Subsidence Rates and Fluvial Architecture of Rift-Related Permian and Triassic Alluvial Sediments of the Southeast Iberian Range, Eastern Spain

  1. N. D. Smith2 and
  2. J. Rogers3
  1. A. Arche and
  2. J. López-Gómez

Published Online: 17 MAR 2009

DOI: 10.1002/9781444304213.ch21

Fluvial Sedimentology VI

Fluvial Sedimentology VI

How to Cite

Arche, A. and López-Gómez, J. (1999) Subsidence Rates and Fluvial Architecture of Rift-Related Permian and Triassic Alluvial Sediments of the Southeast Iberian Range, Eastern Spain, in Fluvial Sedimentology VI (eds N. D. Smith and J. Rogers), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444304213.ch21

Editor Information

  1. 2

    Department of Geosciences, 214 Bessey Hall, University of Nebraska, Lincoln, NE 68588-0340, USA

  2. 3

    Cape Town, South Africa

Author Information

  1. Instituto de Geología Económica – Departamento de Estratigrafía, CSIC-UCM, Facultad de Geología, Universidad Complutense, 28040 Madrid, Spain

Publication History

  1. Published Online: 17 MAR 2009
  2. Published Print: 7 OCT 1999

ISBN Information

Print ISBN: 9780632053544

Online ISBN: 9781444304213

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Keywords:

  • subsidence rates and fluvial architecture of rift-related Permian and Triassic;
  • Iberian Basin - extensional rift basin in east central Spain;
  • Permian and Triassic alluvial sediments of Iberian Range;
  • stratigraphical succession under investigation corresponding to first stage in Permian–Triassic evolution of Iberian Basin;
  • tectonic evolution of Iberian basin - Permian and Triassic periods;
  • fluvial architecture and fluvial style;
  • tectonic control of fluvial architecture

Summary

The Iberian Basin is an extensional rift basin in east central Spain that dates back to the Early Permian, but which underwent complex development during the Mesozoic and Cenozoic. The earliest sedimentary infill consists of alluvial deposits subdivided into three unconformity-bounded macrosequences of Early Permian, Late Permian and Early Triassic ages. The interplay of subsidence rate changes, sediment supply and regional gradient controlled fluvial styles, channel geometry and vertical stacking of sequences. Subsidence rates have changed over time by a factor of 35, depending on basin boundary-fault activity and multiphase extensional processes. Palaeocurrent changes reflect regional gradient changes, and sediment supply changed considerably from the early stages of infill, which were dominated by transverse transport from local sources, to the later stages, which were dominated by longitudinal transport from distal sources.

Relative sea-level changes did not affect the two early macrosequences deposited in interior drainage basins, but they may have affected the upper part of the third macrosequence deposited during a lowstand to transgressive period. Climatic changes are very difficult to discern, but a general trend from wet, seasonal climates to more arid conditions is suggested by palaeontological and sedimentological evidence. Subsidence curves are presented and related to the ratios of channel/overbank deposits, avulsion rates and the degree of amalgamation of channel deposits in each macrosequence. Periods of fast subsidence are characterized by isolated channels and predominance of overbank deposits, whereas periods of slow subsidence show lateral accretion channel deposits, scarce overbank deposits and amalgamation of channel sandstone bodies.