嵩县雷门沟金矿地质特征及次生富集作用     

许令兵  刘国华 《河南国土资源》2001,(1)

本文从三条典型含金蚀变破碎带入手 ,通过对其次生富集带的分析、对比、归纳 ,揭示出次生富集带的深度、厚度和品位变化规律 ,并进一步从理论上阐明次生富集带的形成机理。  相似文献   

阿尔金北缘地区剥离断层控矿和金矿成因——以大平沟金矿床为例   总被引：5，自引：0，他引：5  

陈宣华  杨风  王小凤  陈柏林  陈正乐  王克卓 《吉林大学学报(地球科学版)》2002,32(2):122-127

阿尔金北缘大平沟金矿床是近年来在阿尔金山地区新发现的首例岩金矿床。为了阐明其矿床地质特征及其成因,采用构造解析与矿主档学研究相结合的方法。结果表明,（1）金矿物主要为金－银系列矿物,成色在915－946之间,金含量与K2O、Fe2O3呈正相关关系;（2）变粒岩、强片理化变粒岩、含金石英脉和无矿化纯净石英脉的稀土元素配分型式具有相似性;（3）主要成矿期温度范围198－290℃,为中温热液矿床;（4）成矿深度为1.77-2.68km;（5）氢氧同位素组成具有以岩浆水为主的特征。由此认为,大平沟金矿床是受阿尔金北缘断裂－剥离断层控制的金矿床,是该地区金矿找矿的方向。  相似文献   

论中国东部大型盆地区及邻区地质-地球物理复合尺度解析   总被引：7，自引：3，他引：4  

杨宝俊  张梅生  王璞珺  刘财  孙晓猛  焦新华  单玄龙  孟令顺  刘万崧  许文良  郭华 《地球物理学进展》2002,17(2):317-324

作为对中国东部陆缘地带大型盆地区及邻区地质－地球物理综合研究的部分结果,本文的基本认识：（1）穿过松辽盆地的1孙吴－双辽断裂可能是东倾伯低角度壳内断裂;（2）松辽盆地和渤海湾盆地可能属于“混合型裂谷盆地”;（3）东海盆地台北坳陷处在多期次张性应力场环境中,使在其西部附近产生张性正断层系;（4）欧亚大陆东部新生代区域构造运动总体处于右旋走滑拉张环境,其动力因素包括板块运动和地幔物质运动;（5）研究区莫霍面具有较为复杂的变化;（6）复合尺度研究方法是地质－地球物理综合分析的必要手段。  相似文献   

山东北部全新世的人地关系演变: 以海岸变迁和海盐生产为例   总被引：1，自引：0，他引：1       下载免费PDF全文

王青  朱继平  史本恒 《第四纪研究》2006,26(4):589-596

根据先秦考古遗址地理分布的分析和郭井子贝壳堤的发掘和调查,复原了6.5~5.0kaB.P. ,4.5~4.0kaB.P.和3.4~2.1kaB.P.的3条海岸线,它们大致与现代海岸线平行分布,年代自南向北逐渐年轻,揭示了山东北部地区全新世海侵和海退过程的主要环节,恢复了全新世海岸变迁的具体历程。对寿光大荒北央遗址出土盔形器内壁凝结物的XRF和XRD分析证明,本区沿海商周时期遗址出土的盔形器应是制盐器具,而沿海盔形器密集分布区与6.5~5.0kaB.P.的海岸线基本重合,表明商周时期海盐生产地域应在6.5~5.0kaB.P.和3.4~2.1kaB.P.的两条海岸线之间。本区的海盐生产与海岸变迁密切相关,人类适应环境和开发资源的主要手段就是从事海盐生产。在6.5~4.0kaB.P. ,人类在滨海地带有了初步的海盐生产,开始了适应环境和利用自然资源的最早尝试,在3.4~2.1kaB.P. ,人类又开始开采地下卤水生产海盐,使现今海拔9~10m以下的广阔地区成为产盐区。本区内陆的山前平原地带则是海盐的主要消费区,也是产盐区所需粮食和各种生产生活用品的供应区。这一分析对研究本区先秦时期的聚落功能演变具有重要意义,也是研究本区全新世人地关系演变的关键视角。  相似文献   

Correlation of atmospheric visibility with chemical composition of Kaohsiung aerosols   总被引：2，自引：0，他引：2  

Chung-Shin Yuan  Chang-Gai Lee  San-Ho Liu  Jui-cheng Chang  Ching Yuan  Horng-Yu Yang   《Atmospheric Research》2006,82(3-4):663

The objective of this study was to investigate the correlation of visibility with chemical composition of Kaohsiung aerosols. Daytime visibility was observed around noon at two observation sites in metropolitan Kaohsiung, Taiwan in the years of 1999 and 2000. Both seasonal and diurnal variation patterns of visibility were observed in the region. Ambient aerosols were sampled and analyzed for 11 constituents, including water-soluble ionic species (Cl⁻, NO₃⁻, SO₄⁻², NH₄⁺, K⁺, Na⁺, Ca⁺², and Mg⁺²) and carbonaceous contents (OC, EC, and TC), to characterize the chemical composition of Kaohsiung aerosols. Furthermore, a stepwise multiple linear regression model was developed to elucidate the influence of aerosol species on visibility impairments. The results showed that sulfate was the dominant species that affected both light scattering coefficient and visibility. On average, the percentage contributions of visibility degrading species to light scattering coefficient were 29% for sulfate, 28% for nitrate, 22% for total carbon, and 21% for PM_2.5-remainder. An empirical regression model of visibility based on sulfate, nitrate, and relative humidity was also developed. The model showed that sulfate in PM_2.5 was the most sensitive species to visibility variation, suggesting that the reduction of sulfate in PM_2.5 could effectively improve the visibility of metropolitan Kaohsiung. During the investigation period, an event of Asian dusts intruded metropolitan Kaohsiung and dramatically increased the aerosol loadings, especially in the coarse particles. However, local visual air quality did not degrade accordingly during the Asian dust event because both visibility and light scattering coefficient are affected mainly by the fine particles. The results are discussed in detail in the paper.  相似文献   

