A tectonothermal model for the formation of an orogen at the post-collisional stage (by the example of the Yenisei Ridge, Eastern Siberia)

Using geological, geophysical, and thermophysical parameters, we performed a numeric modeling of the thermal regime of a collisional process by the example of the Yenisei Ridge Neoproterozoic orogen in the southwestern framing of the Siberian platform. The results yielded by the described 3D numerical models and by the one-dimensional parametric modeling of the thermal effect of crustal matter differentiation allowed reconstructing the main tectonothermal processes of the collisional stage of this structure formation. The performed modeling allows taking into account the local particularities of the crustal thermal state of the structure under discussion and at the same time it allows determining the general regularities, typical of orogens on post-collisional stages. We have established that it is the action of three factors that significantly influences the thermal regime: the radiogenic heat of the intrusions, high heat flow anomalies, and clustering of the Glushikha complex leucogranitic bodies in the central region of the Central Angara terrane. Our studies have shown that tectonic processes combined with diachronous magmatic activity can significantly affect the course of collisional orogens' thermal history. (C) 2011, V.S. Sobolev IGM, Siberian Branch of the RAS. Published by Elsevier B.V. All rights reserved.