Stacked Gilbert-Type Deltas in the Marine Pull-Apart Basin of Abarán, Late Serravallian—Early Tortonian, Southeastern Spain
- Albina Colella2 and
- David B. Prior3
Published Online: 2 APR 2009
Copyright © 1990 The International Association of Sedimentologists
How to Cite
van der Straaten, H. C. (1990) Stacked Gilbert-Type Deltas in the Marine Pull-Apart Basin of Abarán, Late Serravallian—Early Tortonian, Southeastern Spain, in Coarse-Grained Deltas (eds A. Colella and D. B. Prior), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303858.ch11
Universita della Calabria, Italy
Atlantic Geoscience Center, Nova Scotia, Canada
- Published Online: 2 APR 2009
- Published Print: 19 OCT 1990
Print ISBN: 9780632028948
Online ISBN: 9781444303858
- Abaran pull-apart basin;
- Gilbert-type delta complex, representing axial fill;
- gastropods, resembling Cerithium sp;
- major axial deltaic systems and minor lateral talus systems, controlling facies distribution;
- sedimentary record of Abaran Basin, revealing upward-fining and deepening trend
The Abarán Basin is a marine pull-apart basin that developed inside a releasing overstep along a right-slip fault zone. Due to progressive opening of the basin, extension in a direction parallel to the major strike-slip faults prevailed throughout the sedimentary history. Periods of filling were followed by faulting episodes leading to periodic deepening. Tectonic subsidence controlled the development of three depositional sequences bounded by angular unconformities. Each sequence reflects a major axial system of predominantly sand-sized deltaic sediments and a minor lateral system comprising a series of gravelly fault- and reef-taluses that rim the basin.
A Gilbert-type delta complex formed the axial system of the oldest sequence. It consists of deltas stacked in an imbricate way which are separated from each other by inclined truncational surfaces interpreted as major slide scars. The threefold division in top-, fore- and bottomsets typical for Gilbert-type deltas, is recognized. Foresets, dipping about 20° W and SW, asymptotically pass into more gently inclined bottomsets. Locally, subhorizontal, shallow-marine topsets, modified by wave action, truncate the underlying foresets.
The extensional regime during the development of the delta complex is illustrated by a prominent deepening and the activity of normal faults. Progressively deeper water is deduced from the height of the delta foresets increasing from 30 m to more than 150 m. NNW-trending normal faults express extension in a direction parallel to the major E—W strike-slip fault zone and fit in the structural concept of the pull-apart basin. They dip away from the basin centre and migrate progressively basinwards. Normal faulting is considered to have controlled the imbricate stacking of the deltas.