Passive Structural Control on Skarn Mineralization Localization: A Case Study from the Variscan Rosas Shear Zone (SW Sardinia, Italy)

Minerals

Antonio Funedda¹  Stefano Naitza¹  Antonio Attardi¹  Matteo Luca Deidda¹  Fabrizio Cocco¹  Dario Fancello¹ 

[1] Department of Chemical and Geological Sciences, University of Cagliari, Cittadella Universitaria, S.S. 554 Bivio per Sestu, Monserrato, 09042 Cagliari, Italy;

关键词: tectonic slices;    mineralization;    polydeformed basement;    fluid circulation;    brittle–ductile transition;    mafic intrusion;   

DOI  :  10.3390/min12020272

来源: DOAJ

【 摘 要 】

The case study presented here deals with the Pb-Zn-Cu skarn ores hosted in the Rosas Shear Zone (RSZ), a highly strained domain located in the external zone of the Sardinian Variscan chain. The RSZ is characterized by several tectonic slices of Cambrian limestones within a strongly folded and foliated Cambrian-Ordovician siliciclastic succession, intruded by late Variscan granites and mafic dykes. Based on geological mapping, structural and microscope analyses, our results show that the skarn ores in the RSZ are an example of passive structurally controlled mineralization. The RSZ was structured close to the brittle–ductile transition and, once exhumed to shallower crustal levels, acted as plumbing system favoring a large-scale granite-related fluid circulation. The paragenesis and the mineralization style of the skarn vary slightly according to the peculiarity of the local structural setting: a tectonic slice adjacent to the mafic dyke; an intensely sheared zone or a discrete thrust surface.

【 授权许可】

Unknown