We investigate the Li isotope composition and the Li concentrations of metamorphic and sedimentary rocks of the Palaeozoic (Pz) basement in the Central Andes and follow the trace of the Li in the Cenozoic volcanic rocks at the active continental margin. The average Li isotope composition of Pz-basement closely resembles global averages of upper crustal rocks with overlapping, but higher average Li content in the Pz-basement. Lithium isotope composition and content in the Cenozoic volcanic rocks of the Central Volcanic Zone (CVZ) range from mantle-like signatures to Pz-basement compositions with high δ 7 Li values and high Li contents. Evolutionary trends of the Li isotope composition in the CVZ volcanic rocks can be explained by assimilation of the Pz-basement. At a margin-wide scale, the abundance of Li in the CVZ volcanic rocks is higher than that of the Cenozoic volcanic rocks of the active Andean arc north and south of the CVZ. The CVZ volcanic and Pz-basement rocks are considered to be the primary source of Li in world-class Li-deposits in evaporates of the Altiplano-Puna high plateau and its western slope between ca 27° and 20° S. These deposits define the so-called “Lithium-Triangle”, between southern Bolivia, NW Argentina and NE Chile. The pivotal processes of extraction of Li from its primary rock sources and of Li migration from the source rocks to the deposits still await detailed investigation.

中文翻译：

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安第斯弧中部和弧后古生代基底岩和新生代火山岩的锂浓度和同位素特征

我们研究了安第斯山脉中部古生代 (Pz) 基底变质岩和沉积岩的锂同位素组成和锂浓度，并追踪了活动大陆边缘新生代火山岩中锂的踪迹。Pz 基底的平均锂同位素组成与上地壳岩石的全球平均值非常相似，具有重叠，但 Pz 基底中的平均锂含量更高。中央火山带 (CVZ) 新生代火山岩中的锂同位素组成和含量范围从类似地幔的特征到具有高 δ 7 Li 值和高 Li 含量的 Pz 基底成分。CVZ火山岩中Li同位素组成的演化趋势可以通过Pz基底的同化作用来解释。在边际范围内，CVZ火山岩中Li的丰度高于CVZ南北活动安第斯弧的新生代火山岩。CVZ 火山岩和 Pz 基底岩被认为是 Altiplano-Puna 高原及其西坡约 27° 至 20° S 蒸发物中世界级锂沉积物的主要来源。这些沉积物定义了所谓的“锂三角”，位于玻利维亚南部、阿根廷西北部和智利东北部之间。从原生岩源中提取锂以及锂从源岩迁移到矿床的关键过程仍有待详细研究。CVZ 火山岩和 Pz 基底岩被认为是 Altiplano-Puna 高原及其西坡约 27° 至 20° S 蒸发物中世界级锂沉积物的主要来源。这些沉积物定义了所谓的“锂三角”，位于玻利维亚南部、阿根廷西北部和智利东北部之间。从原生岩源中提取锂以及锂从源岩迁移到矿床的关键过程仍有待详细研究。CVZ 火山岩和 Pz 基底岩被认为是 Altiplano-Puna 高原及其西坡约 27° 至 20° S 蒸发物中世界级锂沉积物的主要来源。这些沉积物定义了所谓的“锂三角”，位于玻利维亚南部、阿根廷西北部和智利东北部之间。从原生岩源中提取锂以及锂从源岩迁移到矿床的关键过程仍有待详细研究。