Variable sources for Cretaceous to recent HIMU and HIMU-like intraplate magmatism in New Zealand

Late Cretaceous (99-69 Ma) basaltic intraplate volcanism on and around Zealandia: Tracing upper mantle geodynamics from Hikurangi Plateau collision to Gondwana breakup and beyond

“…Panter et al, 2006), we note that subduction-related (Fig. 3,4), displaying relative Nb enrichment and K and Pb depletions (van der Meer et al, 2016;van der Meer et al, 2017). They also form a crude array on isotope diagrams between a HIMU-like component and a depleted upper mantle MORB source (Fig.…”

“…Although the depletion in K and Pb have been used to argue for amphibole in the source of the Late Cretaceous New Zealand lavas and thus for a subcontinental lithospheric mantle source (SCLM; e.g. Panter et al, 2008;McCoy-West et al, 2016;van der Meer et al, 2017), we note that the classic end member HIMU localities (St. Helena, Mangaia and Tubuaii Islands) with these trace element and isotopic characteristics were erupted on oceanic lithosphere and thus cannot be derived directly from subcontinental lithospheric mantle (SCLM). Although Archean and Early Proterozoic subcontinental lithospheric mantle (SCLM) can have HIMU type compositions, intraplate lavas not located on continental crust of this age could be derived from ocean crust or SCLM recycled through the lower mantle via subduction and mantle plumes (e.g., Hofmann and White, 1982;Weis et al, 2016;Homrighausen et al, 2018).…”

“…Hoernle et al, 2010) -consisting of alkalic seamounts on the Hikurangi Plateau, formed after collision of Hikurangi Plateau with the Gondwana margin, 2) Marlborough Igneous Province (98-94 Ma;Baker et al, 1994;Tappenden, 2003;McCoy-West et al, 2010;Mortimer et al, 2019) -alkalic volcanism on the northern South Island east of the South Alpine Fault, including Lookout, Gridiron, Mandamus and Tapuaenuku Igneous complexes, 3) Westland Igneous Province (92-69 Ma;van der Meer et al, 2016;van der Meer et al, 2017;Mortimer et al, 2019) -tholeiitic to lamprophyric Westland and Hohonu dikes on the northern South Island west of the Alpine Fault, and 4) East Chatham Volcanic Province (86-78 Ma;Panter et al, 2006;Homrighausen et al, 2018;Mortimer et al, 2019) -transitional to alkalic lavas on Chatham Island and seamounts on the East Chatham Rise and the surrounding seafloor. We use the temporal evolution of these four intraplate volcanic provinces to reconstruct processes occurring within the subducted lithosphere and within the mantle beneath the former Zealandia active margin until breakup, including the early history of seafloor spreading between Zealandia and West Antarctica.…”

Late Jurassic to Early Cretaceous magmatism in the Xiong’ershan gold district, central China: implications for gold mineralization and geodynamics

“…Although magmas in intracontinental environments represent a volumetrically minor component of the global magmatic budget (Kuritani et al 2009), they are of considerable geologic interest and have attracted considerable attention (e.g. Gao et al 2004;Van der Meer et al 2017; and references therein), because of their critical geochemical features that distinguish them from 'normal' mid-ocean ridge and arc magmas, but also because they are associated with many world-class ore deposits (e.g. Cr, Ni, Mo and Au deposits, Naldrett, 1999Naldrett, , 2004Pirajno et al 2004).…”

“…Intracontinental magmatism occurring in different tectonic settings has been attributed to several possible processes, such as deep mantle plumes, back-arc spreading, continental rifting, stagnant slab, and lithospheric thinning (e.g. Gao et al 2004Gao et al , 2014Kuritani et al 2009Kuritani et al , 2017Zhao et al 2012;Van der Meer et al 2017). This suggests that the origins of intracontinental magmatism require detailed investigations in each individual setting (Kuritani et al 2009).…”