川滇地区中小震地震动衰减特征分析

利用2007年以来川滇地区24次中小型破坏性地震(Ms4.7～6.7)的基岩场地和土层场地的强震动记录,分别统计获得了川滇地区水平向基岩场地和土层场地的地震动峰值及加速度反应谱衰减关系.通过与俞言祥等2006年基于转换方法得到的我国西部基岩地震动衰减关系的对比,验证了本文衰减关系对利用中小地震进行地震动估计的可靠性.同时,根据强震动数据随震级以及震中距的分布,分析了本文结果的适用性和可靠性.     

民乐-山丹地震的区域构造变形背景与中短期前兆

利用青藏块体北缘地区2001～2003年GPS水平运动资料和1988—2003年跨断层短水准流动观测资料，借助改进的负位错模型及断层形变应变强度比一时变曲线，研究了与2003年10月25日民乐-山丹Ms6．1，Ms5．8地震孕育有关的区域构造变形背景与中短期前兆异常。分析表明，在昆仑山Ms8．1大震引起的大区域形变调整-短期松弛-开始恢复的背景下，民乐-山丹地震震源位于可能反映应变能积累加速的块体边界压性锁定段之间的剪应力强度增强段北侧；距震中最近的石灰窑口跨断层短水准流动场地在震前3个月呈现显著应变强度比异常，而震前10余天至数月内整个监测区异常个数、震前3个月相对近源区异常集中与局部增强均是对这两次地震的某种预示。     

豫西熊耳山青岗坪金矿床特征及其稳定同位素研究

青岗坪金矿为缓倾式构造蚀变岩型金矿床,具产状干缓、矿体薄、品位高、延伸长的特点。成矿物质主要来源于花山花岗岩,是燕山期花岗岩浆活动的产物,具有大中型矿床成矿条件。     

二叠纪海相碳酸盐的锶同位素演化及其意义

本文从沫阳和熊家场剖面二叠纪海相碳酸盐和玄武岩的锶同位素变化出发,讨论了碳酸盐的锶同位素组成与峨嵋山玄武岩喷发之间的关系,以及玄武岩中海相碳酸盐的锶同位素贫化原因,指出海相碳酸盐的锶同位素组成可作为了解地球构造演化的工具。     

河北省石人沟地区麻粒岩-紫苏花岗岩套岩石的矿物学和结晶温压条件

研究区内广泛出露的太古代岩石属于迁西群麻粒岩,包括麻粒岩、紫苏花岗岩、辉石-斜长片麻岩、角闪岩等。对这些岩石中辉石、角闪石、黑云母等矿物的研究结果表明,这些矿物具有明显的麻粒岩相成因特征,角闪石、黑云母同辉石等平衡共存。紫苏花岗岩中矿物除有序度增高外,其他特征与麻粒岩、片麻岩中的矿物相似。 根据矿物对地质温压计计算得到:本区第一期变质作用p-t条件为770-870℃,7.2-8.4k bar第二期为740-760℃,6.6-8.4k bar;矿物氧同位素温度为470-570℃,代表另一次程度较低的变质作用。     

水准测量网监测在德州市地面沉降中的应用

山东地面沉降灾害以鲁北平原最为严重,在德州地区的地面沉降已对当地人民的正常生产和生活构成了威胁,并制约了当地经济的可持续发展。通过建立水准测量网络及监测运行,查明了德州市地面沉降的规模和范围,研究成果表明工作区均存在地面沉降现象,截至2010年,德城区由于地下水开采强度大,地面沉降幅度最大,目前地面累计沉降量为-1186．9～-636．9mm,多年平均沉降速率为59．35mm／a,形成了以市区西北部为中心的地面沉降盆地。超量开采深层地下水是造成大规模地面沉降的重要因素。     

Geochemistry of meta-volcanic rocks from the Longbohe Cu deposit, Yunnan Province, China： Implications for the genesis and tectonic setting

