Structural, tectonic and glaciological controls on the evolution of fjord landscapes

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dc.contributor.author Ghiglione, Matias C.
dc.contributor.author Glasser, Neil F.
dc.date.accessioned 2010-12-15T10:52:55Z
dc.date.available 2010-12-15T10:52:55Z
dc.date.issued 2009-04-15
dc.identifier.citation Ghiglione , M C & Glasser , N F 2009 , ' Structural, tectonic and glaciological controls on the evolution of fjord landscapes ' Geomorphology , vol 105 , pp. 291-302 . en
dc.identifier.other PURE: 155472
dc.identifier.other dspace: 2160/6009
dc.identifier.uri http://hdl.handle.net/2160/6009
dc.description Glasser, N. F., Ghiglione, M. C. (2009). Structural, tectonic and glaciological controls on the evolution of fjord landscapes. Geomorphology, 105 (3/4): 291-302. en
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
dc.format.extent 12 en
dc.language.iso eng
dc.relation.ispartof Geomorphology en
dc.title Structural, tectonic and glaciological controls on the evolution of fjord landscapes en
dc.type Text en
dc.type.publicationtype Article (Journal) en
dc.identifier.doi http://dx.doi.org/10.1016/j.geomorph.2008.10.007
dc.contributor.institution Institute of Geography & Earth Sciences en
dc.contributor.institution Centre for Glaciology en
dc.description.status Peer reviewed en


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