Post 3.9 Ma fault activity within the West Antarctic rift system: onshore evidence from Gandalf Ridge, Mount Morning eruptive centre, southern Victoria Land, Antarctica
2010; Cambridge University Press; Volume: 22; Issue: 5 Linguagem: Inglês
10.1017/s095410201000026x
ISSN1365-2079
AutoresAdam P. Martin, Alan F. Cooper,
Tópico(s)Geological formations and processes
ResumoAbstract A hawaiite dyke dated at 3.88 ± 0.05 Ma from the Mount Morning eruptive centre intrudes a diamictite deposit at Gandalf Ridge in the southern Ross Sea. The dyke has been dextrally offset up to 6 m horizontally by faults interpreted as the onshore continuation of the West Antarctic rift system (WARS) fault array. Felsic dykes emplaced during the Miocene are also present at Gandalf Ridge. The offset of the Miocene dykes is equivalent to the offset on the hawaiite dyke, suggesting that at this locality movement on faults within WARS has been restricted to a period more recent than c . 3.88 Ma. Over this period the minimum average rate of movement on these faults within WARS is 0.0015 mm yr -1 .
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