This study explores the potential of fluvial sediments as unconventional reservoirs of Critical and Strategic Raw Materials (CRMs and SRMs), encouraged by EU’s Critical Raw material act (2023)[3] Focusing on streams in the Northern Apennines of Italy, this research assesses sediment geochemistry in drainage basins characterized by ophiolitic and volcanogenic massive sulfide (VMS) lithologies[4] associated with the external Ligurides Succession. These rocks are globally associated with major reserves of metals such as Cu, Ni, Co, PGE, Cr, Ti, and V[2], suggesting that derived sediments may serve as secondary sources. Sediment was sampled along the Nure, Taro and Scoltenna River. Chemical data were collected across multiple grain sizes via X-Ray Fluorescence (XRF). Enrichment factors (EFs) were calculated for a group of CRMs using Al₂O₃ as a stable normalizer and Upper Continental Crust (UCC) values as reference. Nure and Taro rivers show significant enrichment in sand, particularly in Cr (up to 15) and Ni (up to 20), compared to the UCC. In contrast, Scoltenna shows minor anomalies, mainly for Copper (Cu) and Zinc (Zn) in mud Additionally, mineral separation is performed using a Frantz magnetic separator. Transition metals and Mg are one order of magnitude higher in the magnetic fractions, compared to the nonmagnetic one, which retains Si, Ca and Sr composed mainly of calcite, quartz and feldspars. Enrichments in the sand rather than mud could suggest that CRMs are present as detrital mineral grains rather than adsorbed species, enhancing their extractive potential.
Geochemical Assessment of Fluvial Sediments as Unconventional Sources of Critical Raw Materials in the Northern Apennines
Rotta Davide
;Bianchini Gianluca;Bonadiman Costanza;Tassinari Renzo;Tessari Umberto
2025
Abstract
This study explores the potential of fluvial sediments as unconventional reservoirs of Critical and Strategic Raw Materials (CRMs and SRMs), encouraged by EU’s Critical Raw material act (2023)[3] Focusing on streams in the Northern Apennines of Italy, this research assesses sediment geochemistry in drainage basins characterized by ophiolitic and volcanogenic massive sulfide (VMS) lithologies[4] associated with the external Ligurides Succession. These rocks are globally associated with major reserves of metals such as Cu, Ni, Co, PGE, Cr, Ti, and V[2], suggesting that derived sediments may serve as secondary sources. Sediment was sampled along the Nure, Taro and Scoltenna River. Chemical data were collected across multiple grain sizes via X-Ray Fluorescence (XRF). Enrichment factors (EFs) were calculated for a group of CRMs using Al₂O₃ as a stable normalizer and Upper Continental Crust (UCC) values as reference. Nure and Taro rivers show significant enrichment in sand, particularly in Cr (up to 15) and Ni (up to 20), compared to the UCC. In contrast, Scoltenna shows minor anomalies, mainly for Copper (Cu) and Zinc (Zn) in mud Additionally, mineral separation is performed using a Frantz magnetic separator. Transition metals and Mg are one order of magnitude higher in the magnetic fractions, compared to the nonmagnetic one, which retains Si, Ca and Sr composed mainly of calcite, quartz and feldspars. Enrichments in the sand rather than mud could suggest that CRMs are present as detrital mineral grains rather than adsorbed species, enhancing their extractive potential.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
