滇西北烂泥塘斑岩铜矿床原生晕异常结构研究

烂泥塘矿床是云南香格里拉地区典型的斑岩型铜矿床,主矿体产于在地表以下300～500米,地表矿化带仅见脉状铜矿体和铜矿化体.为研究云南香格里拉烂泥塘斑岩铜矿床的原生晕异常结构,本文以异常结构模式理论和方法为基础,对矿床地表和坑道岩矿石样品开展了元素组合、异常特征和水平分带规律研究.结果表明,烂泥塘铜矿床地球化学系统的结构...     

Geochemistry,petrogenesis and tectonic setting of the peraluminous granites in the nacheng gold deposit,Yongning, Guangdong北大核心

The Nacheng granite locates in the Yong ning area, Guangdong Province. This paper studied petrographical and chronological characteristics of this granite as well as its petrogenesis and geological significance. The Nacheng granite mainly consists of quartz (40%-50%), orthoclase (25%-30%), palgioxlase (15%-20%) with minor accessory minerals of quartz apatite and magnetite. Geochemical analyses show that the manziying granite has high content of SiO2 (75. 56%) , K2O (4.72%), Al2O3 (13. 34%) and total alkali (Na2O+K2O=7. 49%), but relatively low MgO (0. 04%-1. 29%) and CaO (0. 39%-2. 21%). The ratios of K2O/Na 2O are generally higher than 1. The Rittmann indexes are between 1-2. 43, belonging to the high-K calc-alkaline series. The values of A/CNK vary from 1. 12 to 1. 32 with an average of 1. 10, showing the characteristics of peraluminous S type granites. Trace element analyses show that the Nacheng granite has relatively high REE content of 82. 6 × 10-6 225. 68 × 10-1, and displays right-inclined V-shape REE patterns with relatively high fractionations of LREE and HREE[(La/Yb)N = 1. 51-9. 66] and pronounced negative Eu anomalies (δEu = 0. 31-0. 74) in the chondrite-normalized REE diagrams, suggesting a typical crust-derived grandite. The magmas may be divided into two types: "low-temperature" type from mudstones and "high-temperature" type from sandstones. The Nacheng granites were formed from the post-orogenic tectonic setting.     

徐家围子断陷深层火石岭组致密火山岩储层地应力分布规律研究

徐家围子断陷位于松辽盆地北部,其深层中生代火石岭组为致密火山岩气藏,天然裂缝发育,地应力分布非均质性强。结合诱导裂缝法与井径崩落法进行单井现今地应力方向分析,利用声波测井法计算现今地应力大小的纵向分布。依据火石岭组构造顶底面图、火山岩相组及断层分布特征建立非均质三维地质模型;在动、静态岩石物理参数拟合校正的基础上,结合实验测试及已有研究成果,确定不同岩相组和断层岩石物理参数,建立三维力学模型;利用Ansys有限元数值模拟软件建立火石岭组三维数学模型并进行相关运算获得三维现今地应力分布模型。计算结果表明在火石岭组地层中,水平最大主应力方向主要为东西向,应力值范围在86~110 MPa;水平最小主应力方向主要为南北向,应力值范围在67~84 MPa。分析模拟结果可知火山岩相、断层和构造起伏三者对火石岭组现今地应力分布影响较大。其中水平主应力的方向主要受断层和近火山口相分布的影响,而水平主应力的大小则是受三者综合作用。在构造低部位,近火山口相组发育处,断层上盘及断层端部皆为主应力的集中区域。依据现今地应力研究成果可为徐家围子断陷下一步开发井网部署、压裂改造方案和水平井的设计以及注水管理提供重要指导。      

天山乌苏段火山泥元素组成及含量分析

采用能量色散型X射线荧光光谱分析（EDXRF）对新疆乌苏天山泥火山土壤样品的元素含量进行了测定。采用单指标评价指数法和内梅罗综合指数法,对新疆天山乌苏段火山泥中的重金属的种类和含量进行了研究,结果显示：Cd、As、Cu元素的含量达到土壤环境质量评价的二级标准,Hg、Pb、Cr、Zn、Ni元素的含量达到土壤环境质量评价的一级标准,乌苏天山火山泥综合评价达到二级标准。将火山泥的元素含量与新疆地区不同土质的土壤元素含量进行比较,与干旱区不同省份的土壤元素含量进行比较,分析了火山泥元素组成及含量的成因。     

