三江地区澜沧江带南段南林山基性岩体锆石U-Pb年龄及岩石地球化学特征   总被引：4，自引：1，他引：3       下载免费PDF全文

李钢柱  苏尚国  雷玮琰  段向东 《地学前缘》2011,18(5):206-212

南林山基性岩体位于西南三江地区,岩体主要由辉长岩和闪长岩组成。通过ID-TIMS锆石U-Pb年代学方法对南林山岩体中闪长岩进行精确定年,获得其结晶年龄为（298.44±0.33）Ma,表明南林山基性岩体的形成时代为早二叠世。全岩主量、微量元素与稀土元素等研究表明,辉长岩和闪长岩总体上均呈现轻稀土元素（LREEs）相对于...  相似文献   

安徽凤阳石英岩的铁含量与磁化率的关系     

李勇  李海燕  赵应权  章毛连  刘慧  何恩节 《吉林大学学报(地球科学版)》2011,(Z1):133-140

利用电子探针检测安徽凤阳石英岩中的含铁矿物,测量由相同矿区的石英岩加工而成的不同粒度石英砂的Fe2O3质量分数(w(Fe2O3))与磁化率。结果表明:石英岩中有磁铁矿、黄铁矿、黑云母与白云母等多种含铁矿物。这些含铁矿物主要充填在石英颗粒孔隙中,粒度大多小于0.1 mm。而石英砂中的w(Fe2O3)普遍很低(小于0.1%),其磁化率主要受磁铁矿控制。并且不同粒度的石英砂中w(Fe2O3)与磁化率存在较大差异,当石英砂中的w(Fe2O3)大于0.01%时,由Fe2+、Fe3+磁性离子含量决定磁化率大小,两者存在强正相关关系。这也反映出了石英岩的铁含量与磁化率之间的关系。因此,磁化率可作为石英岩铁含量的替代性指标。  相似文献   

海相油页岩的生烃动力学特征——以燕山地区下马岭组油页岩为例     

刘岩  钟宁宁  宋涛  田永晶  韩辉  朱雷 《吉林大学学报(地球科学版)》2011,(Z1):78-84,113

油页岩是未来重要的补充与替代能源。通过开放体系程序升温热模拟实验,对燕山地区下马岭组海相油页岩进行了研究。结果表明:其热裂解反应主要发生在440～480℃,表观生烃活化能集中分布于170～290 kJ/mol,主峰约为240 kJ/mol,明显高于陆相油页岩(抚顺油页岩和茂名油页岩),而与下古生界海相烃源岩(甘肃平凉奥陶系灰岩及爱沙尼亚奥陶系Kukersite油页岩)活化能分布范围及主峰位置相似。以ICP技术规范为例,在相同热历史条件下,通过数值模拟认识到下马岭组海相油页岩主生烃温度为275～325℃,高于湖相油页岩(265～305℃),而与下古生界海相烃源岩相似,表明其可能具有与古生界海相有机质相似的生烃机理。  相似文献   

探地雷达在冰川厚度及冰下地形探测中的应用     

王璞玉  李忠勤  吴利华  李慧林  王文彬  王飞腾 《吉林大学学报(地球科学版)》2011,(Z1):393-400

探地雷达因其快速、准确、无损、高分辨率等优势而被广泛应用于冰川学领域。以天山托木尔峰青冰滩72号冰川为例,着重介绍了探地雷达在冰川厚度及冰下地形探测中的应用。通过对雷达图像的处理和解译,获取了高精度的冰川厚度数据,恢复了冰下地形,计算了冰储量,并分析了冰川厚度变化对气候变化的响应。结果表明:冰舌厚度为0～148 m;冰储量为0.055 860 km3,折合成水为0.050 274 km3。近50年来,该冰川呈现强烈消融,与冰川区气温快速上升有直接关系,雷达探测为研究此响应机制提供了定量化的科学依据。  相似文献   

干旱区机械化集雨整地造林效果分析——“瓦勒拉尼系统”集雨造林效果研究     

王君厚  董建林  李忠平  赵中南  赵有贤  赵国君  王树元  王永民  林景友  庞秀谦 《中国沙漠》2011,31(5):1260-1266

 从2006年到2009年,中国国家林业局与意大利环境国土海洋部合作,应用意大利机械化集雨抗旱整地造林技术——“瓦勒拉尼系统” 在内蒙古赤峰市进行造林试验示范。与传统的人工整地造林相比,降水利用率提高两倍,土壤紧实度降低82%,土壤含水率平均提高60%,造林成活率提高30%左右。对“瓦勒拉尼系统”整地造林各项技术参数的测试分析表明,该系统具有深耕集雨、快速高效、经济实用、适应性强等特点。该系统在集雨抗旱造林方面具有的优越性和先进性,为该系统在中国干旱区推广应用提供了科学依据和实用技术方法。  相似文献   

