcite-rich limestone samples under fixed confining pressures and different temperatures. The consolidated deformed samples in their initial state were observed under a microscope and the microscopic indicators in different zero-returning states were put forward, thus providing a microscopic foundation for evaluation of reliability of dating values of deformation in calcite. At last, the correction of dating values of deformation for samples whose temperature has not yet returned to zero is discussed.     

周家塆岩体锆石年龄值及其地质意义

大别山麓前寒武纪变质岩分布区，具片麻状构造的花岗岩类分布较广。周家塆岩体即为一例。前人主要依据片麻理发育程度，以类比的声法，将这些片麻状花岗岩时代定为“大别-吕梁期”或“晋宁期”，而将周家塆岩体定为燕山早期花岗岩侵入体。这些结论，均缺乏同位素年龄数据佐证，有的也不切合地质实际，因而谬误不少。     

江苏省同位素地质年龄数据库建设

系统介绍了江苏省同位素地质年龄数据库的建库工作及取得的主要成果，并针对同位素地质年龄数据库、工作指南和同位素地质测年工作等方面存在的问题提出了对策和建议。     

Medical geology：new relevance in the earth sciences

The interdisciplinary fieldresponds to the need to betterof “Medical Geology“ understand the relationships between human health and our surrounding environment. The influence of earth resources, natural environmental factors and land-use on human health has long been recognized, dating back to ancient Rome and Peru‘s Inca civilization. Today links between the natural environment and health can be found throughout the world. This review introduces the historical context of this particular type of research, contrasts the direct geological and indirect natural hazard influences on healthas a framework of study, elaborates on pathways of elemental accumulation in the body and provides examples of specific geochemical behaviours and diseases that are often associated with either too much or not enough of certain elements which comprise the Earth.     

西天山达巴特火山岩的形成环境及对斑岩型矿化的制约

本文通过对西天山地区比较典型的达巴特斑岩铜钼矿床矿区范围内出露上的英安岩和花岗斑岩进行了系统的岩石地球化学分析,对英安岩和流纹斑岩中的锆石进行了SHRIMP U-Pb定年研究,分别获得了315.9±5.9Ma和278.7±5.7Ma。岩石化学、微量以及稀土元素特征表明从英安岩到花岗斑岩,岩体具有明显的分异演化特征和很好的继承性。火山岩和次火山岩的精确定年为准确厘定火山岩形成的时限和地球动力学背景提供了依据。结合已有的Re-Os法获得的矿化年龄,表明晚石炭世末-早二叠世初（278.7±5.7Ma）,西天山地区进入板块碰撞-板内伸展阶段,由于板内幔根的部分熔化,造成深源斑岩岩浆侵位,在达巴特矿区形成了由花岗斑岩、流纹斑岩和流纹质凝灰熔岩组成的椭圆形火山机构,并导致相关矿床的形成。     

华北克拉通北缘隆化地区S型花岗岩的独居石年龄图谱

位于华北克拉通北缘中段的隆化S型花岗岩由石榴石黑云母花岗岩、石榴石花岗岩以及片麻理化的黑云母花岗岩组成。其主体岩性石榴石黑云母花岗岩SiO_2和Al_2O_3含量分别为64.09%～69.6%以及14.6%～16.13%,K_2O/Na_2O>1.0,A/CNK>1,0,Mg~#在20.76～34.89之间变化,具有明显的Nb、Ta、P、Ti和Sr亏损以及Rb、K和Th富集。石榴石黑云母花岗岩(样品JB6031-1)采用独居石电子探针U-Th-Pb化学法进行测年,获得了2553±120Ma、2180±42Ma和1854±24Ma三个年龄峰值。一颗独居石内部成分分带上6个分析点定年结果构成2553±120Ma的峰值年龄,这一年龄与我们最新获得的2506±7Ma和2541±8Ma(继承锆石年龄)LA-ICP-MS锆石U-Pb同位素年龄相似,我们将这一独居石年龄解释为继承独居石的年龄,表明在赤城-隆化断裂以北存在太古宙陆块,并且在后期构造-热事件中发生部分熔融形成S型花岗岩。该独居石颗粒幔部成分分带上10个分析点的测年结果揭示的峰值年龄为2181±42Ma,该年龄也是出现频率最高的年龄值,我们建议2181±42Ma为S型花岗岩的结晶年龄,反映了S型花岗岩的侵位时代。独居石颗粒外部成分分带上8个分析点的测年结果构成1854±24Ma的峰值年龄,该年龄与华北克拉通中部带的变质年龄接近,我们将其解释为S型花岗岩的变质年龄,表明华北克拉通北缘的构造演化与中部带的构造演化密切相关。