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211.
212.
利用LA-ICP-MS锆石U-Pb法,测得与成矿有关的青海祁漫塔格地区虎头崖矿床Ⅵ矿带花岗岩的成岩年龄为(233.6±1.8) Ma(MSWD=1.2,n=17)。地球化学特征显示:花岗岩属高钾钙碱性、弱过铝质花岗岩;样品的稀土元素组成以总体右倾,轻、重稀土分异明显和具明显的负铕异常为特征;微量元素具有富集Rb、Th、U、La、Nd等大离子亲石元素,亏损Ba、Sr、Nb、P、Ti等元素的特点。Sr-Nd同位素组成特征显示,花岗岩的源区可能是富集岩石圈地幔。初步研究认为,虎头崖矿床Ⅵ矿带花岗岩可能形成于中、晚三叠世碰撞后碰撞的构造背景下。 相似文献
213.
214.
The composition of quartz inclusions and trace elements in ore indicate that gold-bearing fluid in the Xiadian gold deposit,Shandong Province,stemmed from both mantle and magma,belonging to a composite origin.Based on theoretical analysis and high temperature and high pressure experimental studies,gold-bearing fluid initiative localization mechanism and the forming environment of ore-host rocks are discussed in the present paper.The composite fluid extracted gold from rocks because of its expanding and injecting forces and injecting forces and flew through ore-conducive structures,leading to the breakup of rocks.The generation of ore-host faults and the precipitation of gold-bearing fluid occurred almost simultaneously.This study provides fur-ther information about the relationships between gold ore veins and basic-ultrabasic vein rocks and intermediate vein rocks,the spatial distribution of gold ore veins and the rules governing the migration of ore fluids. 相似文献
215.
前陆盆地类型及其沉积动力学研究综述 总被引:15,自引:2,他引:15
从前陆盆地的特点及类型入手,综述了前陆盆地研究的热点内容,最新方法及其沉积动力学进展状况,揭示了前陆背景下盆地充填序列的构成及内部演化特征,指出了盆地的沉积-地层格架与冲断造山带的幕式活动之间的响应关系。 相似文献
216.
Yingxia Lu Baosheng Li Xiaohao Wen Shifan Qiu Fengnian Wang Dongfeng Niu Zhiwen Li 《中国地理科学(英文版)》2010,20(3):243-251
The upmost segment(Holocene series)of the Milanggouwan stratigraphic section(MGS1)in the Salawusu River valley shows 11 sedimentary cycles of dune sands and fluvio-lacustrine facies,or dune sands and paleosols.The analysis of the magnetic susceptibility of this segment suggests that there are 11 magnetic susceptibility cycles with the value alternating from low to high,in which the layers of the dune sands correspond to the lower value of the magnetic susceptibility and the layers of fluvio-lacustrine facies and paleosols correspond to the higher peaks.The study reveals that the low and high magnetic susceptibility values indicate the climate dominated by cold-arid winter monsoon and warm-humid summer monsoon of East Asia,respectively,and the study area has experienced at least 22 times of mil-lennial-centennial scales climate alternation from the cold-arid to the warm-humid during the Holocene.In terms of the time and the climate nature,the variations basically correspond to those of the North Atlantic and some records of cold-warm changes in China as well.They might be caused by the alternation of winter and summer monsoons in the Mu Us Desert induced by global climate fluctuations in the Holocene. 相似文献
217.
We established a line (screened) of Portunus trituberculatus by selectively breeding individuals that survived from challenge with Vibrio alginolyticus, and compared the response of screened and unscreened (control) P. trituberculatus challenged with V. alginolyticus. We measured superoxide dismutase, catalase, acid phosphatase, alkaline phosphatase, and peroxidase activity and the content of hemocyanin in the plasma and phenoloxidase activity in serum. The cumulative survival rate after 24-h challenge with V. alginolyticus was significantly higher in the screened crabs than in the unscreened crabs (P<0.05). T-SOD and PO activity were significantly lower in the screened stock than in the unscreened stock (P<0.05). POD, CAT, and ACP activity and hemocyanin content were significantly higher in the screened stock than in the unscreened stock. Our results suggest that the screened stock was more resistant to infection. Furthermore, the indices we measured may be used to evaluate the health state of P. trituberculatus. 相似文献
218.
王淑军 《国土资源导刊(湖南)》2015,(2):30-33,38
通过对湘东北金宏金矿控矿因素、成矿规律、找矿方向等进行的野外调查和室内分析,表明:(1)中元古界冷家溪雷神庙组(Pt2l)为矿源层;(2)北西西向压扭性剪切断裂带为该区金矿的主要控矿构造;北北东向压扭性剪切断裂带是该区金矿的次要控矿构造;(3)该两组压扭性剪切断裂构造交汇部位是金矿富集最有利部位,很容易形成品位较高、厚度较大的矿床;该矿区矿床远景规模可达大型。 相似文献
219.
????????????????????????????Σ??????з??????????????????5????Σ????8????????????????ε????????????????????????????????????β-?????κ????媲?????ξ??з??????????????????????????0.499??0.272????????????????????????Σ????????????С??????????£???????????????????????ó???β-?????κ?????-????ε????????????????????????6??7??3.8 km??5.9??3.3 km?? 相似文献
220.
Yingchun Lv Rong Zheng Tao Zuo Yuming Wang Zhaojie Li Yong Xue Changhu Xue Qingjuan Tang 《中国海洋大学学报(英文版)》2014,13(5):825-829
Sea cucumbers are traditional marine food and Chinese medicine in Asia. The rapid expansion of sea cucumber market has resulted in various problems, such as commercial fraud and mislabeling. Conventionally, sea cucumber species could be distinguished by their morphological and anatomical characteristics; however, their identification becomes difficult when they are processed. The aim of this study was to develop a new convenient method of identifying and distinguishing sea cucumber species. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of mitochondrial cytochrome oxidase I gene (COI) was used to identifing five sea cucumber species (Apostichopus japonicus, Cucumaria frondosa, Thelenota ananas, Parastichopus californicus and Actinopyga lecanora). A 692 bp fragment of COI was searched for BamHI, KpnI, PstI, XbaI and Eco31I restriction sites with DNAMAN 6.0, which were then used to PCR-RFLP analysis. These five sea cucumber species can be discriminated from mixed sea cucumbers. The developed PCR-RFLP assay will facilitate the identification of sea cucumbers, making their source tracing and quality controlling feasible. 相似文献