About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract

AAPG Bulletin, V. 106, No. 1 (January 2022), P. 21-41.

Copyright ©2022. The American Association of Petroleum Geologists. All rights reserved.

DOI: 10.1306/04212118218

The effects of initial wedge taper on area-balancing restoration of a fold-thrust belt

Xiaodong Yang,1 David J. Sanderson,2 Lisa C. McNeill,3 and Frank J. Peel4

1Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China; [email protected]
2Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, United Kingdom; [email protected]
3Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, United Kingdom; [email protected]
4Applied Geodynamic Laboratory, Bureau of Economic Geology, The University of Texas at Austin, Austin, Texas; [email protected]

ABSTRACT

The conventional area-balancing method uses a single regional slope, commonly parallel to basal detachment and generally horizontal, to restore a deformed geological section to an initial rectangular shape. However, most fold-thrust belts exhibit a wedge or trapezium (i.e., a quadrilateral with at least one pair of parallel sides) shape in cross section with stratigraphic sequence thinning into the basin. Two new, simple, quantitative solutions are developed to restore a thrust belt with more realistic geometries, which assume that the initial shape is a trapezium. This allows exploration of the function of initial wedge taper (represented by surface slope and basal dip) in controlling shortening estimate using area balancing. The new methods are tested against sandbox models and natural examples of fold-thrust belts using a range of input parameters to evaluate the uncertainties in shortening calculation. We find the results are very sensitive to both initial surface slope and initial basal slope. This study highlights the significance of initial wedge taper in determining shortening across a fold-thrust belt, with accurate shortening estimates requiring independent constraint of this important geometry. Previous studies that used area balancing to predict depth to detachment and/or to estimate shortening without considering the effects of initial wedge taper may need reevaluation.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24

AAPG Member?

Please login with your Member username and password.

Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].