Drought characteristics of Henan province in 1961-2013 based on Standardized Precipitation Evapotranspiration Index

Drought is one of the most complex natural hazards affecting agriculture, water resources, natural ecosystems, and society. The negative societal consequences of drought include severe economic losses, famine, epidemics, and land degradation. However, few studies have analyzed the complexity of drought characteristics, both at multiple time scales and with variations in evapotranspiration. In this study, drought occurrences were quantified using a new drought index, the Standardized Precipitation Evapotranspiration Index (SPEI), based on observed data of monthly mean temperature and precipitation from 1961 to 2013 in Henan province, central China. Based on the SPEI values of each weather station in the study, the frequency and severity of meteorological droughts were computed, and the monthly, seasonal, and annual drought frequency and intensity over a 53-year period were analyzed. The spatial and temporal evolution, intensity, and the primary causes of drought occurrence in Henan were revealed. The results showed that the SPEI values effectively reflected the spatial and temporal pattern of drought occurrence. As the time scale decreased, the amplitude of the SPEI increased and droughts became more frequent. Since 1961, drought has occurred at the annual, seasonal, and monthly scales, and the occurrence of drought has increased. However, regional distribution has been uneven. The highest drought frequency, 35%, was observed in the Zhoukou region, while the lowest value, ~26%, was measured in central and western Henan. The most severe droughts occurred in the spring and summer, followed by autumn. Annually, wide-ranging droughts occurred in 1966–1968, 1998–2000, and 2011–2013. The drought intensity showed higher values in north and west Henan, and lower values in its east and south. The maximum drought intensity value was recorded in Anyang, and the minimum occurred in Zhumadian, at 22.18% and 16.60%, respectively. The factors with the greatest influence on drought occurrence are increasing temperatures, the Eurasian atmospheric circulation patterns, and the El Niño effect.     

山东省灵山岛下白垩统青山群火山地震软沉积物变形构造特征及成因机制*

近年来,针对山东省灵山岛地区软沉积物变形构造的研究呈现热潮,但研究层位主要集中于下白垩统莱阳群的浊积岩,对下白垩统青山群未见详述。利用野外露头与镜下薄片资料,详细描述了灵山岛地区下白垩统青山群的岩性特征、岩相组合、软沉积物变形构造类型与特征,指出研究区青山群软沉积物变形构造主要宿主岩层为陆相扇三角洲沉积,其沉积水体逐渐变浅,并伴随多次火山爆发。软沉积物变形构造类型主要有负载构造、球—枕构造、泄水构造、挤入构造、水塑性褶皱、塑性砂岩团块包卷构造、火山地震落石构造和“V”型地裂缝等,形成原因主要为火山爆发引起的古火山地震作用,成因机制主要分为地震波、火山碎屑物重力及惯性作用与瞬时差异气压效应3种,这与莱阳群浊积岩层位的软沉积物变形构造主要为滑塌与构造古地震机制不同。通过分析火山碎屑流堆积层位与软沉积物变形构造发育层位的关系,建立了青山群软沉积物变形构造的分布模式,即随着与火山口距离的变化,近源易见的脆性变形逐渐消失,中源以液化软沉积物变形与塑性变形为主体,远源呈现弱的液化软沉积物变形,且软沉积物变形构造的规模与距离呈负相关。     

海相火山岩区地质填图方法——以北祁连山东段白银矿田古火山机构厘定为例

20世纪90年代以来,火山机构控矿理论在海相火山岩区块状硫化物矿床研究中得到了越来越多的关注,基于该理论的指导,在北祁连山东段的白银矿田取得了找矿突破性进展。其间,详细的海相火山岩相地质填图工作为白银矿田火山机构与成矿联系的研究及找矿突破奠定了坚实的基础。反映出在海相火山岩区推行合理可行的火山岩相地质填图方法至关重要。以白银矿田海相火山岩区为例,首先,对该区大比例尺火山岩相填图及古火山机构厘定成果进行介绍;其次,通过分析、借鉴此成功案例,总结海相火山岩区填图内容和技术方法;最后,阐述应用该方法在北祁连山中段祁连县一带海相火山岩区进行大比例尺填图的成功尝试。     

