The sulfur isotopic composition of sulfides from ores and host rocks of the Upper Kolyma region,Magadan Oblast

More than 200 analyses of the sulfur isotopic composition of sulfides from various terrigenous and intrusive host rocks, metasomatically altered wall rocks, and gold lodes of the Upper Kolyma region are presented. In accessory pyrite of the metaterrigenous rocks, δ³⁴S varies from ?23.1 to +5.7‰ δ³⁴S of pyrite and arsenopyrite from gold-quartz mineralization is within the range ?10.6 to ?0.4‰ and is close to the average δ³⁴S of pyrite from the metaterrigenous rocks (?4.4‰). In the intrusive rocks, δ³⁴S of pyrite varies from ?3.8 to +2.6‰ (+0.7‰, on average) and drastically differs from δ³⁴S of arsenopyrite from postmagmatic gold-rare-metal mineralization (?7.9 to ?2.7‰; ?5.2‰, on average). The comparison of the δ³⁴S of accessory sulfides from the host rocks with δ³⁴S of sulfides from the gold deposits suggests that sulfur mobilized from the terrigenous sequences participated in the hydrothermal process. The results obtained are consistent with the metamorphic model of the formation of gold-quartz deposits in the Upper Kolyma region.     

广西北海市地下水系统水化学特征的分析

对广西北海市近20年的地下水水质监测资料和2002-2003年野外实地取样的测试资料进行分析,并采用Piper图和Q型群分析进行水化学分类,结果表明该地区北部地下水以Ca·Na-HCO₃型为主,水化学特征显示地下水化学成分受降雨入渗和溶滤的影响,而南部地下水以Na-Cl或Na·Ca-Cl型为主。北海市天然条件下地下水的矿化度低,pH值低,呈偏酸性。低矿化度的雨水、可溶盐含量极低的含水介质、迅速的水循环以及长期的淋滤作用,导致了北海地区地下水低矿化度的特点。     

浙江瓶窑BHQ孔全新统孢粉组合特征与气候变化

利用浙江省瓶窑北湖BHQ孔长约14m的岩心,以4个AMS¹⁴C数据为年代依据,对49块样品进行孢粉分析。分析结果发现,样品中孢粉浓度差异较大,植物种类繁多,总计103个科/属。通过对孢粉组合特征的分析,结合岩性特征,划分出3个孢粉带和9个亚带,重建了研究区早—中全新世植被演替和气候冷暖波动的环境序列。19～8.9m沉积时段,对应于早全新世气候回暖期,研究区植被主要是以落叶栎、松、阿丁枫和枫杨为主,混有少量常绿栎和榆等的针叶—落叶阔叶混交林,常绿乔木花粉含量较低,说明研究区经历晚更新世晚期新仙女木事件后进入全新世,气候迅速转暖;8.9～6.7m沉积时段,对应于全新世最适宜期,为研究区水热条件配置最佳阶段,主要发育由落叶栎、常绿栎、松、阿丁枫、枫杨和榆等组成的常绿—落叶阔叶混交林,常绿乔木的种类和含量要远远高于前一阶段,指示气候变化的最适宜阶段;6.7～4.775m沉积时段,对应于中全新世气候波动期,孢粉组合发生明显波动,研究区植被主要以落叶栎、枫香、松、枫杨等落叶阔叶乔木为主,常绿栎花粉的含量急剧萎缩,表明研究区植被类型演替为落叶阔叶林,反映经历了较为剧烈的气候恶化事件,而本段高含量的稻属花粉(≥35μm)可能指示该时段研究区存在一定规模的古人类活动。     

卡基娃滑坡变形破坏模式数值模拟研究

特大型土质滑坡的破坏模式,通过现场调查辅以常规的钻探等手段,难以得到全面的认识。本文以四川凉山自治县木里乡卡基娃滑坡为例,应用FLAC3D 有限差分软件,结合该滑坡实际地质条件、地质模型,选择自重+暴雨及假设滑坡前缘被冲蚀条件自重+暴雨两种工况模拟研究该滑坡的稳定性及可能出现的破坏模式,揭露了该滑坡破坏中最大应力、位移。     

济南及周边地区大气气溶胶空间分布特征

利用北京人工影响天气办公室新引进的PMS粒子测量系统探测的气溶胶资料,分析了济南及周边地区的气溶胶空间分布特征,探讨了气溶胶与逆温层和大气温湿度的关系。结果表明,气溶胶粒子数浓度垂直分布存在较大的差异,逆温层的存在和相对湿度峰值对气溶胶的分布影响很大。逆温层附近和相对湿度峰值区会产生较高的气溶胶数浓度,造成气溶胶粒子的...     

