Tectono–Magmatic Evolution and Metallogenesis along the Northeast Jiangxi Deep Fault, China

Abstract: From the southernmost part of Jiangsu province to the northeastern part of Jiangxi province, China, the Northeast Jiangxi Deep Fault runs for about 400 km length with a width of 30 to 40 km. This fault marks the suture zone of two ter-ranes of Proterozoic age. At the both sides of the fault, Yanshanian granitic activity is recognized. That is, the Dexing-Wuyuan porphyry belt on the NW side of the fault, and the Damaoshan-Lingshan granite belt on the SE side. The former activity is characterized by the occurrence of small stocks of granodioritic composition, rich in siderophile elements but poor in LIL elements. No distinct Eu anomaly is recognized in the REE pattern, and a low initial ⁸⁷Sr/⁸⁶Sr ratio is reported. Magnetite, sphene and apatite are observed as accessory minerals. On the contrary, granitic activity on the SE side of the fault is characterized by the occurrence of composite batholiths, in general of granitic to monzogranitic composition, rich in LIL and alkali elements but poor in siderophile and alkali earth elements. A strong Eu anamaly is recognized in the REE pattern, and initial ⁸⁷Sr/⁸⁶Sr ratios are as high as 0. 716. Fluorite, zircon and REE minerals are observed as accessory minerals. These two contrasting granitic activities are refered to as syntexis– and transformation–types, respectively, following the classification commonly used in China, and have similar petrochemical characteristics to those defined for the magnetite– and ilmenite–series, and I– and S-type granitoids. Considering that the above igneous activity occurred far from the supposed subduction zone along the East Coast of China, intracontinental A-type (continent to continent) subduction is proposed to have occurred northwestwards along the NE Jiangxi Deep Fault during Yanshanian time due to a strong compressional stress from SE to NW. A-type subduction introduced the continental slab to some depth, and resulted in the production of the paired granitic activity observed on both sides of the fault. Many mineral deposits are associated with both granitic belts. In the Dexing-Wuyuan porphyry belt, the Dexing porphyry Cu and Yinshan polymetallic deposits are representative, whereas in the Damaoshan-Lingshan granite belt, several tens of rare metal deposits are known such as the Geyuan Nb–Ta–W–Sn deposits. Metal assemblages of those deposits reflect the source materials of magmas in both granitic belts.     

铋试剂Ⅱ沉淀分离富集、Ar-O_2气氛控制发射光谱测定地质样品中六种贵金属

报道了用铋试剂Ⅱ于ｐＨ４．０沉淀分离富集,混合掩蔽剂消除部分基体干扰元素,Ａｒ－Ｏ２气氛控制消除氰带,垂直电极交流电弧粉末发射光谱同时测定地质样品中六种贵金属的研究成果。该法精确度ＲＳＤ为３．１％～９．０％。Ａｕ、Ｐｔ、Ｐｄ、Ｒｈ、Ｉｒ、Ｒｕ的目视灵敏度分别为０．０２５、０．０２５、０．００５、０．００５、０．０３、０．０２μｇ,实际地质样品加标准回收率在９０％～１０８％之间。     

实验变形煤结构演化的电子顺磁共振研究

通过１４件高温高压实验样品及其原样的电子顺磁共振研究,论述了温度、压力、应力、应变速率和应变强度等是影响变形煤化学结构演化的重要因素,但在不同的煤级中和不同的实验条件下,各因素所起的作用是不同的。变形煤ＥＰＲ参数的演化与镜质组反射率的变化密切相关,并且具有较好的规律性。说明镜质组反射率是煤化学结构演化的外在反映,是煤田构造研究中极为重要的标志物之一。     

北京天文台的WET三通道高速光度计

对北京天文台新近改造成的三通道高速光度计的结构和性能进行介绍,并给出了在兴隆站85公分望远镜的一些实测结果.     

茅山山脉东麓的砾岩层位和时代

通过对茅山东麓砾岩层的实地研究,以５条剖面的岩性、产状和生物等特征为依据,将砾岩分为三类,并分别论述其层位时代。提出了与前人不同的观点。     

地幔对流及其对地壳表层拉张盆地的影响

回顾近十年来在地幔对流方面的最新研究进展,阐述了板块俯冲后在地幔中的演化特征,以及地幔上升流即地幔柱的驱动机制和地质效应。特别介绍了地幔柱对地壳表层拉张盆地形成和充填过程的影响。进一步探讨了地幔柱活动在济阳坳陷的地质表现及其引发的火山岩浆活动、碎屑充填特征。认为盆地演化的阶段性间接反映了地幔对流的阶段性。     

当前我国文武人才的地理分布与南北差异

作为一种文化现象，人才的空间分布规律体现着人才与经济、历史及地理环境之间的关联性。本文选取１７０００多名教授和１６００多名将军作文武人才的地理分析。教授工作地集中的地区依次为北京、上海、四川、湖北、辽宁、江苏、陕西、广东、吉林、天津，籍贯集中的地区依次为江苏、浙江、四川、辽宁、广东、湖南、山东、河北、天津，主要流入地区为北京、上海、陕西、吉林、黑龙江、天津，主要流出地区为浙江、江苏、河北、河南、福建、广东、山东。将军籍贯分布集中程度比教授更为突出，主要集中在江西、湖北、湖南、安徽、河南、四川、山东、福建、河北、陕西。如以县计，则集中在江西的兴国、永新、吉安，湖北的红安、大梧，安徽的金寨、六安，河南的新县，前面三县属中央苏区，后面五县属鄂豫皖苏区。工作在南方和北方教授数基本平衡，但籍贯在南方的约为北方的两倍，籍贯在南方的将军数为北方的两倍多。这种格局反映了文化大革命前的人才流向。近十年，人才流向和人才格局发生变化，不仅国内毕业生，而且国外留学人员也被吸引到南方沿海开放地区，为此，需要新的办法和政策。     

西藏高原地热活动,温泉分布与地球物理场特征

本文根据西藏高原地热活动与温泉分布和各种地球物理场的特征,进行了综合分析与研究,给出了地壳深部要素的统一解释。说明了西藏高原水热分布及其活动原因是由于地壳介质中温度很高,地壳中存在着物质的熔融或部分熔融所致。水热显示是受深部地壳构造与物质运移所制约,其热能是由印度板块与欧亚板块碰撞过程中所产生的热量和岩浆上涌所提供的。     

On characteristic frequencies of a five-component model of magnetospheric plasma

Summary The author gives more general relations derived for characteristic frequencies of a more complex plasma model. One may assume that expressions derived herein, represent a more appropriate approximation of reality, especially in regions of ionospheric and magnetospheric plasma with a higher concentration of heavy ions.     

太阳风湍流和磁层亚暴的一种机制

太阳风的动量涨落将通过磁层边界在磁尾激发磁流体力学波。快磁声波携带扰动能量传到等离子体片中,发展为激波,或者通过激波的相互作用而耗散能量,使等离子体加热。等离子体片中的随机费米加速机制,使麦克斯韦分布尾巴部分的高能量粒子被加速到更高能。在宁静态时,加热、加速与耗散过程平衡。当太阳风的动量或者其涨落较大时,整个加热和加速过程加剧,更多的高能粒子产生,并从等离子体片中逃逸,形成高速的等离子体流注入近地轨道和极区,表现为磁层亚暴过程。利用这种机制,可以解释地球磁层亚暴的定性特征。