Glacigenic features and Tertiary stratigraphy of the Magellan Strait (Southern Chile)
The seismostratigraphic and structural analysis of the whole length of the Magellan Strait, from the Atlantic to the Pacific entrance is for first time illustrated on the basis of multichannel seismic (MCS) profiles. The Strait crosses a geologically complex region that includes different morphotect...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Universitat de Barcelona (UB), Geociències Barcelona (Geo3BCN), Institut de Diagnosi Ambiental i Estudis de l'Aigua (IDAEA), Universitat Autònoma de Barcelona (UAB)
2008-03-01
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| Series: | Geologica Acta |
| Subjects: | |
| Online Access: | https://revistes.ub.edu/index.php/GEOACTA/article/view/1922 |
| _version_ | 1797654621177511936 |
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| author | R. BARTOLE S. DE MURO D. MORELLI F. TOSORATTI |
| author_facet | R. BARTOLE S. DE MURO D. MORELLI F. TOSORATTI |
| author_sort | R. BARTOLE |
| collection | DOAJ |
| description | The seismostratigraphic and structural analysis of the whole length of the Magellan Strait, from the Atlantic to the Pacific entrance is for first time illustrated on the basis of multichannel seismic (MCS) profiles. The Strait crosses a geologically complex region that includes different morphotectonic provinces, and has been subdivided into three distinct segments, eastern (Atlantic), central, and western (Pacific), being each segment characterized by peculiar sedimentary and tectonic architectures. The MCS profiles shed light on the subsurface of the region in particular on the Quaternary and Tertiary features. In the foreland basin province, the MCS profiles imaged an almost undeformed structural and stratigraphic frame with very thick Cretaceous to Tertiary package. Seismic evidence of deformation of the foreland units occurs in the fold-and-thrust belt province. Along the Cordillera province, the Magallanes-Fagnano transform fault exerts an important morpho-tectonic control that strongly conditions its bathymetric profile. The seismic profiles also highlighted a number of depositional features linked to the up to 150 m thick sedimentary record of the glacial cycles. Whereas the eastern segment (outer foreland province) is devoid of significant glacial-related deposits, the central segment (inner foreland and fold-and thrust belt provinces) shows evidence of repeated advances and retreats of the Magellan glacier. An important moraine ridge complex, probably corresponding to the glacial advance “D”of Clapperton et al., has been seismically imaged in the central segment, as well as an older, large bank of ice distal sediments that have been interpreted as proglacial lake deposits, which show evident signs of repeated glacial erosions. Ice-contact features in the form of frontal moraine complexes made up of dipping foreset strata are present in the fjord-like, western segment of the Strait (Cordillera province), along with their related ice-proximal and ice-distal facies. Eventually, the occurrence of preglacial sediments tectonized by the Magallanes-Fagnano transform fault has been reported in the same segment. This fact, which is supported by small outcrops reported in the updated geologic map, if substantiated by further investigations (i.e. advanced seismic reprocessing, sea bottom samplings), would prove the relatively young age (Late Miocene?) of the Magallanes-Fagnano transform fault. |
| first_indexed | 2024-03-11T17:02:10Z |
| format | Article |
| id | doaj.art-52dcbfe154d54e988dca90db9c052698 |
| institution | Directory Open Access Journal |
| issn | 1696-5728 |
| language | English |
| last_indexed | 2024-03-11T17:02:10Z |
| publishDate | 2008-03-01 |
| publisher | Universitat de Barcelona (UB), Geociències Barcelona (Geo3BCN), Institut de Diagnosi Ambiental i Estudis de l'Aigua (IDAEA), Universitat Autònoma de Barcelona (UAB) |
| record_format | Article |
| series | Geologica Acta |
