Tectonic development of the Bransfield Basin and its prolongation to the South Scotia Ridge, northern Antarctic Peninsula

Galindo-Zaldı́var, Jesús; Gambôa, Luiz Antônio Pierantoni; Maldonado, Andrés; Nakao, Shigeru; Bochu, Yao

doi:10.1016/j.margeo.2004.02.007

Cited by 60 publications

(52 citation statements)

References 34 publications

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“…Trench-rollback style subduction in the SST proposed by many scientists (Barker, 1982;Larter and Barker, 1991;Maldonado et al, 1994;Galindo-Zaldívar et al, 2004) may offer an alternative scenario. In case of combining the tectonic model of Galindo-Zaldívar et al (2004) and current short width of normal fault zone in the SST, another possible scenario is that (1) subduction with normal faulting had continued up to 3.3 Ma or before (top, Fig.…”

Section: Scenarios For Subduction History In the South Shetland Trenchmentioning

confidence: 99%

“…In case of combining the tectonic model of Galindo-Zaldívar et al (2004) and current short width of normal fault zone in the SST, another possible scenario is that (1) subduction with normal faulting had continued up to 3.3 Ma or before (top, Fig. 5b); (2) trench roll-back without normal faulting began at 3.3 Ma (middle, Fig.…”

Section: Scenarios For Subduction History In the South Shetland Trenchmentioning

confidence: 99%

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Is subduction ongoing in the South Shetland Trench, Antarctic Peninsula?: new constraints from crustal structures of outer trench wall

et al. 2009

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The South Shetland Trench (SST) northwest of the South Shetland Islands is the only trench along the Pacific margin of the Antarctic Peninsula. Multichannel seismic reflection profile shows very narrow normal faulting zone (about 20 km) on the outer wall of the SST and thick trench-fill sediments (up to 1000 m) on two distinct crustal horst and graben structures in the trench. These structures are rare in the active subduction trenches. On the basis of the implications from these seismic structures and known tectonic history, the following scenarios of subduction activities of the former Phoenix plate are proposed: (1) normal faulting has not occurred since subduction rate in the SST sharply decreased after cessation of seafloor spreading at the West Scotia Ridge at about 6 Ma; and (2) subduction almost stopped after the cessation of spreading in Drake Passage at about 3.3 Ma. Recent contractional structures around the SST are indicative of current crustal shortening (not subduction) accommodating trenchward movement of South Shetland Islands caused by the ongoing extension of Bransfield Basin behind the South Shetland Islands.

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Section: Scenarios For Subduction History In the South Shetland Trenchmentioning

confidence: 99%

Section: Scenarios For Subduction History In the South Shetland Trenchmentioning

confidence: 99%

Is subduction ongoing in the South Shetland Trench, Antarctic Peninsula?: new constraints from crustal structures of outer trench wall

et al. 2009

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“…Se trata de un archipiélago formado por una decena de islas distribuidas a lo largo de 120 km en disposición SSW-NNE. Este archipiélago está emplazado en una zona tectónicamente muy activa y su evolución geológica está aún en discusión (Galindo-Zaldívar et al, 2004;Alfaro et al, 2010;Catalán et al, 2013;Galé et al, 2014).…”

Section: áRea De Estudiounclassified

La deglaciación de las áreas libres de hielo de las islas Shetland del Sur (Antártida). Ejemplos de Byers (Livingston) y Barton (King George)

Oliva

Antoniades

Giralt³

et al. 2016

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The process of deglaciation of the present-day ice-free environments in the Maritime Antarctica has profound geomorphological and ecological implications. However, the timing of glacier retreat is still poorly understood. This is the case of the deglaciated areas existing in Byers (Livingston Island) and Barton (King George Island) peninsulas. The dating of the basal sediments collected from different lakes in these two peninsulas allowed inferences of the ages of formation of each lake. The integration of these ages enables the reconstruction ofthe spatial and temporal pattern of deglaciation of these areas. The chronological framework has been establishedusing two complementary techniques: radiocarbon and thermoluminescence dating. In both peninsulas the deglaciation started during the Early Holocene, around 8 ka cal BP. The areas located far away from the current ice domes and the highest peaks in the two peninsulas (nunataks) were the first areas to become ice -free. During the mid-Holocene (5-6 ka cal BP) the central part of these peninsulas was progressively deglaciated. Finally, during the Late Holocene glacier fronts remained confined to the current position defined by the present frontal moraines, with minor advances and retreats.

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“…Following cessation of spreading, rollback of the subducting slab beneath the present‐day South Shetland margin led to the opening and development of the Bransfield Basin, an elongated Late‐Pliocene‐to‐recent back‐arc basin [e.g., Gambôa and Maldonado , 1990; Gracia et al , 1996a, 1996b; Barker and Austin , 1998]. Some authors have proposed that the rift extends and merges eastward into an active fault zone within the South Scotia Ridge and accommodates the left‐lateral transcurrent deformation acting along this continental segment [ González‐Casado et al , 2000; Galindo‐Zaldívar et al , 2004]. …”

Section: Western Scotia Sea Tectonic Evolutionmentioning

confidence: 99%

Western Scotia Sea margins: Improved constraints on the opening of the Drake Passage

2006

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[ 1 ] We present arevised tectonic interpretation (from $ 28 Ma to 3.2 Ma) of the western sector of the Scotia Sea, incorporating new multichannel seismic reflection profiles and magnetic anomaly identifications for the continental margin offt he Tierra del Fuego Island, and available complementary data for the conjugate margin of the northwestern flank of the South Scotia Ridge. Seismic profiles show ar emarkable diversity of the pair of conjugate passive margins of the western Scotia Sea in both their morphology and structural framework. The Tierra del Fuego continental margin can be related to ac lassic rifted passive margin, while the southwestern margin of the Scotia Sea is characterized by steep slopes mostly generated by subvertical faults that abruptly separate the continental crust of the South Scotia Ridge from the oceanic crust of the western Scotia Sea. This structural difference was caused by intense strike-slip tectonism, mostly concentrated along the modern South Scotia Ridge since the early development of the western Scotia Sea. We find evidence for ap reviously unrecognized magnetic anomaly 10 ( $ 28 Ma) at the foot of the Tierra del Fuego continental margin; the same anomaly is present at the conjugate northern flank of the South Scotia Ridge. The timing of events leading to the earliest development of the western Scotia Sea, which determined the opening of the Drake Passage is important because this gateway opening had aprofound effect on global circulation and climate. The thickness and the distribution of the sedimentary cover overall in the abyssal plain offt he two western Scotia Sea margins is different. This is due to the different regimes of the bottom-current flows which affected the western Scotia Sea, both in the past and in the present time.

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Tectonic development of the Bransfield Basin and its prolongation to the South Scotia Ridge, northern Antarctic Peninsula

Cited by 60 publications

References 34 publications

Is subduction ongoing in the South Shetland Trench, Antarctic Peninsula?: new constraints from crustal structures of outer trench wall

Is subduction ongoing in the South Shetland Trench, Antarctic Peninsula?: new constraints from crustal structures of outer trench wall

La deglaciación de las áreas libres de hielo de las islas Shetland del Sur (Antártida). Ejemplos de Byers (Livingston) y Barton (King George)

Western Scotia Sea margins: Improved constraints on the opening of the Drake Passage

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