Procambrian sources of diamonds in phanerozoic placers

Abstract

Introduction: Manifestations of Precambrian producibility were identified for many diamond-bearing regions in the world. However, the number of known Precambrian primary sources of diamonds is rather limited. Methodology: The results of a summary of the great amount of factual data from complex studies of diamonds from the Upper Paleozoic, Mesozoic, and recent sedimentary strata of the Siberian platform (SP) allowed obtaining new data on the specific features of the composition and distribution of the mineral in recent and ancient deposits of the main diamond-bearing regions of the Leno-Anabar, Central Siberian, and Tunguska sub-provinces. Results and discussion: The area of the Kyutyunginsky graben and the neighbouring territories that can be promising for the discovery of kimberlite bodies with specific diamonds was outlined in the north-east of the platform. It was shown for the Central Siberian sub-province that the region of the development of individual macroassociations of diamonds is limited by a certain diamond-bearing region where Upper Paleozoic and Mesozoic deposits of different ages are represented. Conclusions: The specific features of the diamonds from the SP placers indicate that there are multiple primary sources and there are yet undiscovered kimberlite bodies in many diamond-bearing regions. The use of typomorphic features of crystals is important for the reconstruction of the exogenous history of diamonds on their path from primary sources to their modern presence in placers. It is essential for paleogeographic reconstructions of the distribution of ancient productive strata and for the determination of the source areas of diamond-bearing materials. The similarity of typomorphic features of diamonds in sedimentary strata established in certain diamond-bearing regions indicates the formation of secondary reservoirs due to the drainage of more ancient productive strata (including Precambrian ones) or Middle Paleozoic primary sources. We confirmed the polygenetic nature of mineral associations of diamonds from placers within certain diamond-bearing regions, which can be used for the prediction of and search for the primary sources of the mineral.