Thrust Tectonic Controls on Miocene Alluvial Distribution Patterns, Southern Pyrenees

  1. P. A. Allen and
  2. P. Homewood
  1. J. P. P. Hirst1 and
  2. G. J. Nichols2

Published Online: 5 MAY 2009

DOI: 10.1002/9781444303810.ch13

Foreland Basins

Foreland Basins

How to Cite

Hirst, J. P. P. and Nichols, G. J. (1986) Thrust Tectonic Controls on Miocene Alluvial Distribution Patterns, Southern Pyrenees, in Foreland Basins (eds P. A. Allen and P. Homewood), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303810.ch13

Author Information

  1. 1

    B.P. Petroleum Development Ltd, Kirklington Road, Eakring, Newark NG22 0DA, UK

  2. 2

    Department of Geological Sciences, University of Liverpool, P.O. Box 147, Liverpool L69 3BX, UK

Publication History

  1. Published Online: 5 MAY 2009
  2. Published Print: 22 DEC 1986

ISBN Information

Print ISBN: 9780632017324

Online ISBN: 9781444303810

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Keywords:

  • thrust tectonic controls on Miocene alluvial distribution patterns, southern Pyrenees;
  • alluvial dispersal patterns in northern Ebro Basin, southern foredeep of Pyrenees;
  • fluvial distributary systems;
  • principal Lower Miocene alluvial fan deposits along northern margin of Ebro Basin in study area;
  • deposits of Luna System;
  • lacustrine zone interdigitating with both of fluvial systems;
  • structural controls on sedimentation patterns;
  • Miocene southern Pyrenees and modern Himalayants and Mesozoic-Tertiary Canadian Cordillera

Summary

Alluvial dispersal patterns in the northern Ebro Basin, the southern foredeep of the Pyrenees, can be shown to be controlled by the positions of frontal and lateral ramps in the adjacent southern Pyrenean thrust belt. The apices of two early Miocene fluvial distributary systems in the north-western part of the Ebro Basin lie in front of structural lows. Detrital mineral suites in these distributary systems indicate that the drainage basins of these systems included the axial zone of the Pyrenees. Along the 100 km between the apices of the two systems the frontal ramp of the thrust sheet was developed as a structural salient, forming a barrier to the headward migration of streams during the early Miocene. A series of relatively small alluvial fans formed along this part of the basin margin at the topographic break between the frontal ramp and the Ebro Basin: analysis of the clast types present in these fans shows that their drainage basins lay within the topographic high of the thrust front.

It is suggested that the patterns observed in the northern Ebro Basin—fan-shaped fluvial distributary systems, the apices of which lie at structural lows in the basin margin, plus smaller alluvial fans along the higher parts of the margin—may be characteristic of foreland basins with internal drainage. The geometry of the thrust sheets in the adjacent thrust belt controls these alluvial distribution patterns.