中国内陆干旱、半干旱区苦咸水分布特征

通过大量野外调查、水样采集和化验分析,对中国内陆干旱、半干旱区的苦咸水和高氟水分布特征进行了初步研究。采集到的地表和地下水样中,分别有51.0%和41.5%属于苦咸水;55%和59%水样氟化物含量超标,属于高氟水。研究区的苦咸水以Cl^--Na⁺和HCO₃^--Na⁺为主要离子类型,SO₄^2--Mg²⁺和SO₄^2--Ca²⁺为次要离子类型。苦咸水和高氟水主要分布在内陆河流域下游尾闾、封闭内流区低洼湖盆低地、北部准平原化干燥剥蚀低山残丘间冲积洼地、沙漠低洼湖盆和黄土高原中西部径流系数较小的河流及部分露头潜水等区域,并具有区域富集性分布特点。季节性降水、季节性河流或渠系灌溉对苦咸水的季节性或年际间变化和空间分布有较大影响。较高浓度基质含盐量、水文地质结构、气候条件和特定的水文地球化学环境是苦咸水和高氟水形成与富集分布的主要原因。     

热液成因有色金属矿多维异常体系:以马头斑岩型钼铜矿为例

从深部矿地球化学勘查实际需求出发,根据近年来20余个矿床研究结果,总结提出了热液成因有色金属矿床矿致异常规律--多维异常体系。多维异常体系是指产出在特定成矿地质时期地质体中,空间有序共存、形成机理各异、成矿指向递进的多属性地球化学异常体系,将在斑岩型、矽卡岩型、热液型以及沉积改造型等与热液作用有关的有色金属矿产深部矿预测和评价中发挥重要作用。以安徽马头斑岩型钼铜矿为例,对该矿床多维异常体系进行了探讨。结果表明: 在该矿床中,存在着以Na₂O为代表的负异常体系、以S为代表的矿化剂元素异常体系、矿化剂元素S与Fe和成矿元素间协同平衡体系、成矿及其伴生元素异常体系等,这些异常体系对成矿的指示作用是递进的,从而证实了多维异常体系的存在。对应用多维异常体系思路预测和评价深部矿进行了说明。     

华南北部湾盆地的形成机制

从北部湾盆地的区域地质构造背景、几何形态、边界断裂及内部断裂特征解析,综合沉积中心迁移规律及盆内构造研究,提出北部湾盆地为右行右阶走滑拉分成因。盆地的形成和发展受控于合浦-北流、信宜-廉江、吴川-四会和阳江-河源4条深大断裂带,这4条主干断裂带构成右阶断裂格架。古近系出现的花状构造等表现出典型的张扭特征,新近系受到压扭作用改造发生挤压反转,该盆地构造演化过程与华南大陆中、新生代拉分盆地具有同期性和相似性。中生代基底中先存的深大走滑断裂带是新生代北部湾盆地形成的先决地质条件。而印度-澳大利亚板块对欧亚板块碰撞挤压作用的逐渐增强和太平洋板块俯冲方向的改变及俯冲作用的衰减是控制北部湾盆地形成演化的区域大地构造因素。     

网络环境下地震科技信息资源建设初探

本文就网络环境下地震科技信息资源建设中的信息组织及资源共享等问题进行探讨。     

DLS型高精度多功能拾振器的设计与应用

文中介绍了新研制的便携式高精度多功能拾振器的技术性能、工作原理和理论计算,分析讨论了仪器的特点,给出了技术指标实测结果并进行了结构微振动记录幅值谱分析。     

热红外极轨卫星地震监测系统综合技术研究

以2003年架设的NOAA／FY极轨卫星数据地面接收站为基础,针对NOAA系列卫星．采用分布式处理方案,设计并建立了地震热红外卫星监测业务运行系统。系统主要功能包括：卫星数据的接收、处理、归档、查询、发布;自动生成全国夜晚地表亮温图像、全国白天彩色合成图像、全国每旬无云地表亮温图像等专题数据库产品;对任意选定的监测区进行热红外亮温动态跟踪和异常警示;实现了直观的无人值守的准实时自动化处理以及远程管理和数据检索。通过对地震热红外卫星监测业务运行系统的研究和开发,在数据标定、辐射校正、图像预处理、专题产品的生成与管理等方面取得了宝贵的经验,为我国地震卫星地面数据接收、处理系统的建立奠定了基础。     

