Anomaly Models of Spatial Structures for Copper-Molybdenum Ore Deposits and their Application     

MA Shengming  ZHU Lixin  LIU Chongmin  XI Mingjie  TANG Shixin 《《地质学报》英文版》2013,87(3):843-857

This paper discusses the enrichment and depletion regularities for porphyry copper-molybdenum ore deposits in different regions and varied deposit genetic types in the same area, taking three porphyry copper-molybdenum ore deposits (i.e., the Chengmenshan in Jiangxi, Wunugetushan in Inner Mongolia, Baishantang in Gansu) and two copper deposits in Gansu Province (the Huitongshan skarn deposit and Gongpoquan composite deposit) as case studies. The results show that porphyry Cu-Mo deposits or skarn copper deposits include both enrichment of the ore-forming elements and associated elements, and depletion of some lithophile dispersed elements, rare earth elements (REE) and some major elements. And the depleted elements vary with deposits, having generality and their own features. On a deposit scale, the positive anomalies of enriched elements and negative anomalies of depleted elements follow in a sequence to comprise regular anomaly models of spatial structures. The exploration in the Tongchang deposit in Jiangxi and Huitongshan deposit in Gansu suggests that anomaly models play a key role in the identification of mineral occurrences and deposits compared to one single enriched element anomaly. And the anomaly models exert a critical effect on the optimization of prospecting targets and their potential evaluation.  相似文献   

Temporal trends and spatial characteristics of drought and rainfall in arid and semiarid regions of Iran   总被引：5，自引：0，他引：5  

Hossein Tabari  Hirad Abghari  P. Hosseinzadeh Talaee 《水文研究》2012,26(22):3351-3361

Drought, a normal recurrent event in arid and semiarid lands such as Iran, is typically of a temporary nature usually leaving little permanent aftermath. In the current study, the rainfall and drought severity time series were analyzed at 10 stations in the eastern half of Iran for the period 1966–2005. The drought severity was computed using the Standardized Precipitation Index (SPI) for a 12‐month timescale. The trend analyses of the data were also performed using the Kendall and Spearman tests. The results of this study showed that the rainfall and drought severity data had high variations to average values in the study period, and these variations increased with increasing aridity towards the south of the study area. The negative serial correlations found in the seasonal and annual rainfall time series were mostly insignificant. The trend tests detected a significant decreasing trend in the spring rainfall series of Birjand station at the rate of 8.56 mm per season per decade and a significant increasing trend in the summer rainfall series of Torbateheydarieh station at the rate of 0.14 mm per season per decade, whereas the rest of the trends were insignificant. Furthermore, the 12‐month values of the standardized precipitation index decreased at all the stations except Zabol during the past four decades. During the study period, all of the stations experienced at least one extreme drought which mainly occurred in the winter season. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

中国海陆1∶500万地质地球物理系列图与数据库研制     

张训华  王忠蕾  温珍河  杨金玉  郭兴伟  侯方辉 《地球信息科学学报》2013,15(1):115-122

60年来,利用我国各种地质地球物理数据,结合野外考察,运用块体构造学说编制了中国海陆1∶500万地质地球物理系列图。其从理论基础、方法技术上,实现中国海陆地质地球物理数据的融合;系统地反映出我国海陆基础地质调查与研究现状及大地构造格架;同时展示古生代以来中国海陆各块体的发育、运移、拼接和联合大陆的形成过程,以及印支运动后中国大陆由"东高西低"转为目前"西高东低"的演化规律。另外,通过系列图件的编制与建库,为我国矿产资源勘探及资源环境效应研究提供了基础图件数据。  相似文献   

A comparative study of the sensitivity of F v/F m to phosphorus limitation on four marine algae     

QI Hongju  WANG Jiangtao  WANG Zhaoyu 《中国海洋大学学报(英文版)》2013,12(1):77-84

We studied the effects of nitrogen (N) and phosphorus (P) supply on Fv/Fm (maximal quantum yield of photosystem II) in the algae Chaetoceros debilis, Dicrateria inornata, Platymonas subcordiformis and Heterosigma akashiwo to determine the sensitivity of Fv/Fm to P-limitation of the four species. Obvious decrease of Fv/Fm value was monitored in periods of P-depletion, the decrease showing different magnitudes among algal species. A more clear decrease of Fv/Fm in Platymonas subcordiformis and Het-erosigma akashiwo was observed, compared with that in Chaetoceros debilis and Dicrateria inornata. After the resupply of P, the index Fv/Fm of the four species all recovered quickly in 24 h. Cell division was maintained and chlorophyll content continued to increase until the end of the experiment in Platymonas subcordiformis and Heterosigma akashiwo, while in Chaetoceros debilis and Dicrateria inornata, the division stopped in the later period when the growth of organisms came into the stationary phase. The most obvious respond of chlorophyll content to P-additions was observed in Het-erosigma akashiwo culture in 24 h. The sensitivity of Fv/Fm to nutrient limitations is different among algal species, and much should be done to improve the application of this index.  相似文献   

A Comparative Study of the Sensitivity of Fv/Fm to Phosphorus Limitation on Four Marine Algae     

QI Hongju  WANG Jiangtao  WANG Zhaoyu 《青岛海洋大学学报(英文版)》2013,(1):77-84

  相似文献   

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闫志闯  张传定  杜兰  蒲亭汀  李婧 《大地测量与地球动力学》2013,33(2):96-100

