부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.geomorph.2007.06.022 Byline: Inmaculada Menendez (a), Pablo G. Silva (b), Moises Martin-Betancor (c), Francisco Jose Perez-Torrado (a), Herve Guillou (d), S. Scaillet (d) Keywords: Fluvial incision; Isostatic uplift; Geophysical relief; Volcanic islands; Gran Canaria; Canary Islands Abstract: Digital analysis of torrential gullies ('barrancos') deeply incised into the volcanic Island of Gran Canaria (Canary Islands) allows us to extract the longitudinal profiles and pre-incision surfaces for individual basins, from which morphometric parameters (length, elevation, area, slope) have been calculated. Other derived parameters, such as ridgeline profiles, maximum incision values, volume removed by fluvial erosion, geophysical relief and isostatic uplift, have also been computed. Based on K/Ar ages for the island, well-constrained incision-uplift rates have been calculated by means of the combination of different methodological approaches commonly used in orogens and large mountain ranges. The geomorphological and morphometric analyses reveal that the island is clearly divided into four environmental quadrants determined by the combination of a couple of key-factors: the age of the volcanic surfaces and the climatic conditions. These factors determine a young sector covered with Plio-Quaternary platform-forming lavas (finished at 1.9-1.5 Ma) evolving under contrasting wet (NE) to dry (SE) climates, and an older sector, conserving the residual surfaces of the Miocene shield building (14.5-8.7 Ma) at the ridgelines, also subjected to wet (NW) and dry (SW) climates. Incision is related to the age zonation of the island. Maximum incisions ( Author Affiliation: (a) Departamento de Fisica, Facultad de Ciencias del Mar, Universidad de Las Palmas de Gran Canaria, Campus Universitario Tafira Baja, 35017, Las Palmas de Gran Canaria, Spain (b) Departamento de Geologia, Universidad de Salamanca, Escuela Politecnica Superior de Avila, Avda. Hornos Caleros, 50, 05003 Avila, Spain (c) Departamento de Cartografia y Expresion Grafica en Ingenieria, Edificio Ingenierias, Universidad de Las Palmas de Gran Canaria, Campus Universitario Tafira Baja, 35017, Las Palmas de Gran Canaria, Spain (d) Laboratorio des Sciences du Climat et de l'Environonement, CEA-CNRS, LSCE-Valle, BAcentst. 12, F-91198 Gif-sur-Yvette, France Article History: Received 11 January 2006; Revised 6 March 2007; Accepted 5 June 2007