Phanerozoic hot spot traces and paleogeographic reconstructions of the Siberian continent based on interaction with the African large low shear velocity province

摘要

We review intraplate magmatism in Siberia and its folded surroundings from 480. Ma to the present. We describe several large igneous provinces (LIPs) and the intervals in which they were continuously formed within the limits of the Siberian continent: the Altay-Sayan Early Paleozoic magmatic area (598-446. Ma), the Altay-Sayan LIP (408-393. Ma), the Viluy LIP (380-350. Ma), the Barguzin-Vitim LIP (310-275. Ma), the Late Paleozoic rift system of Central Asia (318-242. Ma), the Siberian traps and West Siberian rift system (250-249. Ma), the East-Mongolian and West-Trans-Baikalian LIP (228-195. Ma), and a number of various aged Late Mesozoic and Cenozoic rift zones and magmatic areas (from 160. Ma to the present day).Following Lawver and Muller (1994), Kharin (2000), Lawver et al. (2002) and Chernysheva et al. (2005), we accept the position of the Icelandic hot spot under the Siberian trap area at the Permo-Triassic boundary. That enables us to estimate the geographic coordinates of the Siberian trap location at 250. Ma (they are the same as Iceland today). Presently the Icelandic hot spot is situated above the African large low shear velocity province (LLSVP) that indicates a hot mantle plume. We suggest a set of paleogeographic reconstructions of the Siberian continent for which we evaluate the paleolatitude based on the paleomagnetic data and estimate the paleolongitude position by placing Siberia above the African LLSVP. Furthermore, we estimate the geographic coordinates for other ancient hot spots in the framework of the African LLSVP that we consider to be responsible for the intraplate magmatism during different time periods in the Phanerozoic eon.Available rare element and isotopic characteristics of the intraplate magmatic rocks of Siberia enable us to determine three primary sources - moderately depleted mantle (PREMA), enriched mantle (EM-I and EM-II) - of the mantle origin magma. We propose that the model explains the interaction of the hot mantle plume including hot spots (plume tails) with the Siberian intraplate magmatism areas throughout the Phanerozoic eon.