宁芜火山岩盆地及邻区上地壳电性结构研究

为了较全面、客观地认识宁芜矿集区上地壳电性结构,研究"玢岩铁矿"成矿规律与深部地球物理、地质结构的对应关系,为探索深部"第二找矿空间"提供物性参数,我们完成了6条宽频大地电磁测深剖面.通过分析各剖面电性成像结果,讨论了"长江断裂带"与矿集区成矿的关系,并且认为围岩、岩浆及其上侵通道是区内矿床的控矿因素.此外,结合姑山铁矿床的位置以及铁矿床成矿规律判断宁芜火山岩盆地南部低阻条带为矿集区姑山火山-岩浆旋回的岩浆(导矿)通道,而盆地东部邻区的倾斜"叠瓦状"电性特征说明该区在经历了印支期褶皱构造运动后发育了逆冲推覆构造.     

petrological and geochemical characteristics of quarternary volcanic rocks in haixing area,eastern north china

Field investigation and lab analysis on samples were carried out for Quaternary volcanoes, including Xiaoshan volcano, Dashan volcano and Bianzhuang hidden volcano, in Haixing area, east of North China. Results show that Xiaoshan volcano with the eruptive material of volcanic scoria, crystal fragments and volcanic ash is a maar volcano, the eruptive pattern is pheatomagmatic eruption, and the influence scope is near the crater. Dashan volcano exploded in the early stage, and then the magma intruded, forming the volcanic neck. The eruption strength and scale are limited, and the eruptive materials are scoria, volcanic agglomerate and dense lava neck. The volcanic rocks in Bianzhuang are porosity and dense volcanic rocks and volcanic breccia, reflecting the pattern of weak explosive eruption and lava flow, and the K-Ar age dating on volcanic rocks indicates that the eruption happened in early Pleistocene. Xiaoshan volcanic scoria and Bianzhuang hidden volcanic rocks are mainly basaltic, Dashan volcanic rocks with lower SiO₂ content are nephelinite in composition. Their oxide contents have no linear relationship, indicating that there is no magma evolution relationship between these magmas from the three places. Three volcanic rocks all have enrichment of light rare earth. The Bianzhuang volcanic rocks are rich in large ion lithophile elements, and have no high field strength elements Zr and Hf, Ti losses. The volcanic materials from Xiaoshan and Dashan are intensively rich in Th, U, Nb and Ta, and significantly poor in K and Ti. Although the magmas from these three places in Haixing area may all come from asthenosphere, the volcanic materials have different petrological and geochemical features, and relatively independent volcanic structures, therefore, they experienced different magma processes.     

安徽省区域旅游经济发展的时空格局演变

分析了安徽省区域旅游发展模式,以各市2001-2013年的旅游总收入、入境旅游收入和国内旅游收入为基础数据,从时间变化和空间演变两个方面分析安徽省区域旅游经济差异。结果表明：① 安徽省区域旅游产业的发展经历了点状模式、放射状模式、双核联动发展模式演化阶段;② 安徽省旅游经济发展不均衡,不同地市间旅游经济发展水平差异很大,国际旅游空间差异更是大于国内旅游,安徽省区域旅游经济空间差异的“南强北弱”基本格局没有发生根本的改变;③ 安徽省各地市旅游经济发展具有明显的首位分布特征,特别是入境旅游呈现出典型的首位分布,其总收入、国内旅游首位度大致经历了先降后升的演变,入境旅游首位度基本上呈现下降趋势,首位城市主要在黄山市和合肥市之间展开竞争;④ 旅游产业要素从时间角度看,旅游景区、旅行社和星级饭店增长迅速,从空间角度来看,旅游景区主要集中在黄山、安庆、六安等地,旅行社和星级饭店主要集中在合肥、黄山等地;⑤ 影响安徽省区域旅游时空格局演变的主要因素有旅游资源禀赋、旅游政策、交通网络、旅游市场需求、区域产业发展战略调整及区域经济发展水平等。