T28 Circum-Arctic Structural Events: Tectonic Evolution of the Arctic Margins and Trans-Arctic Links with Adjacent Orogens

Sunday, 22 October 2017
8:00 AM - 12:00 PM
Tahoma 3

TECTONICS OF THE NORTHERN PART OF VERKHOYANSK AND OLENEK FOLD BELTS: IMPLICATION FOR LATE MESOZOIC – EARLY CENOZOIC EVOLUTION OF LAPTEV SEA REGION

Paper number: T28-15
Program: Technical Sessions
Time: 11:30 AM – 11:45 AM

Authors

Abstract

The study area located along the margin of Siberian Craton and includes northern part of Verkoyansk and Olenek Fold belts, Lena-Anabar depression and Priverkhoyansk foreland basin. The N trend Verkhoyansk FB formed as a result of Late Mesozoic collision between Siberia and Kolyma-Omolon super terrane and comprises deformed Jurassic to Mesoproterozoic rocks. Modern structural style of the Verkhoyansk FB was formed by Cretaceous orogeny and it is caused subsidence in the Priverkhoyansk foreland basin where occurrence of a buried thrust front with triangle zones. Based on detailed field studies and AFT analyses several stages of Cretaceous compressional deformation have been deciphered. The abrupt transition from marine to fluvial sedimentation that occurred across Preverkhoyansk foreland in Early Valanginian marked the oldest orogenic event in the adjust Verkhoyansk FB. The main stage of deformation marked by the first two generations of D1 и D2 folds and major displacements inferred from AFT data as Albian to Santonian in age. In the northern Verkhoyansk FB N-trending folds are deformed by NW-trending folds with strike is the same as in the Olenek FB. Accordingly AFT data this event occurred in the Campanian–Paleocene. The latest structures observed within Northern part Of Verkhoyansk FB are several mainly N-trending grabens filled in with Cenozoic sediments. The structural stiles of Olenek FB is simple with predominance of 10-15 km wide folds with rare large thrusts, cleavage is absent. AFT data obtained from the Olenek FB exhibit to uplifts that occurred in Aptian-Albian and Maastrichtian-Paleocene. Accordingly structural studies the latter is better expressed and could be interpreted as the main deformation event. Post-Paleocene evolution of Olenek FB is mostly characterized by fracturing and normal faulting. Thus, the southern part of Laptev Sea region are characterized by Late Early Cretaceous Verkhoyansk Orogeny and superimposed by Maastrichtian-Paleocene contractional deformation of Olenek FB and complicated by Paleocene-Eocene extension.

The study was partly supported by TGS-NEOPEC Geophysical Company and RSF grants 17-17-01171.

Geological Society of America Abstracts with Programs. Vol. 49, No. 6

doi: 10.1130/abs/2017AM-295939

© Copyright 2017 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.