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211.
YIN Qingqing XIANG Xinkui YU Zhendong YANG Xiufeng WANG Tianchen ZHONG Bo TAN Rong LIAO Jianhai ZHU Yuansong 《《地质学报》英文版》2020,94(6):1860-1873
The Pengshan Sn-polymetallic ore field is located in the southeastern part of the Yangtze block, spanning the southeast edge of the MLYDZ and the northern edge of the mid-segment of the Jiangnan Uplift, and on one side of the MLYDZ. The studies of LA–ICP–MS zircon U–Pb chronology and petrogeochemistry for Early Cretaceous acid granites from the Pengshan ore field were carried out in this paper. We report zircon U–Pb geochronology and whole-rock geochemistry for acid granites in the Pengshan ore field. The zircon U–Pb ages of the muscovite-granite, biotite adamellite and granite-porphyry are 127.6 ± 1.7 Ma, 126.9 ± 1.6 Ma and 126.6 ± 2.0 Ma, respectively. The granites in Pengshan are characterized by a high silicon content and are rich in alkali. They belong to high-potassium, calc-alkaline, peraluminous granite. The rocks have a relatively high Rb/Ba ratio, and the data points for muscovite-granite and biotite adamellite all fall within the clay-rich sources region, near the pelite-derived end-member, showing that the Pengshan muscovite-granite and biotite adamellite mainly originated from the partial melting of metapelites with high maturity. The transformation of the compressional and extensional tectonics in this region approximately 128 Ma obviously lags behind that in the mid-segment of the Jiangnan Uplift (135 Ma), but occurred earlier than the MLYDZ (126 Ma). The Pengshan ore field extends from the mid-segment of the Jiangnan Uplift to the MLYDZ. Although the tectonic stress field is constrained by the combination of the two secondary tectonic units, the time of tectonic system transformation is closer to the MLYDZ because the spatial orientation of the area is enclosed in the MLYDZ. Relevant geophysical and drilling data confirm the rationality of Pengshan–Ao’xia as a multi-center vertical zoning ore field, and show the scientificity of the prospecting idea of abutting joint between the north-west of Pengshan area and the south-east of Ao’xia area. 相似文献
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On July 31st, 2016, an earthquake of MS5.4 occurred in Cangwu County, Guangxi Zhuang Autonomous Region, which is the first MS ≥ 5.0 earthquake in coastal areas of southern China in the past 17a. The moderate earthquake activities have come into a comparatively quiet period in coastal areas of southern China for decades, so the study about the Cangwu MS5.4 earthquake is very important. However, differernt research institutions and scholars have got different results for the focal depth of the Cangwu MS5.4 earthquake. For this reason, we further measured the focal depth by using CAP method and sPL phase method.
sPL phase was first put forward by Chong in 2010. It is often observed between P and S wave of continental earthquakes with epicentral distance of about 30km to 50km. The energy of sPL phase is mainly concentrated on the radial component. Arrival time difference between sPL phase and direct P wave is insensitive to epicentral distancs, but increases almost linearly with the increase of focal depth. Based on these characteristics and advantages, sPL phase method is chosen to measure the focal depth of Cangwu MS5.4 earthquake in the paper.
First of all, we selected the broadband waveform data through seismic stations distributed mainly in Guangxi and adjacent provinces from Data Management Centre of China National Seismic Network and Guangxi Earthquake Networks Center. And an appropriate velocity model of Cangwu area was constructed by the teleseismic receiver function method. Then, the focal mechanism and focal depth of Cangwu MS5.4 earthquake were determined by using the CAP(Cut and Paste)method. Next, we compared the synthetic waveforms simulated by F-K forward method of different focal depth models with the actual observed waveforms. According to the difference of arrival times between sPL and Pg phases, we finally obtained the focal depth of Cangwu earthquake. The results show that the focal depth is 11km measured by CAP method and 9km by sPL phase method. Based on the focal mechanism solution, isoseismal shapes, aftershocks distributions and investigation on spot, we conclude that the Cangwu MS5.4 earthquake is a left-lateral strike-slip earthquake which occurred in the upper crust. Our preliminary analysis considers that the seismogenic structure of Cangwu earthquake is a north-northwest branch fault, and the control fault of this earthquake is the Hejie-Xiaying Fault. 相似文献
214.
为了提高地震应急信息发布效率,解决传统地震应急信息服务不能满足当前需要的问题,基于地震网站内容管理信息系统,以地震信息数据为基础,根据信息类别和属性对Java easysite平台进行技术开发,设计了地震信息直播、地震参数、震区背景等核心功能模块。通过自动获取地震数据库信息系统,实现了平台各个功能模块信息的快速发布。该应用已被布置在中国地震局网站平台上,实现了地震应急信息平台的智能管理,进一步保证了地震应急信息的发布。 相似文献
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白沙河流域地下水及营养盐向海湾输送 总被引:4,自引:0,他引:4
根据白沙河流域自然地理和水文地质特征 ,在大量室内外试验的基础上分别运用水量均衡法、断面法和咸淡水界面法 ,估算了白沙河流域地下水向海湾的输送水量及营养盐输送量。 3种方法估算的结果表明 ,白沙河流域地下水向海湾输送量较大且受降雨影响显著 ,丰水年 (1998年 )地下水入海量高达 2 .2× 10 6m3 ,是枯水年 (1992年 )入海量的 2倍。另外 ,农田灌溉及大气降雨淋滤土壤中所施肥料使该区地下水中营养盐浓度 (尤其是硝酸盐氮浓度 )严重超过了饮用水水质标准 ,每年有 (4~ 11)× 10 6mol硝酸盐氮随地下水入海 ,相比之下 ,可溶性二氧化硅含量稳定 ,氨氮、亚硝酸盐氮、总磷含量较低 ,排海量较少。 相似文献
219.
海水钝顶螺旋藻富硒及其含硒藻蓝蛋白的研究 总被引:1,自引:0,他引:1
研究了亚硒酸钠梯度浓度对海水钝顶螺旋藻Spirulina platensis生长及藻胆蛋白含量的影响,对含硒藻蓝蛋白进行分离纯化,得到含硒藻蓝蛋白纯品。结果表明,硒添加浓度小于100mg.L-1时,对藻体生长有一定的促进作用,其生物量、藻蓝蛋白和别藻蓝蛋白含量有增加,藻体硒含量及富硒系数明显高于文献报道的相似条件下的淡水螺旋藻;纯化的含硒藻蓝蛋白溶液在弱光照、低温、pH4—8的范围内稳定性较好;含硒藻蓝蛋白的光谱特性与藻蓝蛋白相比几乎没有差异,紫外与可见光吸收光谱特征吸收峰在280nm和620nm,荧光激发峰在558nm,室温条件下最大荧光发射峰在655nm,说明海水钝顶螺旋藻富集硒后及海水的胁迫对其藻蓝蛋白的光谱特性没有明显影响。 相似文献
220.