Quaternary siliciclastic sequence stratigraphy of western Mediterranean passive and tectonically active margins: the role of global versus local controlling factors
Ercilla, G.; Alonso, B. (1996). Quaternary siliciclastic sequence stratigraphy of western Mediterranean passive and tectonically active margins: the role of global versus local controlling factors, in: De Batist, M. et al. Geology of siliciclastic shelf seas. Geological Society Special Publication, 117: pp. 125-137 In: De Batist, M.; Jacobs, P. (Ed.) (1996). Geology of siliciclastic shelf seas. Geological Society Special Publication, 117. The Geological Society (London): London. ISBN 1-897799-67-5. 345 pp., more In: Hartley, A.J. et al. (Ed.) Geological Society Special Publication. Geological Society of London: Oxford; London; Edinburgh; Boston, Mass.; Carlton, Vic.. ISSN 0305-8719; e-ISSN 2041-4927, more |
| Abstract | A study of the Quaternary sequence stratigraphy of two siliciclastic Spanish Mediterranean margins with a different geological setting was carried out. This study reveals that the Quaternary stratigraphical architectures of the northern Catalonia passive continental margin and of the northwestern Alboran tectonically active margin are mainly characterized by the stacking of high-frequency lowstand systems tracts. Only the Versilian transgressive and Holocene highstand systems tracts have been recognized. This kind of stratigraphical architecture is the product of the eustatic cyclicity characterized by sea-level changes of high frequency, high amplitude and marked asymmetry, regardless of local geological context. On the other hand, local factors seem to play an important role in the stratal pattern, its preservation and sedimentary distribution. Thus, tectonics was responsible for strong lateral variations in margin growth pattern, changing from progradational to divergent in the tectonically active margin of the northwestern Alboran. Tectonics also conditioned the preservation of the lowstand systems tracts along and through the margin: the lowstand systems tracts are preserved from shelf in subsiding areas, e.g. northern Catalonia and the central sector of the northwestem Alboran, and from slope in uplifting areas, e.g. eastern and western sectors of the northwestern Alboran. Physiography conditioned the acrossmargin location of sedimentary depocentres: on the outer shelf and upper slope, when the shelf is relatively wide as occurs in northern Catalonia, and on the base-of-slope when the shelf is relatively narrow as occurs in the northwestem Alboran. Variations in the volume of sediment supply conditioned the along-margin location of sedimentary depocentres, which changed from south to north in northern Catalonia. |
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