Arc Boudinage, Basin Inversion and Obduction in an Evolving Subduction System of East Antarctica
The paleo-Pacific margin of Gondwana experienced protracted subduction and accretionary tectonics starting in late Neoproterozic-early Cambrian times. Northern Victoria Land (NVL), in East Antarctica, preserves a cryptic record of these active margin processes. Most models indicate that NVL contains...
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ftunivgenova:oai:iris.unige.it:11567/854299 2024-01-28T10:00:07+01:00 Arc Boudinage, Basin Inversion and Obduction in an Evolving Subduction System of East Antarctica BALBI, PIETRO FERRACCIOLI, FAUSTO ARMADILLO, EGIDIO CRISPINI, LAURA CAPPONI, GIOVANNI Balbi, Pietro Ferraccioli, Fausto Armadillo, Egidio Crispini, Laura Capponi, Giovanni 2014 ELETTRONICO http://hdl.handle.net/11567/854299 eng eng ispartofbook:Abstract AGU Fall Meeting 2014 AGU Fall Meeting 2014 firstpage:1 lastpage:1 numberofpages:1 http://hdl.handle.net/11567/854299 info:eu-repo/semantics/conferenceObject 2014 ftunivgenova 2024-01-03T17:52:00Z The paleo-Pacific margin of Gondwana experienced protracted subduction and accretionary tectonics starting in late Neoproterozic-early Cambrian times. Northern Victoria Land (NVL), in East Antarctica, preserves a cryptic record of these active margin processes. Most models indicate that NVL contains three main terranes, namely the Robertson Bay, Bowers and Wilson terranes. Significant debate centres, however, on whether these are far travelled terranes with respect to the East Antarctic Craton, and on the tectonic and magmatic processes that affected its active margin and were ultimately responsible for the formation of the Ross Orogen. Here we interpret new aeromagnetic, aerogravity and land-gravity compilations that enable us to trace the extent of major subglacial faults in the basement of NVL, examine crustal architecture, and propose a new evolutionary model for the active margin of the craton. Prominent aeromagnetic anomalies at the edge of the Wilkes Subglacial Basin delineate the extent of an early-stage magmatic arc (ca 530 Ma?). This arc may have accreted as an exotic element onto the former Neoproterozoic rifted margin of East Antarctica or (perhaps more likely) developed in situ upon a pre-existing suture. Remnants of magnetic arc basement are also identified ca 150 km further to the east within the Wilson Terrane (WT). We propose that these were originally adjacent arc segments and that transtension triggered significant arc boudinage separating these segments. Transtension may have created accommodation space for the development of thick Cambrian sedimentary basins, which are marked by regional magnetic lows with an en-echelon geometry. Basin inversion likely occurred in a later traspressional stage of the Ross-Delamerian Orogen (ca. 490-460 Ma) that triggered the development of a major pop-up structure within the WT. Several buried thrusts of the pop-up can be traced in the aeromagnetic images and a prominent residual gravity high delineates its high-grade metamorphic core. High amplitude magnetic ... Conference Object Antarc* Antarctic Antarctica East Antarctica Victoria Land Università degli Studi di Genova: CINECA IRIS Antarctic East Antarctica Victoria Land Pacific Bowers ENVELOPE(164.083,164.083,-85.000,-85.000) Wilkes Subglacial Basin ENVELOPE(145.000,145.000,-75.000,-75.000) Robertson Bay ENVELOPE(170.000,170.000,-71.417,-71.417) |
institution |
Open Polar |
collection |
Università degli Studi di Genova: CINECA IRIS |
op_collection_id |
ftunivgenova |
language |
English |
description |
