墨西哥西马德雷山脉中—新生代构造、岩浆演化及成矿特征   总被引：1，自引：0，他引：1  

姚春彦  姚仲友  李汉武  郭维民  刘君安 《地质通报》2017,36(12):2124-2133

墨西哥西马德雷山脉是白垩纪—新生代岩浆活动和构造运动形成的。中新生代岩浆活动可以分为5个主要阶段:侏罗纪—早白垩世、晚白垩世—古新世、始新世—渐新世、中新世早期和中新世中期—现代。这些岩浆活动和构造运动与法拉隆(Farallon)板块向北美大陆俯冲和加利福尼亚湾打开相关。墨西哥中新生代的成矿作用与东太平洋板块边缘连续的俯冲过程密切相关,矿床类型多样,包括VMS(与火山相关的块状硫化物)型、斑岩型、IOCG(铁氧化物铜金)型、矽卡岩型等。  相似文献   

藏南色如朗金红石矿床地质特征及控矿条件   总被引：1，自引：1，他引：0  

高忠维  解超明  任云生  刘一鸣  罗安波 《地质通报》2017,36(11):2091-2097

藏南色如朗金红石矿床位于米拉山口断裂带东段北缘,矿床的赋矿岩石主要为绿片岩。由北向南圈定了3个矿体,矿体沿北东方向延伸,呈层状、似层状产出。矿石矿物以金红石为主,其他金属矿物有磁铁矿、赤铁矿、黄铁矿、黄铜矿、磁黄铁矿等。金红石主要为红褐色,少数为暗红褐色,呈自形-半自形柱状和他形粒状,粒径多为0.01~0.2mm,大者可达1~2mm。该矿床的形成主要受地层和变质作用控制,后期构造对矿床形态有一定的破坏作用。通过与中国典型金红石矿床地质特征对比,初步认为色如朗金红石矿床的成因类型为中低压变质型。  相似文献   

中亚造山带东部岩浆热液矿床时空分布特征及其构造背景   总被引：1，自引：0，他引：1  

吕斌  王涛  童英  张磊  杨奇荻  张建军 《吉林大学学报(地球科学版)》2017,47(2)

中亚造山带东部是古亚洲洋构造域、鄂霍茨克洋构造域和古太平洋构造域复合叠加区域,矿产资源丰富。本文收集2000—2014年公开发表文献中岩浆热液矿床约1 200个同位素年龄数据,整理出201个较为可靠的年龄数据,通过数字化编图,揭示成矿的时空分布特征及形成背景。结果显示:中亚造山带东部成矿作用始于寒武纪,出现6个重要成矿期:510~473、373~330、320~253、250~210、210~167、155~100 Ma。510~473 Ma(峰值507 Ma),矿床主要分布在大兴安岭—小兴安岭—张广才岭和北山地区,零星发育热液脉型和斑岩型铁铜金钨矿床,与古亚洲洋开始俯冲及微陆块碰撞拼合有关。373~330 Ma(峰值372Ma),矿床主要分布在南蒙古奥尤陶勒盖地区,发育超大型斑岩型铜金矿床,形成于古亚洲洋俯冲环境。320~253 Ma,矿床主要分布在大兴安岭南段,发育少量斑岩型铜矿床和造山型金矿床;其中,298 Ma在大兴安岭南段首次出现以钼为主的斑岩型矿床,指示该区板块俯冲增生向拼贴转变逐渐过渡。250~210 Ma(峰值244 Ma),在蒙古—鄂霍茨克造山带东侧额尔古纳—中蒙古地块主要形成斑岩型铜矿床,可能与蒙古—鄂霍茨克洋俯冲有关;以东地区,主要在大兴安岭南段和辽远地块形成斑岩型钼矿床,在张广才岭发育岩浆熔离型铜镍矿床,反映了古亚洲洋闭合后伸展环境。210~167 Ma(峰值170 Ma),在蒙古—鄂霍茨克造山带西侧乌兰巴托西北部发育造山型-斑岩型金矿床,其东侧额尔古纳地区形成斑岩型铜钼矿床,可能与蒙古—鄂霍茨克洋俯冲碰撞有关;在吉黑东部—张广才岭—小兴安岭—大兴安岭,发育斑岩型钼铜矿床和矽卡岩型铅锌钨金矿床组合,可能属于古太平洋板块向西俯冲成矿体系。155~100 Ma(峰值136 Ma),中亚造山带东部整体处于伸展环境;其中,155~120 Ma在额尔古纳地区主要发育浅成低温热液型银铅锌矿床和造山型金矿床,大兴安岭北段发育斑岩型钼矿床,可能反映了额尔古纳地区和大兴安岭北段受蒙古—鄂霍茨克洋碰撞后伸展环境控制,而在吉黑东部形成浅成低温热液型金矿床,大兴安岭南段发育热液脉型-矽卡岩型锡矿床,可能受古太平洋板块向北俯冲弧后伸展的控制;120~100 Ma沿着华北克拉通和佳蒙陆块边缘发育浅成低温热液型-斑岩型金钼矿床。本研究综合岩浆热液矿床时空分布和矿床类型,进一步揭示了古亚洲洋构造域控制中亚造山带东部古生代成矿作用持续到晚二叠世(到早三叠世),并在晚三叠世叠加古太平洋构造域成矿体系,而额尔古纳—中蒙古地块成矿作用在三叠纪开始主要受蒙古—鄂霍茨克洋构造域限定,并持续到早白垩世早期。  相似文献   

