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Publication details

Document type
Conference papers

Document subtype
Extended abstract/Short paper

Title
Morphotectonic analysis of the southern Portuguese Atlantic coastal zone – implications for active tectonics

Participants in the publication
Figueiredo, P.M. (Author)
Rockwell, T.K. (Author)
Cabral, J. (Author)
Dep. Geologia
 IDL
 Ponte Lira, C. (Author)
Dep. Geologia
 IDL
Summary
The south Portugal is characterized by low tectonic rates (<0.3 mm/a), with infrequent large seismicity. Recent studies indicate a coastal region in southwest Portugal uplifting at higher rates (0.11 ± 0.01 mm/a) than the remaining southern portion of Portugal (~0.04 mm/a). The mechanisms responsible for the higher uplift are poorly understood, as well as the pattern of the increase in vertical motion and its exact location. In addition, some structures are associated with relevant morphology but their degree of Quaternary tectonic activity is also poorly constrained. Thus, with the purpose of investigating the regional Quaternary deformation and its patterns, as well as the difference in the uplift rate, 77 exorheic drainage basins along 460 km of the southern Portuguese coastline were analysed through the application of geomorphic indices. In this study we applied stream channel sinuosity S, basin relief ratio Rh, elongation Re, basin shape ratio Bs, valley height-width ratio Vf, basin asymmetry factor AF, hypsometry HI and, the stream-length gradient index SL, and we propose the terminal basin shape index TBS. Our aims are\\\\nmainly to (1) identify Quaternary deformation along presumed tectonic structures; (2) recognize uplift or subsidence along the\\\\ncoastline; and (3) test the application of geomorphic indices in low deformation rate environments. The cross-correlation of results led to the recognition of the São Teotónio-Aljezur-Sinceira fault system and the São Marcos-Quarteira Fault as major regional Quaternary faults, as well as to the interpretation of Quaternary activity for other structures. Spatial differences in uplift rates are identified through basin shape indices and valley height-width ratios, corroborating the recent studies. Altogether, results also demonstrate the applicability of some morphotectonic indices, even for low vertical motion rates.

Editor(s)
C. Canora, F. Martín, E. Massana, R. Pérez y M. Ortuño

Date of Publication
2018-06-11

Institution
Universidad de Alicante

Event
Tercera reunión ibérica sobre fallas activas y paleosismología (Iberfault 2018 (Resúmenes), 11-13 junio de 2018, Alicante, España

Publication Identifiers
ISBN - 9788409024735

Address
Alicante, Espanha

Number of pages
4
Starting page
39
Last page
42


Export

APA
Figueiredo, P.M., Rockwell, T.K., Cabral, J., Ponte Lira, C., (2018). Morphotectonic analysis of the southern Portuguese Atlantic coastal zone – implications for active tectonics. Tercera reunión ibérica sobre fallas activas y paleosismología (Iberfault 2018 (Resúmenes), 11-13 junio de 2018, Alicante, España, 39-42

IEEE
Figueiredo, P.M., Rockwell, T.K., Cabral, J., Ponte Lira, C., "Morphotectonic analysis of the southern Portuguese Atlantic coastal zone – implications for active tectonics" in Tercera reunión ibérica sobre fallas activas y paleosismología (Iberfault 2018 (Resúmenes), 11-13 junio de 2018, Alicante, España, Alicante, Espanha, 2018, pp. 39-42, doi:

BIBTEX
@InProceedings{40826, author = {Figueiredo, P.M. and Rockwell, T.K. and Cabral, J. and Ponte Lira, C.}, title = {Morphotectonic analysis of the southern Portuguese Atlantic coastal zone – implications for active tectonics}, booktitle = {Tercera reunión ibérica sobre fallas activas y paleosismología (Iberfault 2018 (Resúmenes), 11-13 junio de 2018, Alicante, España}, year = 2018, pages = {39-42}, address = {Alicante, Espanha}, publisher = {} }