Ta,Nb花岗岩的矿物平衡及岩石成因

Ｔａ、Ｎｂ花岗岩是一种含黄玉和萤石的锂（白）云母钠长花岗岩，它的主要矿物与含Ｆ矿物之间的平衡关系是理解其岩石成因的关系。     

Rb-Sr和Pb同位素在限定花岗质岩石源岩性质中的地质意义——以姑婆山花岗杂岩体为例

锶、钕和铅同位素在追踪花岗岩源区物质,讨论源岩演化的历史,从而深入研究花岗岩成因及其成矿特征等方面越来越受地质学家重视。对于年青花岗岩类,尤其是中生代花岗岩类,Sm-Nd同位素研究源岩性质往往不及Rb-Sr同位素有效。因此,本文只用Rb-Sr和Pb同位素对华南一个重要的中生代花岗岩体——姑婆山花岗杂岩体源区岩石进行讨论,以说明     

CrⅥ载体氧化试剂的制备和应用研究——紫苏醇选择氧化合成紫苏醛

研究了紫苏醇选择氧化合成紫苏醛的反应,考察了氧化剂负载量、氧化剂用量和反应温度对紫苏醛产率的影响.结果表明,采用负载量为2 mmol/g的CrO3/SiO2载体氧化试剂,在二氯甲烷溶剂中于室温下搅拌反应1.5 h,可将紫苏醇选择性氧化成紫苏醛,产率为82.6%.     

秀中藏秀 奇外出奇——三清山国家地质公园

三清山国家地质公园位于江西省上饶市东北。它主要是花岗岩高山尖峰地貌,主峰玉京峰海拔1817m,主要景区在海拔1300～1600m之间,有各种类型的山峰、怪石,其中以"巨蟒出山"和"东方女神"最为神奇、逼真,国内外罕见。公园有南清园、万寿园、三清宫、玉京峰等主要景区,这些地貌景观的发育主要取决于两组垂直节理和一组水平节理,形成高山、深谷、陡坡、尖峰。这里植被茂密、山清水     

On the genetic classification and tectonic implications of the Early Yanshanian granitoids in the Nanling Range, South China

Early Yanshanian (Jurassic) granitoids are widespread in the Nanling Range of South China, and are associated with numerous non-ferrous and rare metal mineral deposits. These granitoids consist mainly of slightly peraluminous biotite monzogranites and K-feldspar granites that are closely associated in time and space with subordinate amphibole-bearing granites and muscoviteand garnet-bearing granites. In most previous studies, the biotite-bearing granites were classified as crustal transformation-type (corresponding to the S-type) granites which were interpreted to be derived from the regional Paleoproterozoic meta-sedimentary rocks. In this paper, we re-analyze the geochemical characteristics of a number of representative Early Yanshanian Nanling granitoids. There exists a clear negative correlation between SiO2 and P2O5 for the studied granitoids. The Early Yanshanian Nanling granitoid suites (including amphibole-bearing granodiorites→biotite monzogranites→K-feldspar granites→two-mica (muscovite) granites) are metaluminous to slightly peraluminous I-type or fractionated I-type granites. They were derived predominantly from Proterozoic igneous protoliths. The juvenile crust and/or newly mantle-derived materials might also have been involved in some of these granites. In addition, the Iand fractionated I-type granites are closely associated in time and space with minor amount of A-type felsic and mafic volcanic and intrusive rocks as well as alkaline rocks. All these rocks constitute a typical assemblage of anorogenic, intraplate magmatism, suggesting a dominant lithospheric extensional regime for the Nanling Range and neighboring region during the Early Yanshanian period.     

Early Paleozoic granite in Nujiang River of northwest Yunnan in southwestern China and its tectonic implications

The Nujiang region along the China-Burma border in the western Yunnan has received a great deal of attention and has been considered to be the important channel of southeastward escape of the Tibetan Plateau[1-4]. This channel is bordered by the Red River-Ailao Mountain left-literal strick-slip fault in the east and Gaoligong- Sagaing right-literal strick-slip fault in the west[5-7]. Within this channel, it is still not clear to which tectonic     

不同条件下花岗岩中声波传播速度的规律

应用超声波混凝土测试仪(TICO),系统研究了含水率、裂纹、应力和温度对花岗岩内波速传播的影响.实验发现含水率对波速影响比较大,饱和岩样的声波传播速度高于不饱和岩样的声波传播速度;人工预制裂纹对声波传播速度影响不大;单轴压缩条件下,声波传播速度随应变增加逐渐降低;在同一温度(160℃)下,波速随保温时间的增加而逐渐降低;在对岩样逐渐加热情况下,初始加热阶段波速略有升高,当温度达到60℃时,岩样波速达到峰值,之后随着温度继续升高其波速逐渐下降;波速随温度变化具有一定的尺寸效应.实验结果表明,声波在岩石内传播速度受很多外在因素影响,并具有一定的传播规律.     

401矿区铀矿床地质地球化学特征及其地下堆浸评价

40 1矿区贫铀花岗岩成岩后经过三期水溶液流体的改造作用 :早期高温热液的碱交代作用使花岗岩中的铀活化转移 ,此活性铀是形成铀矿床的物质基础 ;中期中低温热液是沿断裂上升的深源富 CO2 流体与大气降水的混合产物 ,它浸出了花岗岩中的活性铀 ,并迁移至有利的断裂构造部位 ,富集成脉状热液铀矿床 ;晚期地表水沿控矿断裂向下渗滤 ,铀矿床遭受表生淋滤 ,其矿石的物理化学性质发生改变 ,为地下堆浸创造了有利条件     

华山花岗岩动力性质的三轴试验研究

对华山花岗岩进行动三轴试验研究,分析了其抗压强度、弹性模量、泊松比与应变率及围压间关系.结果表明:围压不变时,随应变率的增大抗压强度增大,而弹性模量和泊松比变化不明显;应变率相同时,围压增大抗压强度也变大,但弹性模量和泊松比变化较小.基于以上试验结果,分别采用莫尔-库仑准则和霍克-布朗准则,定量地给出了华山花岗岩抗压强度与应变率以及围压间表达式.采用莫尔-库仑准则分析时,强度的变化由黏聚力占主导;采用霍克-布朗准则分析时,应变率效应主要表现在单轴抗压强度的改变上,而材料参数m变化很小.     

高地下水位条件下花岗岩残积土路堤的毛细特性研究

为了解高地下水位条件下花岗岩残积土低路堤的毛细特性,以福建省典型花岗岩残积土为例,采用自制的毛细水上升试验系统进行不同压实度和初始含水量条件下的毛细水上升试验,结合数值模拟研究毛细水上升规律.结果表明:典型花岗岩残积土路堤土的毛细水初期上升高度及速度服从对数函数或幂函数模型,达到平衡湿度的时间约5a,其最终上升高度约3...