Analysis on hydrochemical characteristics of groundwater in strongly exploited area in Hutuo River Plain     

TIAN Xia  FEI Yu-hong  ZHANG Zhao-ji  LI Ya-song  DUN Yu  GUO Chun-yan 《地下水科学与工程》2017,5(2):130-139

The Hutuo River alluvial-proluvial fan is located in North China Plain, and groundwater is the main source of water supply for agriculture and domestic water. Shijiazhuang depression funnels due to the long-term excessive exploitation are the bottleneck of the regional economic development. Analyzing the chemical characteristics of groundwater under the condition of strong human activities, can provide a scientific basis for further study of strong groundwater mining area environmental change. 143 groups of shallow groundwater samples are collected during the period of 2007-2008. In this paper, the hydrochemical characteristics of groundwater in the Hutuo River Plain area are analyzed systematically, using hydrogeochemical theory, combined with statistical methods and hydrochemical methods. Results are shown as follows: HCO_3~- and Ca~(2+) are major anion and cation. The variation coefficients of K~+, Ca~(2+), Mg~(2+) and HCO_3~- between 0.25 and 0.52, which means small and stable relatively. The variation coefficient of are Na~+, NO_3~-, Cl-, SO2-4 were large(0.89-1.01). They are sensitive and vulnerable to environmental change affect. Due to the impact of human activities, from the top to the edge of the alluvial-proluvial fan, the hydrochemical types of groundwater change from single to multiple, followed by HCO_3~-Ca·Mg, HCO_3·SO_4-Ca·Mg, HCO_3·SO_4·Cl-Ca·Mg, HCO_3·Cl-Ca·Mg and other types.  相似文献   

中尺度涡冷暖特征的推导     

陈璇  潘静  郑崇伟  张羲  何明 《海洋学报(英文版)》2017,36(3):8-13

为了从理论上解释中尺度涡旋冷暖性质与涡旋旋转方向的关系,本文基于中尺度涡的几何特征,做出如下假设：中尺度涡具有对称的几何形态,涡旋中海洋要素沿径向具有线性化变化的特征。从原始方程组出发,利用柱坐标系和上述假设条件,略去耗散力,推导出了中尺度涡的一些冷暖特征,论证气旋式中尺度涡对应冷涡和反气旋式中尺度涡对应暖涡的涡旋冷暖特征与部分涡旋的观测不符的现象。结果表明,中心对称的形式可以作为对中尺度涡的几何特征的一个理想的形态近似,在考虑上述假设条件的理想环境下,柱坐标系在研究中尺度涡的几何性质上具有一定的优势。  相似文献   

Mineralogical characteristics of polymetallic sulfides from the Deyin-1 hydrothermal field near 15°S,southern Mid-Atlantic Ridge   总被引：1，自引：0，他引：1  

王淑杰  李怀明  翟世奎  于增慧  邵宗泽  蔡宗伟 《海洋学报(英文版)》2017,36(2):22-34

A seafloor hydrothermal field, named Deyin-1 later, near 15°S southern Mid-Atlantic Ridge(SMAR) was newly found during the 22 nd cruise carried out by the China Ocean Mineral Resources Research Development Association(COMRA). Sulfide samples were collected at three stations from the hydrothermal field during the26 th cruise in 2012. In this paper, mineralogical characteristics of the sulfides were analyzed with optical microscope, X-ray diffractometer, scanning electron microscope and electron microprobe to study the crystallization sequence of minerals and the process of hydrothermal mineralization. According to the difference of the ore-forming metal elements, the sulfide samples can be divided into three types:(1) the Ferich sulfide, which contains mainly pyrite and chalcopyrite;(2) the Fe-Cu-rich sulfide consisting predominantly of pyrite, chalcopyrite and isocubanite, with lesser amount of sphalerite, marmatite and pyrrhotine; and(3) the Fe-Zn-rich sulfide dominated by pyrite, sphalerite and marmatite, with variable amounts of chalcopyrite, isocubanite, pyrrhotine, marcasite, galena and gratonite. Mineral precipitations in these sulfides are in the sequence of chalcopyrite(isocubanite and possible coarse pyrite), fine pyrite,sphalerite(marmatite), galena, gratonite and then the minerals out of the dissolution. Two morphologically distinct generations(Py-I and Py-II) of pyrite are identified in each of the samples; inclusions of marmatite tend to exist in the coarse pyrite crystals(Py-I). Sphalerite in the Fe-Zn-rich sulfide is characterized by a"chalcopyrite disease" phenomenon. Mineral paragenetic relationships and a wide range of chemical compositions suggest that the environment of hydrothermal mineralization was largely changing. By comparison, the Fe-rich sulfide was formed in a relatively stable environment with a high temperature, but the conditions for the formation of the Fe-Cu-rich sulfide were variable. The Fe-Zn-rich sulfide was precipitated during the hydrothermal venting at relatively low temperature.  相似文献   

