气候变化与人类活动对石家庄市藁城区地下水位埋深的影响分析     

闫佰忠  孙丰博  李晓萌  王玉清  范成博  陈佳琦 《吉林大学学报(地球科学版)》2021,51(3):854-863

为了探寻石家庄市藁城区地下水埋深动态变化规律,以藁城区2001—2018年的年降水量、地下水人工开采量等数据为基础,对藁城区地下水位埋深进行研究。首先采用P-Ⅲ型曲线法确定降水序列的丰、平、枯年份,分析不同降水量情况下地下水位埋深变化规律;其次,利用地下水开采潜力系数法和灰色关联度法对人工开采量和地下水位埋深的关系进行研究。结果表明：1）藁城区地下水位埋深在2001—2016年逐渐增大,在2016—2018年趋于减小,2016年为转折点;在空间上藁城区地下水位埋深呈现出北部埋深小、南部埋深大的特征,北部水位埋深较同期南部水位埋深要浅5~10 m。2）降水是驱动藁城区地下水位埋深变化的重要因素,枯水年水位埋深变幅在0.8~1.5 m之间,平水年水位埋深变幅在0.3~1.2 m之间,丰水年水位埋深变幅在0.3~1.1 m之间。主灌期（3—6月）的地下水位埋深增加速率均为cm/d级,非主灌期（7—10月）的地下水位埋深减少速率均为mm/d级。3）人工开采是驱动藁城区地下水位埋深变化的主导因素,其中农业开采量占人工开采量的80%。综上认为,藁城区一直处于严重超采状态,地下水累计超采量每增加1亿m³,地下水位埋深增加0.45 m。  相似文献   

Geology and mineralization of the Sanshandao supergiant gold deposit (1200 t) in the Jiaodong Peninsula,China: A review     

《China Geology》2021,4(4):686-719

The Jiaodong Peninsula in Shandong Province, China is the world’s third-largest gold metallogenic area, with cumulative proven gold resources exceeding 5000 t. Over the past few years, breakthroughs have been made in deep prospecting at a depth of 500–2000 m, particularly in the Sanshandao area where a huge deep gold orebody was identified. Based on previous studies and the latest prospecting progress achieved by the project team of this study, the following results are summarized. (1) 3D geological modeling results based on deep drilling core data reveal that the Sanshandao gold orefield, which was previously considered to consist of several independent deposits, is a supergiant deposit with gold resources of more than 1200 t (including 470 t under the sea area). The length of the major orebody is nearly 8 km, with a greatest depth of 2312 m below sea level and a maximum length of more than 3 km along their dip direction. (2) Thick gold orebodies in the Sanshandao gold deposit mainly occur in the specific sections of the ore-controlling fault where the fault plane changes from steeply to gently inclined, forming a stepped metallogenic model from shallow to deep level. The reason for this strong structural control on mineralization forms is that when ore-forming fluids migrated along faults, the pressure of fluids greatly fluctuated in fault sections where the fault dip angle changed. Since the solubility of gold in the ore-forming fluid is sensitive to fluid pressure, these sections along the fault plane serve as the target areas for deep prospecting. (3) Thermal uplifting-extensional structures provide thermodynamic conditions, migration pathways, and deposition spaces for gold mineralization. Meanwhile, the changes in mantle properties induced the transformation of the geochemical properties of the lower crust and magmatic rocks. This further led to the reactivation of ore-forming elements, which provided rich materials for gold mineralization. (4) It can be concluded from previous research results that the gold mineralization in the Jiaodong gold deposits occurred at about 120 Ma, which was superimposed by nonferrous metals mineralization at 118–111 Ma. The fluids were dominated by primary mantle water or magmatic water. Metamorphic water occurred in the early stage of the gold mineralization, while the fluid composition was dominated by meteoric water in the late stage. The S, Pb, and Sr isotopic compositions of the ores are similar to those of ore-hosting rocks, indicating that the ore-forming materials mainly derive from crustal materials, with the minor addition of mantle-derived materials. The gold deposits in the Jiaodong Peninsula were formed in an extensional tectonic environment during the transformation of the physical and chemical properties of the lithospheric mantle, which is different from typical orogenic gold deposits. Thus, it is proposed that they are named “Jiaodong-type” gold deposits.©2021 China Geology Editorial Office.  相似文献   

Chronostratigraphic constraints on Middle Pleistocene faunal assemblages and Acheulian industries from the Cretone lacustrine basin,central Italy          下载免费PDF全文

Fabrizio Marra  Piero Ceruleo  Brian Jicha  Luca Pandolfi  Carmelo Petronio  Leonardo Salari  Biagio Giaccio  Gianluca Sottili 《第四纪科学杂志》2016,31(7):641-658

