Geology of giant quartz veins and their host rocks from the Eastern Pyrenees (Southwest Europe)

Giant Quartz Veins (GQVs) are ubiquitous in different tectonic settings and, besides being often related to hydrothermal ore deposits, also represent large-scale fingerprints of the structural and geochemical history of the rocks in which they are hosted. Here we present detailed geological maps and interpretations of three key areas of the Eastern Pyrenees where GQVs are well exposed. The studied rocks record different styles of deformation and are representative of common settings of the Pyrenees where GQVs are present: pre-Variscan metasedimentary and metavolcanic rocks, late Variscan granitoids, and Mesozoic and Cenozoic sedimentary rocks. GQVs in the study areas formed along pre-existing brittle and ductile structures or at locations with lithological heterogeneities, and have alteration haloes of silicified host rocks. The geological maps and interpretations presented here contribute to gain insights into the formation mechanisms of GQVs and into the structural constraints on fluid flow and mineral reactions at different depths of the Earth’s crust.

巨型石英脉（Giant Quartz Veins, GQVs）广泛分布于各类构造环境中，不仅常与热液矿床伴生，同时也是其所赋存围岩的构造与地球化学演化历史的大型示踪标志。本数据集提供了东比利牛斯山脉三处GQVs出露良好的关键区域的详细地质图件与解译成果。本次研究的围岩记录了多种变形样式，且可代表东比利牛斯山脉产出GQVs的典型构造环境：华力西期前变质沉积岩与变质火山岩、华力西晚期花岗岩体，以及中生代与新生代沉积岩。研究区内的GQVs多沿先期存在的脆性、韧性构造或岩性不均一区域形成，并伴有围岩硅化蚀变晕圈。本次公开的地质图件与解译成果，有助于深入解析GQVs的形成机制，以及地壳不同深度流体运移与矿物反应所受的构造约束。