Show simple item record Neil F. en_US Matias C. en_US 2010-12-15T10:52:55Z 2010-12-15T10:52:55Z 2009-04-15 en_US
dc.identifier en_US
dc.identifier.citation Glasser , N F & Ghiglione , M C 2009 , ' Structural, tectonic and glaciological controls on the evolution of fjord landscapes ' Geomorphology , vol 105 , no. 3-4 , pp. 291-302 . , 10.1016/j.geomorph.2008.10.007 en_US
dc.identifier.other PURE: 155472 en_US
dc.identifier.other dspace: 2160/6009 en_US
dc.description.abstract The fjord landscape of South America, stretching ~ 1500 km between Golfo Corcovado (~ 43°S) and Tierra del Fuego (~ 56°S), is the largest continuous fjord landscape on Earth. This paper presents the results of new structural geological and geomorphological mapping of this landscape using optical satellite images and digital elevation models. First-order geological structures are represented by strike-slip faults forming lineaments up to hundreds of kilometres long. The strike-slip faulting has been active since Late Cretaceous times and is responsible for the presence of a conspicuous structural cleavage visible as lineaments up to ~ 10 km long. A detailed analysis of these second-order lineaments from digital image data was carried out in three sectors. In Sector 1, located northwest of the North Patagonian Icefield, there are three distinct mean orientations, characterized by a main nearly orogen-parallel orientation (az. ~ 145°) and two orogen-oblique secondary orientations (az. ~ 20° and az. ~ 65°). In Sector 2, located west of the South Patagonian Icefield, there are also three separate mean orientations, with most of the lineaments concentrated between azimuths 0° and 80° (mean at ~ 36°); and two other orogen-oblique means at azimuth ~ 122° and ~ 163°. In Sector 3, around the Cordillera Darwin, there is a single main orogen-parallel mean at ~ 100–115°. In all three sectors, mapped fjord orientations bear a striking similarity to the structural data, with fjords orientated preferentially in the same direction as structural lineaments. We infer that successive glaciations followed the same ice-discharge routes, widening and deepening pre-existing geological structures at the expense of the surrounding terrain to create the fjord landscape. This study has broader implications for ice sheet reconstructions and landscape evolution beneath ice sheets because we demonstrate that the primary control on fjord development in glaciated areas is geological and not glaciological. en_US
dc.format.extent 12 en_US
dc.relation.ispartof Geomorphology en_US
dc.subject fjords en_US
dc.subject South America en_US
dc.subject Patagonia en_US
dc.subject structural geology en_US
dc.subject tectonics en_US
dc.subject glacial geomorphology en_US
dc.title Structural, tectonic and glaciological controls on the evolution of fjord landscapes en_US
dc.contributor.pbl Institute of Geography & Earth Sciences en_US
dc.contributor.pbl Centre for Glaciology en_US

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