The paleo-Pacific margin of Gondwana experienced protracted subduction and accretionary tectonics starting in late Neoproterozic-early Cambrian times. Northern Victoria Land (NVL), in East Antarctica, preserves a cryptic record of these active margin processes. Most models indicate that NVL contains three main terranes, namely the Robertson Bay, Bowers and Wilson terranes. Significant debate centres, however, on whether these are far travelled terranes with respect to the East Antarctic Craton, and on the tectonic and magmatic processes that affected its active margin and were ultimately responsible for the formation of the Ross Orogen. Here we interpret new aeromagnetic, aerogravity and land-gravity compilations that enable us to trace the extent of major subglacial faults in the basement of NVL, examine crustal architecture, and propose a new evolutionary model for the active margin of the craton. Prominent aeromagnetic anomalies at the edge of the Wilkes Subglacial Basin delineate the extent of an early-stage magmatic arc (ca 530 Ma?). This arc may have accreted as an exotic element onto the former Neoproterozoic rifted margin of East Antarctica or (perhaps more likely) developed in situ upon a pre-existing suture. Remnants of magnetic arc basement are also identified ca 150 km further to the east within the Wilson Terrane (WT). We propose that these were originally adjacent arc segments and that transtension triggered significant arc boudinage separating these segments. Transtension may have created accommodation space for the development of thick Cambrian sedimentary basins, which are marked by regional magnetic lows with an en-echelon geometry. Basin inversion likely occurred in a later traspressional stage of the Ross-Delamerian Orogen (ca. 490-460 Ma) that triggered the development of a major pop-up structure within the WT. Several buried thrusts of the pop-up can be traced in the aeromagnetic images and a prominent residual gravity high delineates its high-grade metamorphic core. High amplitude magnetic ... |
author2 |
Balbi, Pietro Ferraccioli, Fausto Armadillo, Egidio Crispini, Laura Capponi, Giovanni |
format |
Conference Object |
author |
BALBI, PIETRO FERRACCIOLI, FAUSTO ARMADILLO, EGIDIO CRISPINI, LAURA CAPPONI, GIOVANNI |
spellingShingle |
BALBI, PIETRO FERRACCIOLI, FAUSTO ARMADILLO, EGIDIO CRISPINI, LAURA CAPPONI, GIOVANNI Arc Boudinage, Basin Inversion and Obduction in an Evolving Subduction System of East Antarctica |
author_facet |
BALBI, PIETRO FERRACCIOLI, FAUSTO ARMADILLO, EGIDIO CRISPINI, LAURA CAPPONI, GIOVANNI |
author_sort |
BALBI, PIETRO |
title |
Arc Boudinage, Basin Inversion and Obduction in an Evolving Subduction System of East Antarctica |
title_short |
Arc Boudinage, Basin Inversion and Obduction in an Evolving Subduction System of East Antarctica |
title_full |
Arc Boudinage, Basin Inversion and Obduction in an Evolving Subduction System of East Antarctica |
title_fullStr |
Arc Boudinage, Basin Inversion and Obduction in an Evolving Subduction System of East Antarctica |
title_full_unstemmed |
Arc Boudinage, Basin Inversion and Obduction in an Evolving Subduction System of East Antarctica |
title_sort |
arc boudinage, basin inversion and obduction in an evolving subduction system of east antarctica |
publishDate |
2014 |
url |
http://hdl.handle.net/11567/854299 |
long_lat |
ENVELOPE(164.083,164.083,-85.000,-85.000) ENVELOPE(145.000,145.000,-75.000,-75.000) ENVELOPE(170.000,170.000,-71.417,-71.417) |
geographic |
Antarctic East Antarctica Victoria Land Pacific Bowers Wilkes Subglacial Basin Robertson Bay |
geographic_facet |
Antarctic East Antarctica Victoria Land Pacific Bowers Wilkes Subglacial Basin Robertson Bay |
genre |
Antarc* Antarctic Antarctica East Antarctica Victoria Land |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Victoria Land |
op_relation |
ispartofbook:Abstract AGU Fall Meeting 2014 AGU Fall Meeting 2014 firstpage:1 lastpage:1 numberofpages:1 http://hdl.handle.net/11567/854299 |
_version_ |
1789340350988419072 |