Structural controls on sulphide deposition at the dyke–lava boundary, slow‐spreading ocean crust, Macquarie Island
Abstract 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 Isl...
Published in: | Terra Nova |
---|---|
Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Wiley
2004
|
Subjects: | |
Online Access: | http://dx.doi.org/10.1046/j.1365-3121.2003.00518.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-3121.2003.00518.x https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-3121.2003.00518.x |
id |
crwiley:10.1046/j.1365-3121.2003.00518.x |
---|---|
record_format |
openpolar |
spelling |
crwiley:10.1046/j.1365-3121.2003.00518.x 2024-09-09T19:51:44+00:00 Structural controls on sulphide deposition at the dyke–lava boundary, slow‐spreading ocean crust, Macquarie Island Davidson, Garry J. Varne, Rick Brown, Anthony V. Connell, Robert 2004 http://dx.doi.org/10.1046/j.1365-3121.2003.00518.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-3121.2003.00518.x https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-3121.2003.00518.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Terra Nova volume 16, issue 1, page 9-15 ISSN 0954-4879 1365-3121 journal-article 2004 crwiley https://doi.org/10.1046/j.1365-3121.2003.00518.x 2024-06-20T04:26:30Z Abstract 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 ridge‐parallel 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 Wiley Online Library Terra Nova 16 1 9 15 |
institution |
Open Polar |
collection |
Wiley Online Library |
op_collection_id |
crwiley |
language |
English |
description |
Abstract 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 ridge‐parallel 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, Garry J. Varne, Rick Brown, Anthony V. Connell, Robert |
spellingShingle |
Davidson, Garry J. Varne, Rick Brown, Anthony V. Connell, Robert Structural controls on sulphide deposition at the dyke–lava boundary, slow‐spreading ocean crust, Macquarie Island |
author_facet |
Davidson, Garry J. Varne, Rick Brown, Anthony V. Connell, Robert |
author_sort |
Davidson, Garry J. |
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 |
publisher |
Wiley |
publishDate |
2004 |
url |
http://dx.doi.org/10.1046/j.1365-3121.2003.00518.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1046%2Fj.1365-3121.2003.00518.x https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1365-3121.2003.00518.x |
genre |
Macquarie Island |
genre_facet |
Macquarie Island |
op_source |
Terra Nova volume 16, issue 1, page 9-15 ISSN 0954-4879 1365-3121 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1046/j.1365-3121.2003.00518.x |
container_title |
Terra Nova |
container_volume |
16 |
container_issue |
1 |
container_start_page |
9 |
op_container_end_page |
15 |
_version_ |
1809921017042173952 |