东天山雅满苏铁矿床夕卡岩成因及矿床成因类型

新疆东天山雅满苏铁矿床是该区乃至我国产于海相火山岩中的典型铁矿床,其矿床成因类型长期以来一直有海相火山岩型和矽卡岩型之争,争论的焦点是该矿床中矽卡岩的成因,影响了关键控矿要素的确定和找矿标志的建立.为了探讨矽卡岩的成因,本文测定了穿插铁矿体和矽卡岩的辉绿岩脉的锆石SHRIMP U-Pb年龄,采用XRF方法测定了雅满苏铁矿区火山岩、火山沉积岩和矽卡岩的主量元素含量,采用电子探针方法分析了该矿床不同产态不同期次矽卡岩中石榴石的矿物组成.测得辉绿岩脉锆石年龄为335Ma,将雅满苏矿区铁矿化和矽卡岩的形成时代限定于335Ma之前,表明矿化蚀变与火山岩同期,是雅满苏组火山岩喷发期热液交代作用的产物.岩矿鉴定也显示热液改造首先形成葡萄石,进而由于流体中铁质的加入形成石榴石.两期石榴石的矿物化学特征表明早期形成的石榴石富铁;晚期形成的石榴石铁质含量低,并有磁铁矿和黄铁矿等金属矿物与其共生.由于该矽卡岩的形成与火成岩体接触带的交代作用没有明显成因联系,因此笔者认为该矿床中的矽卡岩属广义矽卡岩,矿床成因类型归为海相火山岩型铁矿床更合理.     

冀北与角闪石岩相关铁钛磷灰岩的特征及成因-磷灰石矿物化学的证据

铁钛磷灰岩在超基性岩中很少发育,笔者野外工作发现冀北铁马哈叭沁超基性岩杂岩体的角闪石岩中发育少量团块状铁钛磷灰岩。本研究选择岩浆演化不同阶段的辉石角闪石岩、角闪石岩和铁钛磷灰岩中的磷灰石进行了电子探针和LA-ICP-MS激光探针分析,对比分析了磷灰石矿物主微量元素特征。不同岩石类型中磷灰石微量元素蛛网图形态十分相似,但铁钛磷灰岩中磷灰石的F、U、Th、Sr、∑REE含量明显更高,连续变化的趋势与岩体岩相序列相符,表明在岩浆演化的晚期阶段,随着分异程度的增强,角闪石岩母岩浆中的Fe-Ti-P组分逐渐富集并达到饱和,从而在角闪石岩中发育团块状的铁钛磷灰岩。     

Discrete element method analysis of non‐coaxial flow under rotational shear

This study focuses on non‐coaxial flow behavior of cohesionless soil undergoing cyclic rotational shear, with a special interest in the effects of particle‐scale characteristics. To this end, we perform a series of 2D discrete element simulations with various particle shapes, inter‐particle coefficient of friction, initial density, and stress ratios. The validity and efficacy of the numerical model is established by systematically comparing numerical simulation results with existing laboratory testing results. Such comparison shows that the numerical simulations are capable of capturing mechanical behavior observed in laboratory testing under rotational shear. We further demonstrate and quantify a strong yet simple relationship between the deviatoric part of the normalized strain increment and the non‐coaxial angle, denoted by and ψ, respectively. This quantitative correlation between ψ and is independent of applied stress ratio, initial and current void ratio, and the number of cycles applied, but dependent on the principal stress orientation and particle‐scale characteristics. At the same , specimens with higher inter‐particle friction angle or smaller particle aspect ratio show greater non‐coaxial angles. A simple model is able to fit this ψ‐ relationship well, which provides a useful relationship that can be exploited in developing constitutive models for rotational shearing. Copyright © 2014 John Wiley & Sons, Ltd.     

Introduction to the special issue on scale and spatial analytics

Journal of Geographical Systems -     

越南阮朝顺化皇城嵌瓷装饰景观特征及影响机理分析

采用实地考查、信息采集、测绘数据、文献整理等研究方法,以越南阮朝顺化皇城修复的主要宫殿为例,从文化地理学和设计学的角度提取识别越南顺化皇城空间格局、装饰题材、色彩配置的景观特征,揭示其与中国岭南嵌瓷装饰的内在关系及影响机理。结果表明：顺化皇城嵌瓷在岭南建筑装饰中融入本土文化,之所以形成越南官署嵌瓷样式,是因为相似的自然地理环境、中国建筑陶瓷的区际辐射和阮朝统治阶层的青睐等因素共同作用的结果,嵌瓷装饰的文化表征集巧丽繁缛于一体的,彰显出宗法礼教与国家意志的皇权空间特质,成为东南亚王宫建筑景观的典范。为推进“一带一路”的建设,活化中外文明交流互鉴的文化遗产提供参考。     