The Longbohe Cu deposit, which is located in the southern part of the Honghe ore-forming zone, Yunnan Province, China, belongs to a typical ore field where volcanic rocks are of wide distribution and are associated with Cu mineralization in time and space. The volcanic rocks in the ore field, which have experienced varying degree of alteration or regional metamorphism, can be divided into three types, i.e., meta-andesite, meta-subvolcanic rock and meta-basic volcanic rock in accordance with their mineral assemblages. These three types of volcanic rocks in the ore field are relatively rich in Na and the main samples plot in the area of alkali basalts in the geochemical classification diagram. With the exception of very few elements, these three types of volcanic rocks are similar in the content of trace elements. In comparison to the basalts of different tectonic settings, the meta-volcanic rocks in the ore field are rich in high field strength elements (HFSE) such as Th, Nb, etc. and depleted in large ion lithophile elements (LILE) such as Sr, Ba, etc. and their primary mantle-normalized trace element patterns show remarkable negative Th and Nb anomalies and negative Sr and Ba anomalies. These three types of volcanic rocks are similar in REE content range and chondrite-normalized REE patterns with the exception of Eu anomaly. Various lines of evidence show that these three types of volcanic rocks in the ore field have the same source but are the products of different stages of magmatic evolution, their original magma is a product of partial melting of the metasomatically enriched mantle in the tensional tectonic setting within the continent plate, and the crystallization differentiation plays an important role in the process of magmatic evolution.     

松辽盆地北部宾参1井白垩系烃源岩的认识和评价及其意义

宾参1井是松辽盆地北部宾县断陷中的第一口参数井,钻遇白垩系地层,自下至上依次为沙河子组、营城组、登娄库组、泉头组和青山口组。在对宾参1井白垩系暗色泥岩进行一系列有机地球化学样品分析测试的基础上,从有机碳(TOC)、氯仿沥青"A"、有效碳(PC)、生烃潜量Pg(S1+S2)、热解峰温Tmax值、镜质体反射率(Ro)、烃源岩气相色谱特征、干酪根碳同位素特征、干酪根元素特征和源岩甾萜烷特征等方面着手,从有机质丰度、有机质类型和有机质成熟度三个角度认识该井白垩系烃源岩,并进行烃源岩的初步评价,认为:(1)青一段干酪根主要为Ⅱ1和Ⅱ2型,其中、下部已进入生油门限,属于非—差烃源岩,个别深度段为较好烃源岩,其上部及青二、三段处于未成熟阶段;(2)泉头组和登娄库组干酪根主要为Ⅲ型,已进入成熟生油阶段,前者属于非—差烃源岩,后者属于差烃源岩;(3)营城组和沙河子组干酪根主要为Ⅲ型,有些层段为Ⅱ2型,处于高成熟—过成熟阶段,以生气为主。对该井白垩系烃源岩的认识和初步评价为勘探程度极低的宾县凹陷含油气前景的评价预测和石油地质研究奠定了基础,具有现实意义和重要的理论意义。     

Characteristics of stable isotope and hydrochemistry of the groundwater around Qinghai Lake, NE Qinghai-Tibet Plateau, China

The integrated use of isotopic and hydrochemical tracers is an effective approach for investigating complex hydrological processes of groundwater. The stable isotope composition and hydrochemistry of the groundwater around Qinghai Lake were investigated to study the sources and recharge areas. Most of the groundwater points lie close to the local meteoric water line, indicating that the ground waters were recharged primarily from precipitation in the basin, though it had undergone varying degrees of evaporation. The hydrochemical analysis showed that the groundwater was mainly freshwater and that the hydrochemical type was Ca–Mg–HCO₃; the results of the boomerang envelope model and solutes calculated indicated that the groundwater chemistry was mainly controlled by carbonate dissolution around Qinghai Lake. The recharge altitudes of groundwater were relatively low (at 3,400 m.a.s.l) on the northern shore of Qinghai Lake (locations G1 and G5), relatively high (above 3,900 m.a.s.l) on the southern shore (locations G3 and G4), and approximately 3,700 m.a.s.l on the western shore (location G2). Furthermore, groundwater samples from the fault zone (e.g., G3) would be recharged in part from fissure or inter-basin water. High salinity of groundwater on the western shore (location G2) was related with the evaporite dissolution, the groundwater is unsuitable for drinking, and the drinking water should be improved and enhanced in this area. Knowledge of our research can promote effective management of water resources in this cold and semiarid region and add new data to global groundwater database.     

新疆东天山中段金铜成矿系统研究

以构造动力学体制、成矿机理和含矿建造等为原则,将东天山中段铜金成矿系统划分为晚泥盆世—早石炭世板块碰撞体制下的大南湖—头苏泉岩浆热液金铜、早石炭世板内伸展体制下的阿齐山—雅满苏火山热液铜铁和早二叠世陆内造山体制下的康古尔塔格韧性剪切铜金三个成矿系统。以成矿系统的研究内容和方法为指导,阐述了各成矿系统的地质背景、成矿系统的时空特征、控制因素、成矿系统要素、典型矿床的剖析或成矿系统内各矿床特征的对比,建立了各成矿系统模型,并总结了成矿系统的演化过程和演化谱系。