大庆采油一厂GIS数据查询与维护模块的设计与实现     

刘丽华 《测绘与空间地理信息》2007,30(3):68-70

利用VB在GeoStar地理信息系统开发平台上进行二次开发,实现大庆油田采油一厂水泡子地理信息系统的3维数据查询与维护。介绍了系统的模块组成和功能,以及实现各项功能的关键技术。该系统灵活实用、功能较全,通过实际生产应用,反映出在地面水域地理信息数据计算与管理、直观显示等方面具有很好的实用价值。  相似文献   

Coupled surface and ground water models for investigating hydrological processes     

Ray‐Shyan Wu  Dong‐Sin Shih  Ming‐Hsu Li  Chia‐Ching Niu 《水文研究》2008,22(8):1216-1229

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Composite analytical solutions for a soil vapour extraction system     

Jui‐Sheng Chen  Ching‐Ping Liang  Chih‐Yu Chen  Chen‐Wuing Liu 《水文研究》2007,21(11):1506-1516

Soil vapour extraction (SVE) is a common remediation technique for cleaning up unsaturated soils contaminated by volatile organic compounds (VOCs). Analytical solutions, which result from simple mathematical models, can allow the fast approximation of the time‐dependent effluent concentration and the gaining of insight into the processes that take place during soil remediation. Deriving the analytical solutions to advection–dispersion equations that simultaneously take into account the mechanical dispersion and molecular diffusion is very difficult because of the variable dependence of governing equations' coefficients. In this study, we first present two simplified analytical solutions that only consider mechanical dispersion or molecular diffusion. The two developed analytical solutions are compared with the numerical solution that simultaneously considers both mechanical dispersion and molecular diffusion to examine the applicability of the two simplified analytical solutions and distinguishes the individual contribution of the mechanical dispersion and molecular diffusion to total VOCs transport in an SVE system. Results show that dispersion plays an important role during SVE decontamination and neither the diffusion‐dominated solution nor the dispersion‐dominated solution can agree well with the numerical solution when both mechanical dispersion and molecular diffusion have significant contributions to the total VOCs transport flux. A composite analytical solution that linearly couples the diffusion‐ and dispersion‐dominated analytical solutions, which is proposed herein to eliminate the discrepancy between the analytical solutions and the numerical solution. Results indicate that the proposed composite analytical solution agrees well with the numerical solution and is an effective tool for quickly and accurately evaluating the time‐dependent effluent concentration for parameters of the different ranges of interest in an SVE remedial system. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Evidence for the 8,200 a <Emphasis Type="SmallCaps">b</Emphasis>.<Emphasis Type="SmallCaps">p</Emphasis>. cooling event in the middle Okinawa Trough     

Hua?YuEmail author  Yingqian?Xiong  Zhenxia?Liu  Serge?Berné  Chi-Yue?Huang  Guodong?Jia 《Geo-Marine Letters》2008,28(3):131-136

Based on new and existing data on oxygen isotopes, alkenone-surface seawater temperature trends, planktonic foraminifers, lithology, and clay mineral composition of piston cores, a distinct cooling event has been identified around 8,200 cal a b.p. in the middle Okinawa Trough, northwest Pacific. This corresponds to the 8,200 a b.p. cooling event recorded in many places of the Northern Hemisphere. During this event, the local temperature decreased by 1°C, and the δ¹⁸O value increased by 0.6‰. A strengthened Asian winter monsoon is the most probable cause for this event, which thus adds further credibility to the contention that we are dealing here with a global phenomenon.  相似文献   

额尔齐斯河上游西伯利亚云杉树轮宽度年表特征分析及其对气候的响应   总被引：1，自引：0，他引：1  

姜盛夏  袁玉江  喻树龙  张同文  陈峰  尚华明  张瑞波 《沙漠与绿洲气象(新疆气象)》2015,9(2):16-23

利用采自阿尔泰山南坡额尔齐斯河上游森林6个采样点的低海拔西伯利亚云杉（Picea obovata Ledeb）树轮样本,建立6个树轮宽度指数年表。分析标准化树轮宽度年表的特征参数及对气候的响应发现：（1）可可托海北（KKT）年表包含的气候信息最多,其次是塔里德萨依（TLD）年表。（2）6个标准化年表及区域年表（HEC）与临近的富蕴气象站与生长季及生长季前期的降水呈正相关,与上年7月到当年6月降水量相关最高达0.755,该研究结果与新疆天山山区云杉对气候的响应完全一致。降水是森林下限西伯利亚云杉树轮宽度生长的主要限制因子。（3）海拔相对较高的协特克阔依汗（XTK）和KKT年表除与其它年表具有对降水相同的响应特点外,还与当年8月的平均最低气温呈显著正相关。（4）区域年表树轮宽度指数经历了9个偏高时段和8个偏低时段,揭示了该地区降水的长期变化。  相似文献