在赛诺曼—土伦边界处的全球变化和锰沉积     

Dick.  GR 张伯君 《海洋地质译丛》1994,(2):51-59

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黑龙江依兰地区蓝片岩相变质作用及其演化   总被引：2，自引：2，他引：0  

韩晓萌  郑常青  徐学纯  韩玉宝  徐久磊 《岩石学报》2018,34(4):1139-1153

依兰地区蓝片岩作为黑龙江杂岩的重要组成部分,其变质作用演化问题一直存在较大争议。本文通过对依兰地区蓝片岩的岩相学及矿物微区化学成分的研究,并运用PERPLE_X软件,在Na_2O-CaO-K_2O-MnO-FeO-MgO-Al_2O_3-SiO_2-H_2O-TiO_2-O(Fe_2O_3)(NCKMnFMASHTO)体系下对石榴石冻蓝闪石片岩(g-brs-wnc-act-phn-chl-ep-ab-stlp)、绿泥绿帘蓝闪石片岩(gl-brs-wnc-act-chl-ep-stlp)和白云母蓝闪石片岩(gl-wnc-phn-ab-ep-chl-sph)进行了相平衡模拟,并分别获得了500~525℃/1.14~1.2GPa、480℃/1.4GPa、450~500℃/0.95~1.2GPa峰期变质作用的温压条件,其峰期变质级别都达到了绿帘-蓝片岩相。结合前人发表的地球化学和年代学数据,建立了蓝片岩相岩石的顺时针变质演化P-T轨迹。研究区蓝片岩的形成标志着新生洋壳的俯冲作用,同时代表古亚洲洋构造域的结束和环太平洋构造域的开始。相平衡模拟中,P-T轨迹记录了峰期前温压条件递增的过程,温度峰期与压力峰期同时到达,说明蓝片岩相变质作用是在俯冲过程中实现的,而不是折返过程中达到的。减压阶段的轨迹近于平行追溯进变质轨迹,揭示与进变质过程相似的地热体制下(11～14℃/km),相对缓慢的抬升过程  相似文献   

变质流体研究的意义和途径     

徐学纯 《华北地质》1991,(3)

变质流体作为变质岩石的重要组成部分,以流体包裹体的形式被圈闭在矿物中。它是变质作用过程峰期变质阶段矿物结晶时而封存的与矿物处于平衡状态的流体相。流体包裹体是矿物结晶时流体环境的唯一真实和客观的记录。是唯一能够获得的变质过程流体性质和物化条件的实际样品。流体包裹体的观察和认识随着岩石学研究的进展早已开  相似文献   

The capture efficiency map: the capture zone under time-varying flow   总被引：3，自引：0，他引：3  

Festger AD  Walter GR 《Ground water》2002,40(6):619-628

The capture zone or contributing area of a ground water extraction well can be defined as that portion of the aquifer from which the well draws its water. Accurate delineation of capture zones is important in many ground water remediation applications and in the definition of wellhead protection areas. Their mathematical delineation is often simplified by using quasi-steady-state models based on time-weighted average pumping rates and background hydraulic gradients. We present a new semianalytic approach for the definition of capture zones under transient-flow conditions. We then use this approach to evaluate the effects of time variations in the direction of the background hydraulic gradient on capture. Results are presented in the form of capture efficiency maps (CEMs). Although the area contributing to a given well is found to generally expand relative to the steady-state average capture zone when the gradient direction varies, the zone of 100% capture may expand or contract depending on site-specific conditions. We illustrate our CEM approach by applying it to the design of a plume containment system.  相似文献   

鲁东造山带榴辉岩变质作用特征及其动力学机制   总被引：4，自引：1，他引：3  

凌贤长  卢良兆  徐学纯 《岩石矿物学杂志》2000,19(2):140-151

岩相学研究表明,广泛发育鲁东造山逞中的榴辉岩可以划分为四种类型：第一类为含柯石英及其假象榴辉岩;么二类为含蓝晶石 、黝帘石及多硅白云母等榴辉岩;第三类为石榴石－绿辉石－石英组合榴辉岩;第四类为（角闪石）石榴石－辉及有关岩石（非典型“榴辉岩”）。这四类榴辉岩峰期前进变质矿物共生组合及Ｐ－Ｔ条件估算结果均显示它们应属于高温与超高压变质作用产物,其变质作用ＰＴｔ轨迹表现为顺时针演化趋势,反映出板块俯冲碰  相似文献   

变质动力学开放研究实验室简介     

徐学纯 《长春地质学院学报》1995,25(3):355-356

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基础铀矿勘探测量及其对早期识别潜在天然翁害区的重要性：苏丹实例     

Pars.  GR 刘腾耀 《国外铀金地质》1992,(1):70-75

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Polycyclic aromatic hydrocarbons (PAHs) in small island coastal environments: a case study from harbours in Guam, Micronesia     

Denton GR  Concepcion LP  Wood HR  Morrison RJ 《Marine pollution bulletin》2006,52(9):1090-1098

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Anthropogenic effects on the smalltooth sawfish (Pristis pectinata) in the United States     

Seitz JC  Poulakis GR 《Marine pollution bulletin》2006,52(11):1533-1540

Bycatch mortality in net fisheries was the major reason for the decline of the endangered smalltooth sawfish, Pristis pectinata, in the United States. These fisheries have been reduced or eliminated in some states including Florida--where most smalltooth sawfish are currently found in the United States. To determine whether other factors are still affecting this species, we obtained non-net fishery entanglement, injury, and mortality data by soliciting information from anyone who may have encountered this species. Smalltooth sawfish were damaged by marine pollution (e.g., polyvinyl chloride pipe, monofilament line, non-monofilament line) and injured by humans. Examples of injuries caused directly by humans include removal of rostra, shooting an individual with a powerhead, and shooting another with arrows. Many people are aware that the smalltooth sawfish is protected by state and federal laws, but some are still not aware of (or willing to accept) this status. The impacts of marine pollution and injuries directly caused by humans on this endangered species can be ameliorated by incorporating fisher education into the conservation and management processes.  相似文献   

辽西杨家杖子向斜构造下部隐伏花岗岩接触变质作用     

郑常青  崔一兵  胡鹏月  徐学纯  刘云虎  黄明国 《世界地质》2019,(3)

为了进一步确定杨家杖子钼矿区向斜构造下部是否存在隐伏花岗岩地质体,以及隐伏花岗岩接触变质作用特征,进行了大地电磁测深和钻探验证,结果显示:上富儿沟JK--1井于1 727 m、杨家杖子岭前矿南沟JK-2井于1 514. 79 m、喜鹊沟JK--5井于1 159. 92 m分别钻遇到花岗岩地质体;大地电磁测深显示杨家杖子向斜构造下部1 160～1 750 m存在隐伏花岗岩地质体,虹螺山大岩基与杨家杖子向斜构造下部的花岗岩体是连通的。以喜鹊沟JK-5井为例,隐伏花岗岩接触变质影响厚度780 m±,接触变质内带,角岩--矽卡岩带,变质程度为辉石角岩相,影响厚度约500 m,发育辉钼矿化;接触变质中带,透辉石大理岩带,角闪角岩相,影响厚度100 m±,发育含有透辉石大理岩;接触变质外带,为含透闪石微晶大理岩,钠长石--绿帘角岩相,宽度180 m,180 m以上过渡到未变质石灰岩。杨家杖子钼矿的主要矿体均产于石灰岩与花岗岩接触带的矽卡岩和斑状花岗岩中,属于矽卡岩-斑岩型钼矿床。  相似文献