Tipo
Artigos em Revista
Tipo de Documento
Artigo Completo
Título
Morphotectonics in a low tectonic rate area: Analysis of the southern Portuguese Atlantic coastal region
Participantes na publicação
Paula M. Figueiredo (Author)
Thomas K. Rockwell (Author)
João Cabral (Author)
Dep. Geologia
IDL
Cristina Ponte Lira (Author)
Dep. Geologia
IDL
Resumo
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); however, the mechanisms that drive this uplift are poorly understood. 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 V f , basin asymmetry factor AF, hypsometry HI and, the stream-length gradient index SL, and we propose the terminal basin shape index TBS. This study aims to (1) identify Quaternary deformation along presumed tectonic structures; (2) recognize uplift or subsidence along the coastline; 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, even for low vertical motion rates, whereas other indices were found to be not as sensitive to variations in uplift rate.
Data de Submissão/Pedido
2017-07-03
Data de Aceitação
2018-02-14
Data de Publicação
2019-02
Instituição
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA
Suporte
Geomorphology
Identificadores da Publicação
ISSN - 0169-555X
Editora
Elsevier BV
Número de Páginas
19
Página Inicial
132
Página Final
151
Identificadores do Documento
DOI -
https://doi.org/10.1016/j.geomorph.2018.02.019
URL -
http://dx.doi.org/10.1016/j.geomorph.2018.02.019
Identificadores de Qualidade
SCIMAGO Q1 (2019) - 1.384 - Earth-Surface Processes
SCOPUS Q1 (2019) - 6.9 - Earth-Surface Processes
Web Of Science Q1 (2019) - 3.819 - GEOSCIENCES, MULTIDISCIPLINARY - SCIE
Web Of Science Q1 (2019) - 3.819 - GEOGRAPHY PHYSICAL - SCIE
Keywords
Portugal
Uplift
Morphotectonic analysis
Low tectonic rate