不同无机氮浓度下中肋骨条藻和三角褐指藻生长对生长环境pH的影响     

苟彬  高永利  殷克东  蔡卫君 《热带海洋学报》2011,(3)

海洋酸化是当前一个严重的环境问题,而海水pH的变化与微藻生长时对溶解无机碳的吸收有关。在室内条件下采用生理生态学方法,研究中肋骨条藻Skeletonema costatum和三角褐指藻Phaeodactylum tricornutum在不同无机氮水平下生长到最大生物量时培养液pH的变化。结果表明,培养液无机氮浓度从10μmol.L-1上升到200μmol.L-1过程中,2种微藻的叶绿素浓度和最终pH均呈上升趋势。培养液pH的增加量与无机氮的消耗量呈正相关关系,培养液pH的增加量与溶解无机碳的消耗量也呈正相关关系。  相似文献   

A semi-implicit three-dimensional numerical model for non-hydrostatic pressure free-surface flows on an unstructured,sigma grid   总被引：1，自引：0，他引：1  

De-chao HU  De-yu ZHONG  Guang-qian WANG  Yong-hui ZHU 《国际泥沙研究》2013,28(1):77-89

A semi-implicit 3-D numerical formulation for solving non-hydrostatic pressure free-surface flows on an unstructured,sigma grid is proposed.Pressure-splitting and 9 semi-implicit methods are inherited and reformed from Casulli’s z-coordinate formulation.The non-orthogonal sigma-coordinate transformation leads to additional terms. The resulting linear system for the non-hydrostatic correction is diagonally dominant but unsymmetric,and it is solved by the BiCGstab method.In contrast with z-coordinate non-hydrostatic models,the new model fits vertical boundaries much better,which is important for the long-time simulation of sediment transport and riverbed deformation.A lock-exchange density flow is computed to determine whether the new scheme is able to simulate non-hydrostatic free-surface flows.The new model is further verified using the field data of a natural river bend of the lower Yangtze River.Good agreement between simulations and earlier research results,field data is obtained, indicating that the new model is applicable to hydraulic projects in real rivers.  相似文献   

A toxicological study of inhalable particulates by plasmid DNA assay:A case study from Macao     

SHAO LongYi  SHEN RongRong  WANG Jing  WANG ZhiShi  TANG Uwa  YANG ShuShen 《中国科学:地球科学(英文版)》2013,(6):1037-1043

Oxidative damage to plasmid DNA induced by airborne PM 10(particulate matter with an aerodynamic diameter of 10 μm or less) is caused by the bioavailable(i.e.,soluble) heavy metals on the particle surface.However,quantitative analyses of the links between PM 10 and oxidative damage are limited.In this study,plasmid DNA assay and ICP-MS were applied to study oxidative capacity and trace element compositions,respectively,of summer and winter PM 10 samples collected at several sites(Sun Yat Sen Municipal Park(SYSP) and Av.de Horta e Costa(AHC) on the Macao peninsula and Macao University on Taipa Island(TI)) in Macao.At AHC and TI,the oxidative capacity of PM 10 collected in winter was higher than that collected in summer,for both the whole sample and the water-soluble fraction.In contrast,no seasonal variation was noted at SYSP.PM 10 exhibited the highest oxidative capacity at SYSP and lowest oxidative capacity at TI in both seasons,demonstrating that the PM 10 collected on the Macao peninsula had a higher toxicity than that from Taipa Island.ICP-MS analyses revealed that the concentrations of total analyzed trace elements and their water-soluble components in PM 10 from TI and AHC were higher in winter than in summer,whereas SYSP displayed the opposite trend.The extents of oxidative damage induced by the water-soluble fractions and intact whole particles were generally similar,implying that the oxidative damage caused by particles in Macao resulted mainly from the water-soluble fraction.The oxidative capacities of PM 10 were positively correlated with both whole and soluble Zn at the 95% confidence level,indicating that Zn was the major element responsible for the oxidative damage caused by particles in Macao.Other heavy metals,such as Cr,Cu,Cd,Ni,As,and Pb,also exhibited elevated concentrations,and the potential health impacts of these metals should be considered.  相似文献   