| spelling | doaj.art-52dcbfe154d54e988dca90db9c0526982023-10-20T07:14:13ZengUniversitat de Barcelona (UB), Geociències Barcelona (Geo3BCN), Institut de Diagnosi Ambiental i Estudis de l'Aigua (IDAEA), Universitat Autònoma de Barcelona (UAB)Geologica Acta1696-57282008-03-016110.1344/105.000000243Glacigenic features and Tertiary stratigraphy of the Magellan Strait (Southern Chile)R. BARTOLE0S. DE MURO1D. MORELLI2F. TOSORATTI3Dipartimento di Scienze Geologiche Ambientali e Marine, Univ. degli Studi di TriesteVia E. Weiss 2, 34127 Trieste – Italy.Dipartimento di Scienze della Terra, Univ. degli Studi di CagliariVia Trentino 51, 09127 Cagliari – Italy.Dipartimento di Scienze Geologiche Ambientali e Marine, Univ. degli Studi di TriesteVia E. Weiss 2, 34127 Trieste – Italy.Dipartimento di Scienze Geologiche Ambientali e Marine, Univ. degli Studi di TriesteVia E. Weiss 2, 34127 Trieste – Italy.The seismostratigraphic and structural analysis of the whole length of the Magellan Strait, from the Atlantic to the Pacific entrance is for first time illustrated on the basis of multichannel seismic (MCS) profiles. The Strait crosses a geologically complex region that includes different morphotectonic provinces, and has been subdivided into three distinct segments, eastern (Atlantic), central, and western (Pacific), being each segment characterized by peculiar sedimentary and tectonic architectures. The MCS profiles shed light on the subsurface of the region in particular on the Quaternary and Tertiary features. In the foreland basin province, the MCS profiles imaged an almost undeformed structural and stratigraphic frame with very thick Cretaceous to Tertiary package. Seismic evidence of deformation of the foreland units occurs in the fold-and-thrust belt province. Along the Cordillera province, the Magallanes-Fagnano transform fault exerts an important morpho-tectonic control that strongly conditions its bathymetric profile. The seismic profiles also highlighted a number of depositional features linked to the up to 150 m thick sedimentary record of the glacial cycles. Whereas the eastern segment (outer foreland province) is devoid of significant glacial-related deposits, the central segment (inner foreland and fold-and thrust belt provinces) shows evidence of repeated advances and retreats of the Magellan glacier. An important moraine ridge complex, probably corresponding to the glacial advance “D”of Clapperton et al., has been seismically imaged in the central segment, as well as an older, large bank of ice distal sediments that have been interpreted as proglacial lake deposits, which show evident signs of repeated glacial erosions. Ice-contact features in the form of frontal moraine complexes made up of dipping foreset strata are present in the fjord-like, western segment of the Strait (Cordillera province), along with their related ice-proximal and ice-distal facies. Eventually, the occurrence of preglacial sediments tectonized by the Magallanes-Fagnano transform fault has been reported in the same segment. This fact, which is supported by small outcrops reported in the updated geologic map, if substantiated by further investigations (i.e. advanced seismic reprocessing, sea bottom samplings), would prove the relatively young age (Late Miocene?) of the Magallanes-Fagnano transform fault.https://revistes.ub.edu/index.php/GEOACTA/article/view/1922SeismostratigraphyGlacigenic featuresMagallanes-Faganano transform fault. |
| spellingShingle | R. BARTOLE S. DE MURO D. MORELLI F. TOSORATTI Glacigenic features and Tertiary stratigraphy of the Magellan Strait (Southern Chile) Geologica Acta Seismostratigraphy Glacigenic features Magallanes-Faganano transform fault. |
| title | Glacigenic features and Tertiary stratigraphy of the Magellan Strait (Southern Chile) |
| title_full | Glacigenic features and Tertiary stratigraphy of the Magellan Strait (Southern Chile) |
| title_fullStr | Glacigenic features and Tertiary stratigraphy of the Magellan Strait (Southern Chile) |
| title_full_unstemmed | Glacigenic features and Tertiary stratigraphy of the Magellan Strait (Southern Chile) |
| title_short | Glacigenic features and Tertiary stratigraphy of the Magellan Strait (Southern Chile) |
| title_sort | glacigenic features and tertiary stratigraphy of the magellan strait southern chile |
| topic | Seismostratigraphy Glacigenic features Magallanes-Faganano transform fault. |
| url | https://revistes.ub.edu/index.php/GEOACTA/article/view/1922 |
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