Skip Navigation

Journal of Petrology 2004 45(7):1453-1465; doi:10.1093/petrology/egh025
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (1)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by MILLER, S.
Right arrow Articles by MACDONALD, D. I. M.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Journal of Petrology 45(7) © Oxford University Press 2004; all rights reserved

Metamorphic and Thermal History of a Fore-Arc Basin: the Fossil Bluff Group, Alexander Island, Antarctica

S. MILLER1,2,* and D. I. M. MACDONALD1,3

1 BRITISH ANTARCTIC SURVEY, NERC, HIGH CROSS, MADINGLEY ROAD, CAMBRIDGE CB3 0ET, UK
2 PRESENT ADDRESS: NATIONAL MUSEUMS OF SCOTLAND, CHAMBERS STREET, EDINBURGH EH1 1JF, UK
3 PRESENT ADDRESS: DEPARTMENT OF GEOLOGY & PETROLEUM GEOLOGY, UNIVERSITY OF ABERDEEN, MESTON BUILDING, ABERDEEN AB24 3UE, UK

* Corresponding author. Telephone: +44 (0)131 247 4007. Fax: +44 (0)131 220 4819. E-mail: s.miller{at}nms.ac.uk

The Himalia Ridge Formation (Fossil Bluff Group), Alexander Island is a 2·2-km-thick sequence of Upper Jurassic–Lower Cretaceous conglomerates, sandstones and mudstones, derived from an andesitic volcanic arc and deposited in a fore-arc basin. The metamorphic and thermal history of the formation has been determined using authigenic mineral assemblages and vitrinite reflectance measurements. Metamorphic effects include compaction, pore-space reduction, cementation and dissolution and replacement of detrital grains by clay minerals (smectite, illite/smectite, corrensite and kaolinite), calcite, chlorite, laumontite, prehnite, pumpellyite, albite and mica, with less common quartz, haematite, pyrite and epidote. The authigenic mineral assemblages exhibit a depth-dependence, and laumontite and calcite exhibit a strong antipathetic relationship. Detrital organic matter in the argillaceous layers has vitrinite reflectance values (Ro) ranging from 2·3 to 3·7%. This indicates considerable thermal maturation, with a systematic increase in reflectivity with increasing depth. There is good correlation of metamorphic mineral assemblages with chlorite crystallinity and vitrinite reflectance values—all indicating temperatures in the range of 140 ± 20°C at the top of the sequence to 250 ± 10°C at the base of the sequence. The temperatures suggest a geothermal gradient of 36–64°C/km and a most likely gradient of 50°C/km. It is suggested that this higher-than-average gradient for a fore-arc basin resulted either from rifting during basin formation or from a late-stage arc migration event.

KEY WORDS: Antarctica; diagenesis; fore-arc basin; low-temperature metamorphism; vitrinite reflectance


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.