THE METALLOGENY OF TERRESTRIAL AND EXTRATERRESTRIAL LARGE IGNEOUS PROVINCES (LIPS) (Invited Presentation)

Large Igneous Provinces (LIP) events occur on Earth but also on Mars, Venus, the Moon and Mercury. As defined on Earth, they are large volume (>0.1 Mkm³; frequently above >1 Mkm³), short duration (<5 m.y. or multiple short pulses of magmatism spanning up to a few 10s of m.y.), mainly mafic (-ultramafic) events of intraplate affinity. LIPs consist of volcanic packages and a plumbing system of mafic sills, layered intrusions, and giant dyke swarms. They represent significant reservoirs of energy and metals that can either drive or contribute to a variety of metallogenic systems. This in turn indicates that LIP events (or analogues) on Mars, Venus, the Moon and Mercury may also have generated significant mineralization.

The lack of a history of plate tectonics (except possibly on early Mars) suggests these planetary bodies would not have formed plate boundary-related mineralization (e.g., porphyry-type Cu-Mo-Au deposits). However, extensive LIP analogue magmatism on these planetary bodies may have driven metallogenic systems that formed mineral deposits similar to those associated with LIPs on Earth. In addition, the differing characteristics of these planetary bodies mean that they may also host LIP-related mineral deposit types not found on Earth.

Lunar mare may host voluminous Fe-Ti mineralization and may be associated with the genesis of Fe-Ti-V, Cr, and potentially native Fe-Ni metal mineralization. Lunar K, rare earth element, and phosphorus (i.e., KREEP) rich rocks may also have concentrated these and other elements (e.g. U and Th) in sufficient amounts to make viable ore deposits. In addition, lunar regolith material derived from LIP-related magmatism may host significant helium-3 resources derived from the solar wind far in excess of the amount present on Earth. In comparison, Martian LIP magmatism has the potential to have generated orthomagmatic Ni-Cu-PGE sulfide and cumulate chromite mineralization. The weathering of these basalts (as well as any magmatic sulfides) may have generated gossans and abiotic banded iron formations that are somewhat analogous to some of the weathering-related LIP mineralization on Earth (e.g. bauxites, laterites). This presentation will provide an overview of these styles of mineralization as well as the potential for LIP-related metallogenesis across the Solar System.