Syntectonic Intraformational Unconformities in Alluvial Fan Deposits, Eastern Ebro Basin Margins (NE Spain)

  1. P. A. Allen and
  2. P. Homewood
  1. Pere Anadón1,
  2. Lluís Cabrera2,
  3. Ferran Colombo2,
  4. Mariano Marzo2 and
  5. Oriol Riba2

Published Online: 5 MAY 2009

DOI: 10.1002/9781444303810.ch14

Foreland Basins

Foreland Basins

How to Cite

Anadón, P., Cabrera, L., Colombo, F., Marzo, M. and Riba, O. (1986) Syntectonic Intraformational Unconformities in Alluvial Fan Deposits, Eastern Ebro Basin Margins (NE Spain), in Foreland Basins (eds P. A. Allen and P. Homewood), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303810.ch14

Author Information

  1. 1

    Institut Jaume Almera, C.S.I.C. (Barcelona), Martí Franques s/n. 08028 Barcelona, Spain

  2. 2

    Department d'Estratigrafia, Universitat de Barcelona, Gran Via, 585, 08007 Barcelona, Spain

Publication History

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

ISBN Information

Print ISBN: 9780632017324

Online ISBN: 9781444303810



  • syntectonic intraformational unconformities in alluvial fan deposits, eastern Ebro Basin margins (NE Spain);
  • progressive syntectonic unconformities showing similar geometric features;
  • tectonics and sedimentation during Palaeogene at eastern Ebro Basin margins;
  • progressive and angular syntectonic unconformities;
  • syntectonic unconformities related to thrust sheet emplacement (south-eastern Pyrenean front);
  • syntectonic unconformities related to uplifting blocks (Catalan coastal range);
  • Map pattern of Sant Miquel del Montclar conglomerates;
  • stratigraphy and structure of tertiary deposits in AUoza-Andorra area;
  • diachroneity and evaluating nappe movements


Several types of syntectonic intraformational unconformities can be observed in the Palaeogene alluvial fan conglomerates deposited in the eastern Ebro Basin margins. Progressive unconformities are the most common but unconformities displayed by supratenuous folds are also observed. We describe syntectonic intraformational unconformities related to the following structural settings: (a) Nappe fronts (i.e. Cadí Nappe in the southern Pyrenees). Development and deformation of the progressive unconformities are related to successive movements during the late phases of floor thrust emergence. (b) Uplifting structures related to the basement-involved strike-slip fault system of the Catalan Coastal Range: monoclinal folds linked to uplifting blocks and stretched cover folds. The successive motion of basement faults located more and more basinward resulted in a shifting of the basin boundary in some sectors. Syntectonic intraformational unconformities developed in the alluvial fan sequences which accumulated along each new basin boundary. (c) Folds affecting a thick Mesozoic cover (Linking Zone). In this case, folding during sedimentation produced progressive unconformities in the Tertiary strata at the fold limbs. Supratenuous synclines affecting the Tertiary syntectonic deposits developed between the anticlines.

Progressive syntectonic unconformities recognized in the structural settings mentioned above show broadly similar geometric features. The syntectonic intraformational unconformities are related to uplifting structures such as nappe fronts, monoclinal folds, overfolds and limited overthrusts. The spatial and temporal distribution of the syntectonic intraformational unconformities record the diachronous development of these structures along the margins of the eastern Ebro Basin.