A combined petrological, geochemical and geochronological study of the magmatic rocks surrounding the Logatchev hydrothermal field.

对洛加切夫热液田周围岩浆岩进行岩石学、地球化学和地质年代学的综合研究。

• 批准号: 54904092
• 负责人: Professor Dr. Jürgen Koepke
• 金额: --
• 依托单位: GEOMAR Helmholtz-Zentrum für Ozeanforschung Kiel
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/54904092?language=en
• 关键词: combined; petrological; geochemical; geochronological; study

For the last period of the SPP we suggest a joint research project of (experimental) petrology and igneous geochemistry in order to study the magmatic rocks in the region of the Logatchev hydrothermal field. A large number of samples is accessible or will be collected which we can use to study the transport of magmas (and energy) from the mantle to the crust, the formation of the crust, and the interaction between the magmatic rocks and hydrothermal fluids. Petrological, geochemical and isotopic analysis of plutonic and volcanic rocks from the Logatchev field will establish their relationship and depth of crystallization. To achieve these goals, different approaches are used: (1) phase equilibria are modeled in a wide range of αH2O and fD2 and include equilibrium, fractional, and polybaric crystallization calculations; (2) glass inclusions in minerals are investigated to understand the behavior and importance of volatiles in differentiation processes and during ascent; (3) gabbros are investigated to constrain depth and temperature of the differentiation process based on natural samples in comparison with the results from the theoretical simulations. Petrologic and geochemical studies of the magmatic rocks will reveal reactions with hydrothermal fluids, which may have led to crustal remelting and assimilation. Uranium series dating will yield age estimates of the volcanic processes and thus of the timing of magma ascent to the surface as possible heat sources. This project will thus represent an essential link within the SPP between the magmatic processes in the mantle and crust and the hydrothermal processes at the seafloor and the shallow crust.

在SPP的最后阶段，我们建议进行（实验）岩石学和火成岩地球化学的联合研究项目，以研究洛加切夫热液田地区的岩浆岩。大量的样品是可获得的或将被收集，我们可以用来研究岩浆（和能量）从地幔到地壳的运输，地壳的形成，以及岩浆岩和热液流体之间的相互作用。对Logatchev油田的深成岩和火山岩进行岩石学、地球化学和同位素分析，将确定它们之间的关系和结晶深度。为了实现这些目标，采用了不同的方法：（1）在α H_2O和fD_2范围内模拟相平衡，包括平衡、分馏和多压结晶计算：（2）研究矿物中的玻璃包裹体，以了解挥发分在分异过程和上升过程中的行为和重要性;（3）在天然样品的基础上，研究了辉长岩对分异作用深度和温度的制约作用，并与理论模拟结果进行了比较。岩浆岩的岩石学和地球化学研究将揭示与热液流体的反应，这可能导致地壳重熔和同化。铀系定年法将对火山活动过程作出年龄估计，从而对岩浆上升到地表作为可能的热源的时间作出估计。因此，该项目将成为SPP内地幔和地壳岩浆过程与海底和浅地壳热液过程之间的重要联系。