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41.
小兴安岭鹿鸣大型钼矿LA-ICP-MS锆石U-Pb和辉钼矿Re-Os年龄及其地质意义 总被引:8,自引:0,他引:8
鹿鸣钼矿是小兴安岭地区于近年发现的大型斑岩型钼矿床。为探讨研究区成岩成矿关系及其地质意义,在对矿化特征分析的基础上,采用LA-ICP-MS锆石U-Pb技术对鹿鸣地区含矿二长花岗岩测年,获得成岩年龄为 (187.1±1.2) Ma (n=15, MSWD=0.70) 。通过辉钼矿样品Re-Os同位素分析,获得等值线年龄为(177.4±3.5) Ma (n=11, MSWD=0.71) ,加权平均年龄为(178.08±0.79) Ma (n=11,MSWD=0.46)。两种方法获得的年龄大致相近,表明它们形成于同一成岩成矿系统。鹿鸣钼矿成岩成矿年龄,与乌奴格吐山铜钼矿、兰家沟钼矿和杨家杖子钼矿等矿床辉钼矿Re-Os同位素年龄相近,表明包括小兴安岭地区在内的我国东北地区广泛存在早侏罗世岩浆-成矿作用。微量元素和同位素指纹显示,鹿鸣钼矿形成于地壳挤压向拉伸转换的构造环境,成矿物质为壳幔混合来源。 相似文献
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Takami Morita Shigeyoshi Otosaka Kou Nishiuchi Haruya Yamada Masayuki Minakawa 《Marine pollution bulletin》2010,60(8):1193-1199
60Co were detected in common octopus specimens collected in the East China Sea in 1996-2005. The source of 60Co has remained unclear yet. Stable isotope analyses showed that there was no difference in stable Co concentrations between octopus samples with 60Co and without 60Co. This result showed that the stable Co in the digestive gland of octopus potentially did not include a trace amount of 60Co and the source of 60Co existed independently. Furthermore, investigations of octopus in other area and other species indicated that the origin of the source of 60Co occurred locally in the restricted area in the East China Sea and not in the coastal area of Japan. Concentrations of 60Co have annually decreased with shorter half-life than the physical half-life. This decrease tendency suggests that the sources of 60Co were identical and were temporary dumped into the East China Sea as a solid waste. 相似文献
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Xiuying Xing Zhiqing Kou Ziyi Huang Jiin-Jen Lee 《Pure and Applied Geophysics》2013,170(6-8):1149-1168
Tsunamis waves caused by submarine earthquake or landslide might contain large wave energy, which could cause significant human loss and property damage locally as well as in distant region. The response of three harbors located at the Pacific coast (i.e. Crescent City Harbor, Los Angeles/Long Beach Port, and San Diego Harbor) to six well-known tsunamis events generated (both near-field and far-field) between 2005 and 2011 are examined and simulated using a hybrid finite element numerical model in frequency domain. The model incorporated the effects of wave refraction, wave diffraction, partial wave reflection from boundaries, entrance and bottom energy dissipation. It can be applied to harbor regions with arbitrary shapes and variable water depth. The computed resonant periods or modes of oscillation for three harbors are in good agreement with the energy spectral analysis of the time series of water surface elevations recorded at tide gauge stations inside three harbors during the six tsunamis events. The computed wave induced currents based on the present model are also in qualitative agreement with some of the reported eye-witness accounts absence of reliable current data. The simulated results show that each harbor responded differently and significantly amplified certain wave period(s) of incident wave trains according to the shape, topography, characteristic dimensions and water depth of the harbor basins. 相似文献
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Diffusion coefficients of dense gases in liquids can be measured by considering two-phase binary nonequilibrium fluid mixing in a closed cell with a fixed volume. This process is based on convection and diffusion in each phase. Numerical simulation of the mixing often requires accurate algorithms. In this paper, we design two efficient numerical methods for simulating the mixing of two-phase binary fluids in one-dimensional, highly permeable media. Mathematical model for isothermal compositional two-phase flow in porous media is established based on Darcy’s law, material balance, local thermodynamic equilibrium for the phases, and diffusion across the phases. The time-lag and operator-splitting techniques are used to decompose each convection–diffusion equation into two steps: diffusion step and convection step. The Mixed finite element (MFE) method is used for diffusion equation because it can achieve a high-order and stable approximation of both the scalar variable and the diffusive fluxes across grid–cell interfaces. We employ the characteristic finite element method with moving mesh to track the liquid–gas interface. Based on the above schemes, we propose two methods: single-domain and two-domain methods. The main difference between two methods is that the two-domain method utilizes the assumption of sharp interface between two fluid phases, while the single-domain method allows fractional saturation level. Two-domain method treats the gas domain and the liquid domain separately. Because liquid–gas interface moves with time, the two-domain method needs work with a moving mesh. On the other hand, the single-domain method allows the use of a fixed mesh. We derive the formulas to compute the diffusive flux for MFE in both methods. The single-domain method is extended to multiple dimensions. Numerical results indicate that both methods can accurately describe the evolution of the pressure and liquid level. 相似文献
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南海海域大油气田与中国东南海区油气地质分析 总被引:1,自引:0,他引:1
本文以中国南海海域崖13-1、流花11-1和大熊油田等三大油气田的地质特征和油气模式为参照,分析了中国东南海域台西南盆地,台湾海峡盆地及毗邻地区的油气地质条件,指出与基底隆起有关的背斜构造、基底风化壳型油气藏、裂隙型油气藏和与裂谷地堑-半地堑构造有关的近源三角洲、缓翼斜坡带等是进一步开展油气勘查的目标和重点。 相似文献
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Bo Li Bei-bei Kou Bin Li Jing Li Jing Zeng Qing-lei Niu Yu-tao Shao Ke-wei Zhang Hao-yu Yu Ying-sheng Wang 《China Geology》2022,5(2):293-299
Traditional suction anchor technology is mainly used in the fields of subsea structure bearing foundations, single-point mooring systems and offshore wind power. It is characterized by providing sufficient lateral and vertical bearing capacities and lateral bending moment. The anchor structure of a traditional suction anchor structure is improved with wellhead suction anchor technology, where a central pipe is added as a channel for drilling and completion operations. To solve the technical problems of a low wellhead bearing capacity, shallow built-up depth, and limited application of conductor jetting in the second production test of natural gas hydrates (NGHs) in the South China Sea (SCS), the China Geological Survey (CGS) took the lead in independently designing and manufacturing a wellhead suction anchor, which fulfilled the requirements of the production test. This novel anchor was successfully implemented in the second production test for the first time, providing a stable wellhead foundation for the success of the second production test of NGHs in the SCS.©2022 China Geology Editorial Office. 相似文献
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