Middle Jurassic air fall tuff in the sedimentary Latady Formation, eastern Ellsworth Land
Hunter, Morag A.; Riley, Teal R.; Millar, Ian L.. 2004 Middle Jurassic air fall tuff in the sedimentary Latady Formation, eastern Ellsworth Land. Antarctic Science, 16 (2). 185-190. 10.1017/S0954102004001944Full text not available from this repository. (Request a copy)
Rhyolitic volcanism along the proto-Pacific margin of Gondwana occurred at intervals throughout the Jurassic. Silicic melt generation has been interpreted as a result of interaction between mantle plumes and subduction modified lower crust. The rhyolitic Mount Poster Formation of the southern Antarctic Peninsula is c. 184 Ma in age (VI), whereas silicic volcanism of the northern Antarctic Peninsula is c. 168 Ma (V2). A thin, (13.5 cm) reworked air fall tuff, interbedded with sandstone and mudstone of the Latady Formation in the southern Antarctic Peninsula has a REE pattern similar to V2 volcanic material but is isotopically similar to the extracaldera, low-Ti rhyolites of the VI Mount Poster Formation. The tuff is interbedded with lithofacies that have been assigned a Callovian age (164-159 Ma) in the west of the area. Simple mixing between a MASH source and reworked Early Jurassic (184 Ma) V I volcanic material during V2 volcanism in the area explains the apparent discrepancy between the faunal age and the isotopic characteristics of the ash fall. This supports a Middle Jurassic (168 Ma) age that also corresponds to a 167 3 Ma age from Mt Rex on the periphery of the Mount Poster Formation, which was previously thought to be anomalous.
|Programmes:||BAS Programmes > Antarctic Science in the Global Context (2000-2005) > Antarctica in the Dynamic Global Plate System|
|Additional Keywords:||Antarctic Peninsula, Gondwana, mount poster formation, rhyolite, volcanic|
|NORA Subject Terms:||Earth Sciences|
|Date made live:||18 Jan 2012 14:36|
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