川中雷口坡组膏盐岩成因及对储层的影响

通过岩心观察、薄片鉴定、成岩孔隙演化与埋藏史关系研究等手段,分析了川中雷口坡组膏盐岩微相的成因及其演化,并从沉积相、成岩过程、构造作用三个方面论述了膏盐岩对川中雷口坡组储层的控制与影响。研究表明,川中雷口坡组膏盐岩形成于受限陆表海的潮坪环境,其微相分为潮上带的膏盐池、潮间带的膏盐湖和局限潮下带的膏盐盆;其成因可分为潮上带浓卤水在低洼处汇聚成因或潮间潮下带表层浓卤水下沉置换成因;其分布与海平面升降导致的膏盐岩沉积中心迁移有关,同时与点滩的分布也有一定联系。膏盐岩的形成以及同生—准同生期溶蚀、表生期溶蚀垮塌、中—深埋藏期的硫酸盐热化学还原反应产生的埋藏溶蚀等作用对川中雷口坡组中上部储层的形成控制有重要贡献。此外,膏盐岩的底辟作用和构造运动产生的裂缝、断层,对烃源的运移、气藏的重新分布起着一定的促进作用。     

珲春地区地下水现状及水资源评价与分析

本文通过对珲春地区水文地质条件进行分析,计算出珲春地区的水文地质参数和地下水资源量、珲春市河谷盆地地下水天然水资源量和珲春市山丘区多年平均地下水天然水资源量计算。对珲春地区地下水水资源量和地下水水质进行评价和分析,为今后经济社会与自然的和谐发展、合理开发利用水资源提供了科学依据。     

新疆侏罗纪古构造及其对聚煤盆地的控制

古构造是控制聚煤盆地形成与演化的首要地质因素。新疆赋煤区是由前寒武纪形成的大陆古板块、微型陆块与古生代形成的造山带镶嵌而成的复合大陆块体。早-中侏罗世,区域挤压应力松弛甚至出现区域拉张应力,盆-山耦合型前陆-克拉通盆地成为新疆早-中侏罗世聚煤盆地的主体;基底性质不同的两个构造单元之间及造山带内部,形成带状拉张断陷;在某些早期弧后盆地和残留海盆分布的地区,发生继承性沉降,成为陆相聚煤盆地。在具有前寒武纪基底的前陆-克拉通盆地和继承性盆地中,聚煤作用最为强盛;发育在古生代造山带之上的伸展断陷型山间盆地,聚煤强度的横向变化较大。     

Adsorption of roxarsone by iron (hydr)oxide-modified multiwalled carbon nanotubes from aqueous solution and its mechanisms

The adsorption of roxarsone by iron (hydr)oxide-modified multiwalled carbon nanotubes (MWCNTs) from aqueous solution and its mechanism were investigated. The amount of roxarsone adsorbed by modified MWCNTs is higher than MWCNTs at the same condition. The results show that the sorption isotherms are nonlinear, and can be well fitted according to the Freundlich and Polanyi–Manes models. The adsorption kinetics could be well described by pseudo-second-order model. Thermodynamic analysis shows that the adsorption of roxarsone on the adsorbents is an exothermic and spontaneous process. Desorption process had no obvious desorption hysteresis phenomenon. The FT-IR and XPS analysis confirmed the loading of iron ions on the MWCNTs, and revealed the involvement of carboxyl groups and iron ions on the adsorption of roxarsone.     

Tree ring based Pb and Zn contamination history reconstruction in East China: a case study of Kalopanax septemlobus

To reconstruct trace metal contamination history in the Yangtze River Delta region, annual growth rings of native hardwood species, Kalopanax septemlobus, were studied as the potential archive of the past Pb and Zn pollution events. Wide distribution of K. septemlobus trees in the study area and clear annual tree rings are advantages of this potential geochemical archive. In this research, tree ring increments for 48 years, from 1960 to 2007, were analyzed for Pb and Zn concentrations. Trees were sampled in two sites, Xiaoyingpan, a contaminated area around a mine (Pb, Zn, Ag) in the Yangtze River Delta region, and a reference site 19 km away. The results show that: (1) distinct Pb and Zn concentrations increasing from 1960 to 1974 in the polluted site were coincident with increasing historical open mining activities; (2) from 1974 to 1986, Pb and Zn concentrations dramatically decreased during a conversion from above-ground exploitation to below-ground extraction; and (3) after 1992, the concentration of Zn decreased gradually, but Pb concentrations initially increased with automobile traffic from 1986 to 2004, then decreased when the number of automobiles was controlled from 2004 to 2007. In particular, Pb and Zn concentrations in tree rings had no effect on K. septemlobus growth. Pb and Zn concentrations in tree rings were linearly related with those in soils. Growth rings of K. septemlobus around the Pb, Zn, Ag mine accurately recorded historical changes in Pb and Zn deposition.