The Taihua group on the southern margin of the North China craton: further insights from U–Pb ages and Hf isotope compositions of zircons

The "Taihua Group" is a collective term for a series of old terranes scattered along the southern margin of the North China Craton. The timing of formation and thermal overprinting of the Taihua Group have long been contentious, and its relationship with the Qinling orogenic belt has been unclear. In this study, new data from integrated in-situ U–Pb dating and Hf isotope analysis of zircons from an amphibolite (from the Xiong’ershan terrane) and a biotite gneiss (from the Lantian-Xiaoqinling terrane) indicate that the Upper Taihua Group formed during the Paleoproterozoic (2.3–2.5 Ga) and thus was originally part of the southern edge of North China Craton, detached during the Mesozoic Qinling orogeny and displaced about 100 km north from its original location. This suggests that the Taihua Group became part of the tectonic terrane associated with the Qinling orogeny and now forms part of the overthrust basement section of the Qinling belt. Before the Qinling orogeny, the Taihua Group was metamorphosed at 2.1 Ga. The initial Hf-isotope compositions of zircons, together with positive εNd(t) values for the whole-rocks, imply that the original magmas were derived from a juvenile source with some assimilation of an Archean crustal component.     

Contamination,chemical speciation and vertical distribution of heavy metals in soils of an old and large industrial zone in Northeast China

Heavy metal pollution of soils has become a major concern in China as a consequence of rapid urbanization and industrialization in recent years. However, the evaluation on soil heavy metal pollution in Shenyang, the largest heavy industrial base city in China, has not yet been conducted. In this study, accumulation, chemical speciation, and vertical distribution Cu, Zn, Pb and Cd in soils were studied and pollution condition was assessed in Tiexi Industrial District of Shenyang, the largest and oldest industrial zone in Northeastern China. The results showed that in topsoil, the average concentration of total Cu, Zn, Pb, and Cd was 209.06, 599.92, 470.19 and 8.59 mg kg⁻¹, respectively, much higher than the national threshold limit. The values of pollution index and integrated pollution index showed that the pollution level was Cd > Cu > Zn > Pb, and Cd, Cu and Zn belong to heavy pollution level. The residual, Fe and Mn oxide-bound, and organic-bound species accounted for about 90%, while carbonate-bound and exchangeable species accounted for about 10%. This study indicates that the soils in the industrial zone were widely and extremely polluted by multi-heavy metals as a result of long-term industrial activities.     

龙门山小鱼洞断裂在汶川地震中的地表破裂及地质意义

在龙门山中段小鱼洞地区映秀－北川断裂和彭县－灌县断裂发生了同震位移,同时在该地区新出现了一条北西向的同震破裂带——小鱼洞断裂的破裂带,并分割了两条近于平行的北东向逆冲－走滑型的主断裂。汶川特大地震发生后重点对小鱼洞断裂的地表破裂开展了详细的野外地质填图,利用全站仪和GPS对地表破裂进行了精确的测量。初步调查的结果表明,小鱼洞断裂位于映秀－北川断裂与彭县－灌县断裂之间,走向近于北西向,延伸约15km,以脆性破裂为特征,穿过小鱼洞大桥,并切割了多种类型的地貌单元,使道路发生拱曲、破坏和桥梁垮塌或移位。单个破裂长度在几米到300m不等,其南西盘为上升盘,北东盘为下降盘,平均垂直位错为1.0m,平均水平位错为2.3m,垂直与水平位错量之比1 ∶1～1 ∶2,显示为逆冲分量小于或等于左旋走滑分量,并以左旋走滑作用为主。同时,研究表明小鱼洞断裂属于映秀－北川断裂与彭县－灌县断裂之间的捩断层,其主要特征包括： 1)是在汶川地震中由于龙门山逆冲体之间的差异逆冲运动过程中而形成的断裂; 2)其走向近于北西向,垂直于龙门山北东向的主干断裂,而平行于逆冲体的逆冲运动方向; 3)具有高角度断面的断层,以左旋走滑作用为主。