冶勒电站库区水文地质条件的同位素研究

文章论述了四川冶勒电站库区内河水、泉水、承压水的同位素组成特征,讨论了泉水、承压水的补径排关系,确认了库区内河水和各层承压水之间不存在直接的水力联系,排除了河水向下渗漏的可能性。     

贵定超高有机硫煤硫的聚集模式

无论在化学上还是在地质学上,超高有机硫煤已很为人们关注.但现有的硫演化模式皆趋简单,远难以阐明煤中含量高达百分之十以上有机硫的聚集作用.其实超高有机硫煤的形成除了需特定的地质、物理化学、生物等条外,隐含于沉积泥炭中的是更复杂的硫元素变化.了解这种变化是认识超高有机硫煤成因的关键.稳定硫同位素作为一种有效的示踪手段.已     

浙江洋滨黄玉花岗斑石的Nd,Sr,Pb同位素研究

洋滨斑岩锡矿位于我国东南沿海中生代火山活动带中部。含矿岩石主要由含黄玉的钾长花岗斑岩与二长花岗斑岩及黄英斑岩组成。这些岩石具有高硅，强过铝质，富集不相容元素，弱的铈和强的铕负异常以及高的稀土总量特征。采用最小二乘法计算的全岩Ｒｂ－Ｓｒ等时线年龄为１０１．７±２．１Ｍａ，（＾８７Ｓｒ／＾８６Ｓｒ）ｉ＝０．７１４２±９。同时，它们具有低的εＮｄ值（－８．４～－８．０），较高的＾２０７Ｐｂ／＾２０４Ｐｂ     

世界首例独立碲矿的成矿年龄

四川石棉县境内的大水沟碲矿是目前世界首例也是唯一一例独立碲矿.矿床位于扬子地台西缘的康滇地轴内,并限定于中、下三叠统(T_1～2)变质穹窿体北翼的角闪石片     

湖相有机质的氢指数及碳同位素组成——湖面波动评价的指标——以RH孔为例

氢指数(HI)分析已广泛地用于油源岩的特性研究.由于HI分析用样量少、速度快、费用少和时间短等优点,已成为评价湖泊沉积环境的一种指标,并取得了良好的效果.本文根据RH孔沉积有机质的HI,结合本孔中总有机碳(TOC)含量及其δ~(13)C值的组成,讨论了RH孔中HI所指示的环境意义.1 样品与实验RH孔(33°54′N和102°32′E,3400m a.s.l.)位于青藏高原东部若尔盖盆地内,于1992年7月完钻,总进尺120.48m,取芯率在90%以上.RH孔顶部4.1m以上,用附近的天然剖面从层位上进行拼接.天然剖面取样38个,RH孔取样494个.     

重离子耗散撞同位素产物截面涨落的首次观测

近年来,在重离子耗散碰撞激发函数的测量中发现了一种新的截面涨落结构.一系列的实验已经证实,对于质量数A_1+A_2(?)100的较轻的核反应系统,这一现象具有普遍性,理论工作者也以极大的兴趣发展了好几种模型,解释并拟合了部分实验结果.这种研究提供了探讨双核系统的平均寿命、转动周期以及时间-空间分布性质的新方法.当前,理论与实验研究都十分活跃.最近,我们在北京原子能科学研究院的HI-13串列静电加速器上完成了~(19)F+~(51)V耗散反应类弹产物激发函数的测量,入射能量`从102.25 MeV到109.50MeV,步长250keV,     

Carbon isotopic record of foraminifers in surface sediments from the South China Sea and its significance

Since the 1990s, the papers and data involved withthe South China Sea (SCS) have been emerging in largenumbers in the world as people pay more attention to thepaleoceanography of the SCS. There have been more than100 cores mentioned in papers containing p…     

Helium isotopic compositions in fluid inclusions of the Gangxi fault belt in the Huanghua Depression, Bohai Bay Basin

Helium is a trace constituent in natural gases and is the lightest element of all rare gases. Formed during natural nuclear processes, helium is chemically stable. Due to its strong diffusibility and permeability, helium can be used as a very sensitive tracer. Helium has two natural stable isotopes, 3He and 4He. 3He originates from the universal nebulae when the earth was formed, and 4He mainly originates from the radioactive disintegration of elements in the crust, such as U and Th [1]. In…     

High resolution stalagmite δ18O records over the past 1000 years from Dongge Cave in Guizhou

Based on MC-ICP-MS U-series dating andstable O-isotope analysis results, a 4-5 years resolution monsoon record over the past 1000 years has been established for two stalagmites from Dongge Cave, Guizhou. The high resolution oxygen isotope record serves as a proxy for variations in rainfall of Asian southwest monsoon over the Yunnan-Guizhou Plateau. A close relation of the δ18O record with the A^14C record from tree rings largely reflects impact of centennial-scale solar activity on the monsoon climate changes. The conspicuous decrease in the δ18O value at AD 1720 indicates an abrupt increase in monsoon rainfall, suggesting that an atmospheric-oceanic couple over the tropical Indian Ocean plays an important role in rapid increase of the Northern Hemisphere temperature over the last century.