Tourmaline trace element composition in volcanogenic massive sulfide Cu-Zn-Pb and clastic-dominated Zn-Pb deposits with applications to mineral exploration

Tourmaline from thirteen volcanogenic massive sulfide (VMS) deposits, three clastic-dominated (CD) Zn Pb deposits, and four barren sediment-hosted tourmalinites were analyzed for major, minor, and trace elements to identify chemical criteria that distinguish tourmaline in VMS and CD deposits from other barren and mineralized environments. Tourmaline from VMS is mainly dravitic, with some deposits showing schorlitic and uvitic compositions, whereas CD Zn Pb and barren tourmalinite tourmaline spans the schorl-dravite transition and dravitic compositions, with few exceptions showing uvitic and foititic compositions. Tourmaline major element composition from VMS and CD is governed by heterovalent coupled substitutions, reflecting local processes specific to each deposit. In barren tourmalinites, the compositions are mainly controlled by the chemical composition of the host metasedimentary units. The VMS tourmaline shows higher Al, Mg, and V, whereas CD has higher Ca, Co, K, Mn, Li, La, Ce, Eu, Zn, and Pb; tourmalinites show higher Fe, Na, Ti, Sr, Cr, Sc, Sn, Ga, and Cu. A partial least-squares discriminant analysis (PLS-DA) model is used to classify VMS deposits, CD Zn Pb deposits, and barren tourmalinites. The results show that VMS tourmaline correlates with Mg, Sn, Ga, and V; CD Zn Pb tourmaline correlates with Pb, Zn, K, Mn, and Eu; and tourmaline from barren tourmalinites correlates with Fe, Ti, and Sr. These elements were used to build bivariate classification plots using element ratios that enhance the geochemical distinction of VMS and CD Zn Pb tourmaline from tourmaline in granite-related Sn W, orogenic gold, porphyry Cu-Mo-Au, iron oxide‑copper‑gold, and barren geological environments. • Chemical data of tourmaline from VMS, CD Zn Pb, and tourmalinites are reported. • Tourmaline composition from VMS, CD Zn Pb, and tourmalinites is compared. • PLS-DA using tourmaline chemistry is used to classify the investigated deposits. • Element ratios are used to discriminate VMS and CD Zn Pb from other deposits types.