Field reconnaissance of the Anti-Atlas coastline, Morocco: Fluvial and marine evidence for Late Cenozoic uplift


WESTAWAY R., HSSAINE A. A., Demir T., Beck A.

GLOBAL AND PLANETARY CHANGE, cilt.68, sa.4, ss.297-310, 2009 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 68 Sayı: 4
  • Basım Tarihi: 2009
  • Doi Numarası: 10.1016/j.gloplacha.2009.03.016
  • Dergi Adı: GLOBAL AND PLANETARY CHANGE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.297-310
  • Anahtar Kelimeler: Morocco, Anti-Atlas, Pliocene, Pleistocene, uplift, fluvial terraces, marine terraces, LOWER CONTINENTAL-CRUST, SURFACE PROCESSES, QUATERNARY EVOLUTION, PLEISTOCENE RIVER, WESTERN TURKEY, SOUSS BASIN, FLOW, PLIOCENE, TECTONICS, OPHIOLITE
  • Akdeniz Üniversitesi Adresli: Hayır

Özet

The available evidence regarding the disposition and chronology of Pliocene-Pleistocene fluvial terraces, coastal rock flats, raised beaches and lacustrine sediments adjoining the Anti-Atlas coastline of Morocco has been reviewed and supplemented by additional information from our own field reconnaissance. It is thus suggested that the study region has experienced uplift by similar to 130 m since the Mid-Pliocene climatic optimum (similar to 3.1 Ma), by similar to 90 m since the latest Pliocene (similar to 2 Ma), and by similar to 45 m since the Mid-Pleistocene Revolution (similar to 0.9 Ma). Each of these phases of uplift correlates with a phase of global climate change known independently, and it is thus inferred that the observed uplift is being driven by climate through mechanisms such as erosional isostasy and the associated induced lower-crustal flow. Numerical modelling of the observed uplift history indicates that the mobile lower-crustal layer in the study region is similar to 9 km thick, with a temperature at its base of similar to 500 degrees C. The base of this mobile layer is inferred to be at similar to 24 km depth, the deepest crust consisting of a layer of mafic underplating that does not flow under ambient conditions. The principal landform in the study region, the coastal rock platform at similar to 60 m a.s.l., thus formed during a succession of interglacial marine highstands in the late Early Pleistocene when uplift rates were low. Although control on the ages of young sediments and landforms is currently extremely limited, being dependent on regional correlation schemes rather than on absolute dating, the study region fits the pattern, emerging worldwide, that climate change is driving the systematic growth of topographic relief evident during the Late Cenozoic. (C) 2009 Elsevier B.V. All rights reserved.