南极半岛近岸海域生物化学要素分布特征及影响因素          下载免费PDF全文

付丹  郑晓玲  王保栋  辛明  滕芳  谢琳萍 《海岸工程》2017,36(1)

基于中国第30次南极科学考察在南极半岛(60°~63°S)近岸海域获取的调查资料,分析了该海域生物化学要素中溶解有机碳(DOC)、总氮(TN)和总磷(TP)分布特征并讨论地形和水团对其的影响。结果表明:2014年夏季南极半岛近岸海域水体DOC浓度变化范围为40.5~78.1μmol/L,平均浓度为66.3μmol/L;TN浓度变化范围为4.2~29.5μmol/L,平均浓度为14.9μmol/L;TP浓度变化范围为0.8~2.9μmol/L,平均浓度为2.0μmol/L。表层DOC呈现研究海域西北部D1断面和东南部D5断面浓度较高,中部DOC浓度较低;表层TN与TP浓度高值区出现在研究海域西部D1断面北部以及南部,中部和东部浓度较低;DOC,TN和TP浓度的垂直分布与海底地形和水团交汇密切相关,水团运动受阻于地形致使生物化学要素在垂直方向再分布。DOC,TN和TP空间分布反映了南极半岛近岸海域生物化学要素复杂的流通,将为合理开发和利用南极资源及环境影响评价提供科学依据。  相似文献   

10MW级海上浮式风机运动特性研究   总被引：2，自引：2，他引：0       下载免费PDF全文

徐应瑜  胡志强  刘格梁 《海洋工程》2017,35(3):44-51

以DTU 10 MW基准风机为研究对象,单柱式平台作为基础支撑结构,使用FAST软件计算分析,考虑单独风、单独波浪以及风浪组合三种环境条件,对10 MW级海上浮式风机的运动特性进行研究。研究发现:系统摇荡是风激励的低频运动和波浪激励的波频运动的合成,气动阻尼削弱系统的波频运动;系统纵荡和纵摇运动存在明显的耦合现象,而垂荡运动和其他方向的运动没有耦合关系;受纵摇影响,转动的风轮产生陀螺惯性力矩,激励首摇运动;随着风机单机容量的增加,风激励的低频运动比例增大,波浪激励的波频运动比例减小。  相似文献   

基于南海定点观测数据的强风场特性研究          下载免费PDF全文

杜宇  王延林  武文华  吕柏呈  岳前进  张立伟 《海洋工程》2017,35(4):36-43

为了满足我国海洋工程抗风设计需求,在南海某海洋平台定点开展了原型测量工作。通过对海面上82 m和29 m两处开展实测工作,获得了冬季寒潮和超强台风"尤特"影响下的风场现场实测数据。利用非平稳过程分析方法对两类强风过程的脉动风分量、湍流强度、阵风因子、湍流积分尺度和脉动风谱等风场特性进行了分析。验证了脉动风分布的高斯性,给出了湍流强度与阵风因子的非线性拟合参数,分析了不同高度处风场特性剖面变化规律,证明了脉动风实测谱与Von Karman经验谱的良好拟合关系。  相似文献   

Numerical investigation of the uplift performance of prestressed fiber-reinforced polymer floating piles     

Pengpeng Ni  Yanlin Zhao 《Marine Georesources & Geotechnology》2017,35(6):829-839

Finite element analyses of prestressed fiber-reinforced polymer floating piles subjected to uplift force have been conducted in this paper. First, parameters of the modified BPE model (bond–slip model at the fiber-reinforced polymer–concrete interface) were calibrated using existing pullout testing data on fiber-reinforced polymer rebars embedded in concrete. Nonlinear spring elements were used in numerical modeling to characterize the bond–slip behavior at the fiber-reinforced polymer–concrete interface. A parametric study was performed to assess the influence of rebar diameter, fiber-reinforced polymer material, embedment length, and concrete strength on the mobilized bond stress. Upon the successful modeling of the pullout performance of fiber-reinforced polymer rebars in concrete, numerical models were developed to investigate the dependence of the uplift performance of floating piles on the prestress level, uplift force, fiber-reinforced polymer type, and compressive strength of concrete.  相似文献