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A 200-year precipitation index for the central English Lake District / Un indice de précipitation de 200 ans pour la Région des Lacs en Angleterre     

《水文科学杂志》2013,58(5)

Abstract

Abstract The geographical context and hydroclimatology of the English Lake District means that the region is an important monitor of changes to nationally significant environmental assets. Using monthly rainfall series for sites in and around the central Lake District, a continuous ~200-year precipitation index was constructed for a representative station close to Grasmere. The bridged series shows a significant decline in summer rainfall since the 1960s, offset by increases in winter and spring that are strongly linked to North Atlantic forcing. Over longer time periods, the index exhibits several notable dry (1850s, 1880s, 1890s, 1930s, 1970s) and wet (1820s, 1870s, 1920s, 1940s, 1990s) decades. These patterns are strongly reflected by reservoir inflow series and by indicators of the biological status of the region’s freshwater lakes. It is argued that long-term climate indices will become increasingly important as managers seek to evaluate recent and project environmental changes within the context of long-term natural variability.  相似文献   

金川超镁铁质岩体矿物化学特征及矿物地质温度计、压力计研究   总被引：4，自引：0，他引：4  

徐庆生  宋学信 《甘肃地质》1994,3(1):59-70

根据金川超镁铁质岩体主要造岩矿物和副矿物的共生组合关系及各种矿物的化学成分特点；选用５种较成熟、使用较方便的矿物地质温度计、压力计（主要是辉石温压计和角闪石压力计），对岩体形成的温、压条件进行了估算，其结果为：成岩温度为１０００～１３００℃（上限可到１４００～１５００℃），成岩压力约为５×１０￣８～１１×１０￣８ｐａ。金川超镁铁质岩体的主要岩石类型为尖晶石二辉橄榄岩，这一岩石类型在复杂体系相关系图中的稳定区域大致处于５×ｌ０￣８～１５×１０￣８ｐａ的范围，这与矿物温压计估算的成岩温压条件是一致的。  相似文献   

广州市环境噪声总体水平分析及其控制：以越秀区为例   总被引：2，自引：0，他引：2  

余汉豪 《热带地理》1995,15(2):103-108

随着广州市改革开放的深入发展，作为广州市中心区的越秀区环境噪声总体水平居高不下，而且还有上升趋势。本文分析了越秀区环境噪声现状和发展，对环境噪声总体水平的控制提出建议和对策。  相似文献   

Is there a metric for mineral deposit occurrence probabilities?     

Lawrence J. Drew  W. David Menzie 《Natural Resources Research》1993,2(2):92-105

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宣传贯彻《矿产资源法》促进依法治矿     

龚静夫 《湖南地质》1991,(1)

《矿产资源法》颁布实施五周年,通过宣传贯彻,增强了广大干部、群众依法办矿的法制观念,推动了各项矿管工作的开展,依法办矿的矿山取得了采矿权,非法采矿的小矿山被关闭,违法行为受到查处,矿管部门的声望越来越高,促讲了依法治矿。宣传贯彻《矿产资源法》要领导首先学法,提高认识,加强领导,建立一支专兼结合的宣传队伍,采取多种形式有重点地进行宣传教育。我国、我省面临矿产资源形势是严峻的,浪费矿产资源的现象仍存在,要继续深入宣传贯彻《矿产资源法》。  相似文献   

矿物包裹体中水溶气体成分的物理化学参数图解   总被引：8，自引：3，他引：8  

徐文xin 《矿产与地质》1991,5(3):200-206

本文计算出1m～3mNaCl体系.温度为100～500℃条件下CO_2、CH_4、H_2、CO、N_2、H_2S和SO_2亨利常数,以及上述成分在100～350℃时的分配系数和气、液平衡常数.并设计出矿物包裹体中水溶气体的lgfo_2—T、lgf_(co)-T、lgf_(co)-T和lgf_(co)-pH等物理化学参数图,解析了江西茅坪锡矿床中石英和锡石的矿物包裹体形成的物理化学条件.  相似文献   

Aggregate resources: Production and environmental constraints     

R. Poulin  R. C. Pakalnis  K. Sinding 《Environmental Geology》1994,23(3):221-227

Aggregates are produced from sand and gravel deposits or from bedrock sources. Production sites are numerous to minimize transport and are more and more in a competing land use position. Urbanization, while creating a market, also sterilizes deposits and pressures producers to relocate further from populated areas. Regulating and permitting quarries is an issue in regions with growing populations. This regulatory environment may cause exploitation schemes to evolve towards greater recycling, importing, and marine production, for example. These changes may be entirely attributable to increased environmental constraints on producing operations and not on conventional mining constraints such as overburden, ore grade, and costs of operation.  相似文献