Publication Date:
2020-11-30
Description:
The growth of faults and folds in basins formed under transtension has been less studied than in their extensional counterparts. In this study, we capitalise on 3D seismic reflection data to investigate the evolution of faults and folds that evolved coevally during sub-orthogonal partitioned extension and shortening, respectively, in the Sørvestsnaget Basin, Western Barents Sea. We use quantitative techniques to constrain the distribution of normal fault throw, shortening accommodated by folds and thrusts, and stratigraphic thickness variations, to analyse the relative temporal and spatial evolution of faults and folds. Our results show that normal faults display a similar evolution to those occurring in extensional basins, where they grew by lateral- and dip-linkage of individual fault segments as well as upward propagation. Notably, we show that shortening-related fold growth affected the fault growth patterns, skewing their throw distributions, and shifting the location of accommodation away from the evolving folds. Thus, fold amplification caused lateral migration of normal fault hanging-wall depocentres. Our results shed new light on fault and fold growth processes in transtensional basins and contributes to an improved understanding of the structural evolution of basins forming along sheared continental margins, which has economic implications for sheared-margin basins targeted for hydrocarbon exploration.
Print ISSN:
0305-8719
Electronic ISSN:
2041-4927
Topics:
Geosciences
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