FEATURES OF THE GEOLOGICAL STRUCTURE OF THE ORIENT BASIN

Abstract

The description of the geological structure of the Orient basin is presented. The Oriente Basin is shown to include that part of the back-arc syncline system located in Ecuador and northeastern Peru between the Vaupes Swell geological basement arcs in the east-west line in southern Colombia and the Contoya arc in northern Peru. At the same time, the basin demonstrates significant asymmetry with a steeper western edge, characterized by a structural dip at an angle of 5-10 ° and a more gently descending eastern edge, with a dip of less than 2 °. The density and amplitude of intra-basin faults and folds significantly decrease towards the southern part of the basin. At the same time, the width of the basin decreases significantly to the north (as it approaches the transverse Vaupes Arch basin), and the increased structural desformation is the result of the expansion of the Jurassic-Cretaceous period and subsequent compression by constrained rocks in the Tertiary period. To the east, on the continental shield, the thickness of the sedimentary deposits of this basin decreases, while on the western side (as we approach the pre-Tertiary outcrops to the day surface of the Subandian zone), there is little evidence of thinning of regional deposits of the Cretaceous - Lower Tertiary periods, different from the "thickening" by the outer edge of the shelf, which probably rests in depth on granite intrusions.