Cementation and diagenetic fluid of algal dolomites in the Sinian Dengying Formation in southeastern Sichuan Basin   总被引：3，自引：0，他引：3  

SHI ZeJin  WANG Yong  TIAN YaMing  WANG ChangCheng 《中国科学:地球科学(英文版)》2013,(2):192-202

The Sinian Dengying Formation in China hosts one of the oldest gas-bearing reservoirs in the world.With a long geological history,it has developed into the reservoir rocks,whose quality depends on chemical dissolution and cementation.Despite presence of cavities and pores in the algal dolomites of the Dengying Formation,they were mostly filled with various forms of dolomite cements.Therefore,the investigation of these dolomites and their evolution is significant for analyzing the mechanism of pore space preservation.There are five types of cements in the Dengying Formation,which were well sampled for lab measurements such as thin section,cathodeluminescence,minor elements,isotope analysis of carbon,oxygen and strontium,in attempt to explore the fillers’ geochemical characteristics and the diagenetic fluids.They are characterized as follows:firstly,fibrous rim dolomite cement is a typical product formed at sea bottom,and geochemically very similar to the matrix(micrite and microcrystalline dolomite),which could be a reflection of the geochemical characteristics of water at that time;secondly,the diagenetic fluids of the foliated dolomite cements tend to be inheriting,derived from the shallow burial "imprisoned" seawater;thirdly,fine-to medium-grained dolomite cements with fairly high strontium isotopes and low carbon and oxygen isotopes were precipitated chiefly in freshwater during the period of uplifting caused by Tongwan tectonic movement;fourthly,coarse-grained dolomite cements bear a relatively high percentage of Mn element,but low in Fe and Sr,with carbon and oxygen isotopes remarkably shifted to negative values,which all show that they are related to hydrocarbon maturation and migration,and corresponding Thermochemical Sulfate Reduction;lastly,saddle-shaped dolomite cements are hydrothermally associated,and they were formed in high-temperature brine,which had passed through the areas rich in radioactive strontium isotopes.  相似文献   

Water-enhanced plastic deformation in felsic rocks   总被引：1，自引：0，他引：1  

HAN Liang  ZHOU YongSheng  HE ChangRong 《中国科学:地球科学(英文版)》2013,(2):203-216

Using Fourier transform infrared spectroscopy(FTIR),we measured water contents in quartz and feldspar for four kinds of felsic rocks,i.e.,undeformed granite,banded granitic gneiss,fine-grained felsic mylonite,and fine-grained quartz-mica schist,collected from Pengguan Complex and Kangding Complex in the Longmenshan tectonic zone,Sichuan,China.The absorbance spectra suggest that water in coarse-grained quartz and feldspar of undeformed granite and banded granitic gneiss occurs mainly as hydroxyl in crystal defects,and water in most of fine-grained quartz and feldspar of felsic mylonite is molecular water in inclusions and liquid-type water in grain boundaries,but in some cases it still occurs as hydroxyl in crystal defects.Water content of quartz in undeformed granite is 0.001 wt%-0.009 wt %,and that of feldspar 0.005 wt%-0.02 wt%.The banded granitic gneiss shows water contents of 0.002 wt%-0.011 wt% in quartz and 0.012 wt%-0.036 wt% in feldspar.Quartz ribbon and feldspar ribbon in fine-grained felsic mylonite show that their water contents are similar to those of coarse-grained quartz and feldspar in granite,0.002 wt%-0.011 wt%,and 0.004 wt%-0.02 wt%,respectively.Water contents of fine-grained quartz and feldspar are respectively 0.004 wt%-0.02 wt% and 0.012 wt%-0.06 wt%.Water content of quartz in fine-grained quartz-mica schist is 0.007 wt%-0.15 wt%.Water-bearing minerals display much higher water contents than those of nominally anhydrous minerals,and the percentage of water-bearing minerals in felsic rocks increases with the strain of rocks.These new data indicate that hydroxyl in crystal defects has basically not been released during the shear deformation,and on the contrary,the increase in molecular water in inclusions and liquid-type water in grain boundaries as well as water-bearing minerals after shear deformation leads to a significant increase of the water content in deformed rocks.Based on data of creep tests,it is inferred here that the fine-grained mylonites with more water have much lower strength than that of the weakly deformed coarse-grained rocks in the middle crust,and this indicates that trace amount of water significantly helped develop the ductile shear zone.  相似文献