Structural controls on sulphide deposition at the dyke-lava boundary, slow-spreading ocean crust, Macquarie Island
Ocean Drilling Program hole 504B revealed an ocean crust hydrothermal sulphur anomaly on the dyke-lava transition, with implications for global sulphur sinks. Here we confirm the presence of the anomaly sporadically along 7.5 km of dyke-basalt contact on the Macquarie Ridge at Macquarie Island, a 39...
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ftunivtasmania:oai:eprints.utas.edu.au:715 2023-05-15T17:09:55+02:00 Structural controls on sulphide deposition at the dyke-lava boundary, slow-spreading ocean crust, Macquarie Island Davidson, GJ Varne, R Brown, AV Connell, R 2004-02 application/pdf https://eprints.utas.edu.au/715/ https://eprints.utas.edu.au/715/1/Garry_TerraNovaFinal.pdf https://doi.org/10.1046/j.1365-3121.2003.00518.x en eng https://eprints.utas.edu.au/715/1/Garry_TerraNovaFinal.pdf Davidson, GJ, Varne, R, Brown, AV and Connell, R 2004 , 'Structural controls on sulphide deposition at the dyke-lava boundary, slow-spreading ocean crust, Macquarie Island' , Terra Nova, vol. 16, no. 1 , pp. 9-15 , doi:10.1046/j.1365-3121.2003.00518.x <http://dx.doi.org/10.1046/j.1365-3121.2003.00518.x>. cc_utas 260100 Geology Article PeerReviewed 2004 ftunivtasmania https://doi.org/10.1046/j.1365-3121.2003.00518.x 2020-05-30T07:14:26Z Ocean Drilling Program hole 504B revealed an ocean crust hydrothermal sulphur anomaly on the dyke-lava transition, with implications for global sulphur sinks. Here we confirm the presence of the anomaly sporadically along 7.5 km of dyke-basalt contact on the Macquarie Ridge at Macquarie Island, a 39-9.7 Ma slow-spreading setting. Background contact-zone pyrite S contents average 1845 p.p.m. across ~50 m. However, zones of small-scale brittle faulting that commonly occur on and above the dyke-basalt contact average between 5000 and 11 000 p.p.m. S (20-30 m widths). These consist of steep ridgeparallel faults and fault splays on the contact, overlain by up to 50 m of linked pyritic fault trellis. The contact zone faults are haloed by disseminated pyrite-chlorite, cross-cut by quartz-chlorite-sphalerite and epidote-cemented breccias, containing evidence of turbulent flow. The structural control on sulphur deposition is attributed to the active extensional slow spreading setting. With increasing extension, diffuse mixing across the contact was replaced by channellized flow and dynamic mixing in fault arrays. The magnitude of the dyke-lava transition sulphur sink must be reassessed to take account of this heterogeneity. Article in Journal/Newspaper Macquarie Island University of Tasmania: UTas ePrints Terra Nova 16 1 9 15 |
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Open Polar |
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University of Tasmania: UTas ePrints |
op_collection_id |
ftunivtasmania |
language |
English |
topic |
260100 Geology |
spellingShingle |
260100 Geology Davidson, GJ Varne, R Brown, AV Connell, R Structural controls on sulphide deposition at the dyke-lava boundary, slow-spreading ocean crust, Macquarie Island |
topic_facet |
260100 Geology |
description |
Ocean Drilling Program hole 504B revealed an ocean crust hydrothermal sulphur anomaly on the dyke-lava transition, with implications for global sulphur sinks. Here we confirm the presence of the anomaly sporadically along 7.5 km of dyke-basalt contact on the Macquarie Ridge at Macquarie Island, a 39-9.7 Ma slow-spreading setting. Background contact-zone pyrite S contents average 1845 p.p.m. across ~50 m. However, zones of small-scale brittle faulting that commonly occur on and above the dyke-basalt contact average between 5000 and 11 000 p.p.m. S (20-30 m widths). These consist of steep ridgeparallel faults and fault splays on the contact, overlain by up to 50 m of linked pyritic fault trellis. The contact zone faults are haloed by disseminated pyrite-chlorite, cross-cut by quartz-chlorite-sphalerite and epidote-cemented breccias, containing evidence of turbulent flow. The structural control on sulphur deposition is attributed to the active extensional slow spreading setting. With increasing extension, diffuse mixing across the contact was replaced by channellized flow and dynamic mixing in fault arrays. The magnitude of the dyke-lava transition sulphur sink must be reassessed to take account of this heterogeneity. |
format |
Article in Journal/Newspaper |
author |
Davidson, GJ Varne, R Brown, AV Connell, R |
author_facet |
Davidson, GJ Varne, R Brown, AV Connell, R |
author_sort |
Davidson, GJ |
title |
Structural controls on sulphide deposition at the dyke-lava boundary, slow-spreading ocean crust, Macquarie Island |
title_short |
Structural controls on sulphide deposition at the dyke-lava boundary, slow-spreading ocean crust, Macquarie Island |
title_full |
Structural controls on sulphide deposition at the dyke-lava boundary, slow-spreading ocean crust, Macquarie Island |
title_fullStr |
Structural controls on sulphide deposition at the dyke-lava boundary, slow-spreading ocean crust, Macquarie Island |
title_full_unstemmed |
Structural controls on sulphide deposition at the dyke-lava boundary, slow-spreading ocean crust, Macquarie Island |
title_sort |
structural controls on sulphide deposition at the dyke-lava boundary, slow-spreading ocean crust, macquarie island |
publishDate |
2004 |
url |
https://eprints.utas.edu.au/715/ https://eprints.utas.edu.au/715/1/Garry_TerraNovaFinal.pdf https://doi.org/10.1046/j.1365-3121.2003.00518.x |
genre |
Macquarie Island |
genre_facet |
Macquarie Island |
op_relation |
https://eprints.utas.edu.au/715/1/Garry_TerraNovaFinal.pdf Davidson, GJ, Varne, R, Brown, AV and Connell, R 2004 , 'Structural controls on sulphide deposition at the dyke-lava boundary, slow-spreading ocean crust, Macquarie Island' , Terra Nova, vol. 16, no. 1 , pp. 9-15 , doi:10.1046/j.1365-3121.2003.00518.x <http://dx.doi.org/10.1046/j.1365-3121.2003.00518.x>. |
op_rights |
cc_utas |
op_doi |
https://doi.org/10.1046/j.1365-3121.2003.00518.x |
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Terra Nova |
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