Structure and Age of the Metamorphic Core Complex of the Burgutui Ridge (Southwestern Transbaikal Region)

摘要

In the 1990s, peculiar Late Mesozoic structures of intracontinental extension, the so-called metamorphic core complexes (MCC), previously considered inliers of the Early Precambrian basement, were defined in the Transbaikal region (Fig. 1). Geochronological substantiation of these structures was; however, insufficient, except for the Zagan core complex. Special geo-structural investigations of the Burgutui metamorphic core make it possible to fill this gap. The lithostructural paragenesis of the Burgutui Ridge MCC is developed in the area of ～1200 km~2 in the Selenga-Chikoi interfluve. The MCC represents probably an autonomous structure, although one cannot rule out that this structure can be an element of the larger Butuliin-Nur MCC defined in Mongolia. Its discrimination was substantiated by both published and unpublished geological data.