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Widespread Neogene volcanism on Central Kerguelen Plateau, Southern Indian Ocean

Citation

Duncan, RA and Falloon, TJ and Quilty, PG and Coffin, MF, Widespread Neogene volcanism on Central Kerguelen Plateau, Southern Indian Ocean, Australian Journal of Earth Sciences, 63, (4) pp. 379-392. ISSN 0812-0099 (2016) [Refereed Article]

Copyright Statement

Copyright 2016 Geological Society of Australia

DOI: doi:10.1080/08120099.2016.1221857

Abstract

We report new age determinations and compositions for rocks from 18 dredge hauls collected from eight submarine areas across Central Kerguelen Plateau (CKP). Sea knolls and volcanic fields with multiple small cones were targeted over a ∼125 000 km2 region that includes Heard and McDonald Islands. Large early Miocene (22–16 Ma) sea knolls rise from the western margin of the CKP and are part of a NNW–SSE line of volcanic centres that lie between Îles Kerguelen and Heard and McDonald Islands. These are probably related to hotspot activity now underlying the Heard Island area. We see evidence of much younger activity (5 Ma to present) in volcanic fields to the north of, and up to 300 km NE of, Heard Island. Compositions include basanite, basalt and trachybasalt, which are broadly similar to plateau lava flows from nearby Ocean Drilling Program Site 1138, lower Miocene lavas at Îles Kerguelen, dredged rocks from the early Miocene sea knolls, and Big Ben lavas from Heard Island. Geochemical data indicate decreasing fractions of mantle source melting with time. We propose that a broad region of the CKP became volcanically active in Neogene time owing to incubation of plume material at the base of the relatively stationary overlying plateau. The presence of pre-existing crustal faults gave access for melts from the Heard mantle plume to rise to the surface.

Item Details

Item Type:Refereed Article
Keywords:age determinations, basalt compositions, ocean plateau, submarine volcanism, hotspot, plume incubation
Research Division:Earth Sciences
Research Group:Geology
Research Field:Volcanology
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Earth Sciences
Author:Falloon, TJ (Dr Trevor Falloon)
Author:Quilty, PG (Dr Pat Quilty)
Author:Coffin, MF (Professor Mike Coffin)
ID Code:111145
Year Published:2016
Deposited By:Centre for Oceans and Cryosphere
Deposited On:2016-08-31
Last Modified:2017-11-17
Downloads:0

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