Italian Emilia Romagna Region has more than 100 dismissed mine sites, exploited in the last century as war Cu supply, many occurring in Volcanogenic Massive Sulfide Deposits (VMS), metal sulfide deposits occurring after underwater volcanic eruptions, associated with hydrothermal events in submarine environments and are divided based on ore composition (Cu, Cu-Zn, Cu-Zn-Pb group) and environmental formation (Cyprus, Kuroko, Besshi) [1]. In this region, VMS deposits occur as pods within small bodies of ophiolitic basalts cropping out as olistoliths in the Northern Apennine External Ligurian units and owe their origin to the metal-rich hydrothermal circulation which developed quartz-sulfide veins when mixed with seawater through a fissures network [2]. The area is characterized by sequences of pillow lavas associated with serpentinite and gabbro breccias, radiolarian cherts, limestones, and abundant serpentinized mantle peridotites [3]. A group of samples from the Boccassuolo ophiolite (Modena province) was geochemically analyzed for both major and trace elements: the results agree with those found in literature [e.g., 1], classifying them as Cu and Cu-Zn deposits, with Cu up to 5818 ppm, 200 times Upper Continental Crust, UCC, and Zn up to 7941, 118*UCC, and as Cyprus-type in term of environment formation. The Pb content is very low, <1 ppm. All the veins observed at the macroscale are made of quartz, as revealed by calcimetry analyses. Another group from Montecreto (Modena province) was collected and analyzed, although results are still under observation. These samples are sulfide-enriched, with sulfide minerals up to 8 mm in size, and they are made of both quartz and calcite veins, as tested on the field. For both sites, radiogenic (Sr-Nd-Pb) and stable (S-C) isotopic analyses, as well as mineralogical and in-situ analyses area planned to provide additional information on the enrichment and distribution of VMS deposits in the Emilia Romagna Region. References: [1] Zaccarini, F. & Garuti, G. (2008). Min. and Pet., 94, 61-83, doi.org/10.1007/s00710-008- 0010-9 124 [2] Saccani, E. (2015). Geos. Fron., 6, 4, 481-501, doi.org/10.1016/j.gsf.2014.03.006 [3] Kiss, G.B., et al. (2023). Minerals, 13, 1, 8, doi.org/10.3390/min13010008 125
Revived interest in historically dismissed Volcanogenic Massive Sulfide (VMS) deposit of the Emilia Romagna region (Italy): Critical Raw Materials (CRMs) petrological and geochemical study
Tagliacollo Lisa
Primo
;Bonadiman CostanzaSecondo
;Saccani Emilio;Bianchini Gianluca;Brombin Valentina;Renzo TassinariUltimo
2024
Abstract
Italian Emilia Romagna Region has more than 100 dismissed mine sites, exploited in the last century as war Cu supply, many occurring in Volcanogenic Massive Sulfide Deposits (VMS), metal sulfide deposits occurring after underwater volcanic eruptions, associated with hydrothermal events in submarine environments and are divided based on ore composition (Cu, Cu-Zn, Cu-Zn-Pb group) and environmental formation (Cyprus, Kuroko, Besshi) [1]. In this region, VMS deposits occur as pods within small bodies of ophiolitic basalts cropping out as olistoliths in the Northern Apennine External Ligurian units and owe their origin to the metal-rich hydrothermal circulation which developed quartz-sulfide veins when mixed with seawater through a fissures network [2]. The area is characterized by sequences of pillow lavas associated with serpentinite and gabbro breccias, radiolarian cherts, limestones, and abundant serpentinized mantle peridotites [3]. A group of samples from the Boccassuolo ophiolite (Modena province) was geochemically analyzed for both major and trace elements: the results agree with those found in literature [e.g., 1], classifying them as Cu and Cu-Zn deposits, with Cu up to 5818 ppm, 200 times Upper Continental Crust, UCC, and Zn up to 7941, 118*UCC, and as Cyprus-type in term of environment formation. The Pb content is very low, <1 ppm. All the veins observed at the macroscale are made of quartz, as revealed by calcimetry analyses. Another group from Montecreto (Modena province) was collected and analyzed, although results are still under observation. These samples are sulfide-enriched, with sulfide minerals up to 8 mm in size, and they are made of both quartz and calcite veins, as tested on the field. For both sites, radiogenic (Sr-Nd-Pb) and stable (S-C) isotopic analyses, as well as mineralogical and in-situ analyses area planned to provide additional information on the enrichment and distribution of VMS deposits in the Emilia Romagna Region. References: [1] Zaccarini, F. & Garuti, G. (2008). Min. and Pet., 94, 61-83, doi.org/10.1007/s00710-008- 0010-9 124 [2] Saccani, E. (2015). Geos. Fron., 6, 4, 481-501, doi.org/10.1016/j.gsf.2014.03.006 [3] Kiss, G.B., et al. (2023). Minerals, 13, 1, 8, doi.org/10.3390/min13010008 125I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.