Approaches to the diamond potential of the Siberian craton: A new paradigm

Abstract

Synthesis of new and published data on diamond occurrences in the Siberian craton provides a perspective on the diamond potential of the region in terms of a new paradigm. The new diamond potential paradigm for the Siberian craton includes several main postulates:(i) existence of Precambrian diamond sources;(ii) diversity of Precambrian primary diamond deposits and related diamond populations; prevalence of diamond varieties associated with suprasubduction magmatism;(iii) single kimberlitic type of Phanerozoic primary diamond deposits;(iv) Middle Paleozoic kimberlites as the main hosts of economic primary diamond deposits.Exploration for Precambrian primary diamond deposits is unreasonable: they are detectable within limited basement exposures and may be deeply eroded; their types and signatures remain unknown, which obscures the exploration targets. However, diamond may exist in Mesozoic and Cenozoic placers derived from such deposits.On the other hand, Middle Paleozoic kimberlites, including those in the northeastern Siberian craton, may store economic amounts of diamond; indicator minerals in placers from these kimberlites can be discriminated from their counterparts of poor or barren Mesozoic kimberlites using specially selected mineralogical criteria described in the paper. The new paradigm highlights the true diamond potential of the Siberian craton and allows outlining realistic exploration objectives for primary and placer deposits.