Waiting for Yorsget – 21-22 June 2021 - Young Researchers in Structural Geol ogy and Tectonics – University of Catania
Building an orogen-scale database of giant quartz veins: the GIVEPY (Giant Quartz Veins of
the Pyrenees) database
E. González-Esvertit1*, E. Gómez-Rivas1, A. Canals1, J. M. Casas2
1 Departament de Mineralogia, Petrologia i Geologia Aplicada. Universitat de Barcelona, 08028, Barcelona (Spain).
2 Departament de Dinàmica de la Terra i l’Oceà. Universitat de Barcelona, 08028, Barcelona (Spain).
Quartz veins are ubiquitous in orogenic settings, within zones of intense deformation such as faults and
fractures in the upper (brittle) crust and shear zones in the lower (ductile) crust. The dimensions of quartz veins
can vary dramatically within the same tectonic setting, from millimetric to hectometric thicknesses and from
metric to kilometric lengths. However, despite their ubiquity, there are still many open questions about the
formation mechanisms of the largest veins, also known as “Giant” Quartz Veins (GQVs). As GQVs are visible in
satellite and photogrammetric imagery, they can be analysed by remote sensing mapping and other computer-
assisted methods. Worldwide, geological and geographical surveys and institutions offer a wide range of
georeferenced geological information, often freely available and regularly updated, which includes high-
resolution orthophotography, 3D photogrammetry, satellite imagery and detailed vector-format geological maps.
These open access datasets can thus be used to statistically analyse the occurrence, orientation, distribution and
host rock variability of GQVs, comparing them to other geological structures (i.e., shear zones, fractures and
faults) to gain new insights into the structural controls on vein emplacement at the large scale.
We present a systematic workflow for characterizing GQVs from a GIS-based approach, using the Pyrenees
as a natural laboratory. This fold and thrust belt represents an excellent environment for the study of GQVs,
specially from a remote sensing approach, due to the large datasets provided by the French (BRGM), Spanish
(IGME) and Catalan (ICGC) geological surveys. Geological and geographical information have been used to
obtain the main attributes of hundreds of GQVs in the Pyrenees, and the final product is presented as a dynamic
database: the GIVEPY (GIant quartz VEins of the PYrenees) database. It includes the shape, coordinates, regional
setting, outcropping area, trace azimuth and descriptions of host rock/s (lithology, age and type) of each indexed
GQV, representing a macrostructural approach of their orientation and distribution along the chain that can be
replicated in other tectonic settings or with other geological structures, such as regional faults, folds, fractures or
Preliminary results indicate that the GQVs of the Pyrenees are hosted either in late Neoproterozoic to
Carboniferous metasedimentary rocks, Variscan gneisses, late-Variscan granitoids and Mesozoic to Cenozoic
sedimentary rocks. Veins mainly consist of discontinuous massive quartz bodies SE-NW to SW-NE oriented and
are mostly arranged in the central sector of the Eastern Pyrenees (Canigó and Roc de Frausa Massifs). They are
frequently emplaced alongside other regional structural features, such as thrust faults and shear zones of different
age. The largest veins (15 km length) are located in the Canigó Massif, although other hectometric to kilometric
quartz bodies are also ubiquitous along the chain, from its eastern end in Cap de Creus Massif to its western
termination in the Basque Massifs.