Sulfur and metal fertilization of the lower continental crust

摘要: Abstract Mantle-derived melts and metasomatic fluids are considered to be important in the transport distribution of trace elements subcontinental lithospheric mantle. However, mechanisms that facilitate sulfur metal transfer from upper mantle into lower continental crust poorly constrained. This study addresses this knowledge gap by examining a series sulfide- hydrous mineral-rich alkaline mafic–ultramafic pipes intruded Ivrea–Verbano Zone Italian Western Alps. The relatively small ( Stratigraphic relationships, mineral chemistry, geochemical modeling phase equilibria suggest represent open-ended conduits within large magmatic plumbing system. earliest formed pipe rocks were olivine-rich cumulates reacted with produce orthopyroxene, amphibole phlogopite. Sulfides precipitated as immiscible liquid droplets retained matrix silicate crystals scavenged metals percolating melt. New high-precision chemical abrasion TIMS U–Pb dating zircons one indicates these emplaced at 249.1 ± 0.2 Ma, following partial melting pods metasomatized during Eo-Variscan oceanic subduction (~ 420–310 Ma). thermal energy required generate was most likely derived crustal extension, decompression subsequent asthenospheric rise orogenic collapse Variscan belt Unlike previous models, outcomes significant temporal between occurrence metasomatism, emplacement pipes. We argue multi-stage process is very effective mechanism fertilize commonly dry refractory volatiles. During four-dimensional evolution thermo-tectonic architecture any given terrain, volatiles stored may become available sources for ore-forming processes, thus enhancing prospectivity block margins wide range systems.