区域资源环境承载力评价信息平台设计与实现

结合资源环境承载力综合评价技术与方法,设计开发了资源环境承载力评价信息平台。本平台主要实现了资源环境承载力基础数据管理、导入和导出、资源环境承载力评价8大类指标的计算及等级评价、评价结果展示等功能,最终实现资源与环境的科学管理和合理应用,为我国区域协调、生态安全、资源保证能力、重大设施建设、国土开发利用、国土资源规划提供信息服务。同时,也为资源环境承载力综合评价的研究工作提供技术支撑。     

用对氧的电子探针定量分析值测定石榴子石中Fe~(2+)与Fe~(3+)的含量

本文用对氧的电子探针定量分析值测定了几种石榴子石中Fe~(2+)与Fe~(3+)的含量,讨论了这种新方法中氧的测量精度,详细叙述了实验过程,并与常用的电价差值法和剩余氧计算法进行了比较。     

20世纪全球增暖最显著的区域

Having analyzed a global grid temperature anomaly data set and some sea level pressure data during the last century, we found the following facts. Firstly, the annual temperature change with a warming trend of about 0.6℃/100 years in the tropical area over Indian to the western Pacific Oceans was most closely correlated to the global mean change. Therefore, the temperature change in this area might serve as an indicator of global mean change at annual and longer time scales. Secondly, a cooling of about -0.3℃ / 100 years occurred over the northern Atlantic. Thirdly, a two-wave pattern of temperature change, warming over northern Asia and northwestern America and cooling over the northern Atlantic and the northern Pacific, occurred during the last half century linked to strengthening westerlies over the northern Atlantic and the weakening Siberian High. Fourthly, a remarkable seasonal difference occurred over the Eurasian continent, with cooling (warming) in winter (summer) during 1896-1945, and warming (cooling) in winter (summer) during 1946-1995. The corresponding variations of the North Atlantic Oscillation and the Southern Oscillation were also discussed.     

U-Pb (SIMS SHRIMP-II) age of volcanic rocks from the Tulukuev caldera (Streltsov Uranium-Ore Cluster,Eastern Transbaikalia)

The precision dating (U-Pb local by zircons, SHRIMP-II) of volcanic rocks in the unique uranium-bearing structure of Transbaikalia is performed for the first time. The basic conclusions are as follows. The volcanic activity in the Tulukuev caldera covers the period of not less than 30–35 mln years, within the period from (not later than) 162 to 128 mln years. Two stages of caldera evolution are established: the early (trachydacite-basalt) stage up to 154 mln years and the late (trachybasalt-rhyolite) stage from 142 to 128 mln years, with a 10 mln year break, which caused the deep erosion of the lower layer. Three phases of rhyolite magmatism are substantiated. The first one, 142 mln years, is the ejection of ignimbrites (microfelsitic rhyolites); the second one, 137–135 mln years, is the outflow of lavas of sanidine-morion rhyolites and subvolcanic and ring dyke intrusions. The third phase, 128 mln years, is connected with the occurrence of cesium-bearing perlites in the southwestern part of the caldera. The age of the granite-porphyries of the Krasnokamensk stock almost coincides with the precision data of the age of the uranium ores [4]. It is found that zircons from the granite-porphyries within the ore field of the Argunsk deposit have an anomalously high content of uranium. This fact can additionally testify to the time-and-spatial closeness of magmatism and processes of ore formation.     

Removal of Nitro Aromatic Compounds from 2,4,6‐Trinitrotoluene Red Water Using 1,2‐Ethanediamine Modified Macroporous Polystyrene Microspheres

To remove nitro aromatic compounds (NACs) from 2,4,6‐trinitrotoluene (TNT) red water, large‐pore‐size (pore size = 200 nm) polystyrene (PSt) microspheres were activated with chloroacetyl chloride followed by reaction with 1,2‐ethanediamine (EDA). Fourier transform IR analyses showed that the amino group was introduced onto PSt microspheres. Determination of the total amino group and primary amino densities suggested that the imino group was the functional group of EDA–PSt. Scanning electron microscope images and mercury porosimetry measurements indicated that the pore structure was well maintained during the reaction. After adsorption with EDA–PSt, 98.5% chemical oxygen demand and 99% acute toxicity of TNT red water was removed. As shown by HPLC and GC–MS, all the neutral and acid NACs in TNT red water were removed by EDA–PSt, while the basic NACs were not. The results showed that hydrogen bonding and electrostatic attraction were involved in adsorption. The adsorbed neutral and acid NACs were eluted using methanol and 0.1 mol L^?1 NaOH, respectively.