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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Main Authors: BALBI, PIETRO, FERRACCIOLI, FAUSTO, ARMADILLO, EGIDIO, CRISPINI, LAURA, CAPPONI, GIOVANNI
Other Authors: Balbi, Pietro, Ferraccioli, Fausto, Armadillo, Egidio, Crispini, Laura, Capponi, Giovanni
Format: Conference Object
Language:English
Published: 2014
Subjects:
Online Access:http://hdl.handle.net/11567/854299
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spelling 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
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