Spatial and temporal variations in mantle redox state beneath the Massif Central, France

法国中部地块的第三纪和第四纪火山作用在一个大的地理区域以橄榄岩捕虏体的形式取样了次大陆岩石圈地幔（SCLM）。Lenoir et al.（2000）和Downes et al.（2003）的地球化学研究表明，存在两个不同的地幔域，分别位于北纬45°30′和南纬45°30′。这里的目标是追踪地幔氧化还原状态的变化，这将为欧洲这部分地区的SCLM演化提供进一步的线索，例如，如果这两个域记录了不同的氧化还原状态。除了空间变化外，还可以通过分析不同喷发年龄（~20 Ma至最近）火山中心的捕虏体来研究其时间变化。由于经常观察到这种相互作用可以改变氧化还原状态，因此也将监测到新陈代谢的影响。这项研究将为西欧地下浅层沉积物的化学演化提供重要的新信息。

The Tertiary and Quaternary volcanism of the Massif Central, France, has sampled the subcontinental lithospheric mantle (SCLM) in the form of peridotite xenoliths over a large geographical area. Geochemical studies by Lenoir et al. (2000) and Downes et al. (2003) suggest the existence of two distinct mantle domains, lying north and south of 45° 30’ latitude, respectively. The goal here is to trace the variations in mantle redox state that will provide further clues about the evolution of the SCLM in this part of Europe, for example if these two domains record distinctive redox states. In addition to spatial variations, temporal changes can be studied by analysing xenoliths from volcanic centers with different eruption ages (~20 Ma to recent). The effects of metasomatism will also be monitored since such interactions are often observed to modify redox state. This study will provide important new information on the chemical evolution of the SCLM beneath Western Europe.