??????????????й?????????????????????????VS2010????????PPL??????м??????????????C++11?????C++0x???±???????????????????????????ж????????????з?????????????????????????????????????????????????????????????????????????Ч???  相似文献   

On Correlational Properties for Volcanic Earthquakes Associated with Asamayama (Japan), 1983–2005     

Richard A. Reyment 《Natural Resources Research》2008,17(3):135-143

To a first approximation, earthquakes directly associated with volcanic activity may be studied as point-stochastic processes. The earthquakes associated with B-type (movements located at 1 km or shallower) eruptive activity in the caldera of Asamayama differ in correlational properties from concurrent deep-seated seismic activity (A-type, located deeper than approximately 1 km). A-type activity occurs either in the form of independently distributed intervals between events or as dependently distributed intervals which are most appropriately analysed in contiguous sub-samples (“windows”). The cross correlations between the magnitudes of A-type earthquakes and depth of events for three periods from 1983 to 2005 may be of significance for interpreting aspects of the volcanic history of Asamayama. The lag-1 serial correlation coefficient for the A-type sequence from 1983 to 1990 is not significantly different from zero. In the case of the sets for 1991–2002 and 2003–2005, the coefficients are small but not zero. The difference is in part, at least, probably due to the well-known confounding effect of trending as opposed to true serial correlation between successive events. The serial correlation coefficient for the B-type crater sequence is not significant. The novel aspect of the present study concerns the relationship between depth of A-type earth movements and magnitude of associated shocks.  相似文献   

一种新的时间序列特征指标:简单线性回归系数SLC     

周科松  吴健平  张胜茂  徐展 《地理与地理信息科学》2008,24(1):14-16

长时间序列遥感图像中含有大量的噪声和坏数据,给分类带来困难。该文提出一种新的时间序列特征指标:像元时间序列的简单线性回归系数(SLC),用来提高分类精度。为证明其有效性,设计出一套模拟实验。结果表明:SLC具有较强的抗噪声、抗坏数据能力,有利于提高分类精度,特别是对于植被指数时间序列遥感图像。  相似文献   

轮南低凸起气洗作用响应及定量评价   总被引：2，自引：0，他引：2  

吴楠  蔡忠贤  杨海军  陈建渝  刘显凤  顾乔元 《地球科学》2009,34(3):486-492

自喜山期, 过量干气自东向西对轮南低凸起原始油藏的大规模侵入、冲刷, 诱发本区持续性气洗分馏作用的发生.在各组分气液溶解平衡的格架下, 气洗作用将导致残余油中正构烷烃的大量损失以及次生凝析气藏的形成.地球化学研究表明, 残余油与凝析油中轻烃组分(C₆-C₈) 的变化趋势具有典型的气洗分馏特征.同时, 基于气洗作用模型, 通过对各层系原油正构烷烃相对蒸发量(Q) 的计算, 定量描述了轮南地区气洗作用的强度.计算结果显示, 奥陶系的油气藏曾遭受强烈的气洗作用, 原油中正构烷烃的相对蒸发量由东向西表现出依次递减的特征.其中, 轮古东地区Q值高达97%;位于轮南低凸起中部的轮古2井以及轮古18井地区, 正构烷烃相对蒸发量较小(Q=20%~76%); 而在更加靠近西部的轮古17及轮古100井, 其原油中正构烷烃分布正常(Q=0), 并未发生气洗分馏作用.另一方面, 石炭系以及三叠系的油气藏均表现出未遭受气洗作用的特征, 证实了喜山期大量干气的优势运移通道被限制于海西早期运动所形成的奥陶系岩溶缝洞体系中的事实.因此, 奥陶系, 尤其是位于临近气源区的轮古东地区, 是轮南地区气藏的有利靶区.   相似文献   

Three-dimensional semi-analytical solution to groundwater flow in confined and unconfined wedge-shaped aquifers     

Mohammad Mahdi Sedghi  Nozar Samani  Brent Sleep 《Advances in water resources》2009

The Laplace domain solutions have been obtained for three-dimensional groundwater flow to a well in confined and unconfined wedge-shaped aquifers. The solutions take into account partial penetration effects, instantaneous drainage or delayed yield, vertical anisotropy and the water table boundary condition. As a basis, the Laplace domain solutions for drawdown created by a point source in uniform, anisotropic confined and unconfined wedge-shaped aquifers are first derived. Then, by the principle of superposition the point source solutions are extended to the cases of partially and fully penetrating wells. Unlike the previous solution for the confined aquifer that contains improper integrals arising from the Hankel transform [Yeh HD, Chang YC. New analytical solutions for groundwater flow in wedge-shaped aquifers with various topographic boundary conditions. Adv Water Resour 2006;26:471–80], numerical evaluation of our solution is relatively easy using well known numerical Laplace inversion methods. The effects of wedge angle, pumping well location and observation point location on drawdown and the effects of partial penetration, screen location and delay index on the wedge boundary hydraulic gradient in unconfined aquifers have also been investigated. The results are presented in the form of dimensionless drawdown-time and boundary gradient-time type curves. The curves are useful for parameter identification, calculation of stream depletion rates and the assessment of water budgets in river basins.  相似文献