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101.
The Lanping basin is a significant Pb–Zn–Cu–Ag mineralization belt of the Sanjiang Tethyan metallogenic province in China. Over 100 thrust-controlled, sediment-hosted, Himalayan base metal deposits have been discovered in this basin, including the largest sandstone-hosted Pb–Zn deposit in the world (Jinding), and several Cu ± Ag ± Co deposits (Baiyangping, Baiyangchang and Jinman). These deposits, with total reserves of over 16.0 Mt Pb + Zn, 0.6 Mt Cu, and 7000 t Ag, are mainly hosted in Meso-Cenozoic mottled clastic rocks, and strictly controlled by two Cenozoic thrust systems developed in the western and eastern segments of the Lanping basin.To define the metallogenic history of the study area, we dated nine calcite samples associated with copper sulfides from the Jinman Cu deposit by the Sm–Nd method and five molybdenite samples from the Liancheng Cu–Mo deposit by the Re–Os method. The calcite Sm–Nd age for the Jinman deposit (58 ± 5 Ma) and the molybdenite Re–Os age for the Liancheng deposit (48 ± 2 Ma), together with previously published chronological data, demonstrate (1) the Cu–Ag mineralization in the western Lanping basin mainly occurred in three episodes (i.e., ∼56–54, 51–48, and 31–29 Ma), corresponding to the main- and late-collisional stages of the Indo–Asian orogeny; and (2) the Pb–Zn–Ag (±Cu) mineralization in the eastern Lanping basin lacked precise and direct dating, however, the apatite fission track ages of several representative deposits (21 ± 4 Ma to 32 ± 5 Ma) may offer some constraints on the mineralization age. 相似文献
102.
采用室内暴露试验方法,以单细胞凝胶电泳技术(SCGE)检测,研究了Cu、Pb不同浓度梯度与不同暴露时间联合染毒对泥鳅卵细胞DNA的损伤.结果表明,各Cu、Pb浓度组DNA平均迁移长度增加,与阴性对照组比较差异有显著性(P<0.05).此外,随着Cu、Pb染毒剂量的增加,各试验组DNA的平均迁移长度逐渐增加,在试验浓度梯度范围内(Cu 0.01mg/L+Pb 0.05mg/L、Cu 0.10mg/L+Pb 0.50mg/L、Cu 0.25mg/L+Pb 0.75mg/L),存在较为显著的剂量-效应关系(P<0.05),但未见明显的时间-效应关系(P>0.05).Cu、Pb可引起泥鳅卵细胞凋亡和DNA损伤,卵细胞的不同损伤水平可望作为较为理想的水环境基因毒性指标. 相似文献
103.
The marine–estuarine polychaete Capitella is an indicator of organic pollution and plays important roles in sewage waste cycling. The antidepressant fluoxetine can be accumulated in streams and sewage effluents and it could pose a hazard to infauna. Effects of fluoxetine on feeding and growth of Capitella teleta were investigated through the exposure to 0, 0.001, 0.03, 0.3 and 3.3 μg/g dry weight sediment-spiked fluoxetine during 18 days. No effects of fluoxetine concentrations were observed on egestion rates, body weight and size-specific egestion rates. Fluoxetine favoured the occurrence of males with abnormal genital spines. This suggests that fluoxetine can have important reproductive implications. Further studies are recommended to assess potential detrimental effects on benthic infauna inhabiting close to sewage treatment plants. 相似文献
104.
Based on the results of previous studies and under the direction of the theory of “ore deposit genesis”, the authors made
use of high temperature and high pressure experimental facilities and conditions at the Tectono-geochemistry Research Room
under the State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, and put
the focus on the multi-source of tectonically controlling ore-forming materials, the characteristics of multi-stage and multi-episode
hydrothermal activities and mineralization and the characteristics of multi-genesis and multi-ore deposition so as to shed
light on the metallogenic mechanisms of super-large Cu and Au deposits. In addition simulating experiments were made on multi-stage
and multi-episode tectonic activities and rock and ore deformation, multi-stage and multi-episode tectonic activities and
mobilization and migration of ore-forming materials, and multi-stage and multi-episode tectonic activities and superimposition
and enrichment of ore-forming materials. The experimental results showed that under the action of multi-stage and multi-episode
tectonic stress the deformation and fragmentation of not only rocks and ores have been intensified, and but also the ore-forming
materials originally disbursed in the rocks and ores have been mobilized and migrated and superimposed and enriched. The experimental
results also provided the scientific experimental data and grounds for deep-going research on the rules of metallogenesis
and geneses of super-large ore deposits in the Dexing region, Jiangxi Province. 相似文献
105.
我国西南地区斑岩矿床区域成矿环境 总被引:5,自引:2,他引:3
本文对我国西南地区斑岩Cu(-Mo-Au)矿床形成的区域成矿环境进行了总结研究。我国西南地区斑岩矿床,构造上位于全球特提斯斑岩成矿带东段,与青藏高原演化密切相关,形成于青藏高原演化不同阶段。我国西南地区斑岩矿床形成时代为晚三叠世、早白垩世、古近纪和中新世等4个时期。斑岩矿床形成的区域成矿环境具有多样性,包括俯冲造山岛弧、同碰撞、后碰撞和大陆转换板块边界等四类构造环境。根据斑岩矿床成岩成矿时代和成矿环境,我国西南地区斑岩矿床可划分为义敦-中甸印支期斑岩成矿带、玉龙-马拉松多古近纪斑岩成矿带、丽江-金平古近纪斑岩成矿带、冈底斯古近纪-新近纪斑岩成矿带和班公湖-怒江燕山期斑岩成矿带等五个成矿带。与世界上多数斑岩矿床一样,我国西南地区斑岩矿床与区域深大走滑断裂存在着明显的空间分布关系。 相似文献
106.
107.
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109.
矿体产于印支期黑云角闪花岗闪长岩与寒武系(未分,∈?)变质岩接触带,F1压扭性断裂控制矿体的形态和展布。成因类型为热液接触交代一矽卡岩型铁锌矿。 相似文献
110.