Trace of the Kerguelen mantle plume: Evidence from seamounts between the Kerguelen Archipelago and Heard Island, Indian Ocean. ...
The gravity and bathymetric highs on the Kerguelen Plateau in the southern Indian Ocean between the Kerguelen Archipelago and Heard Island are seamounts formed of Miocene alkalic basalts similar to those found on the islands. Dredging during the Kerimis survey cruise recovered >1 ton of mostly ba...
| Main Authors: | , |
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| Format: | Text |
| Language: | English |
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American Geophysical Union
2016
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| Online Access: | https://dx.doi.org/10.14288/1.0075978 https://doi.library.ubc.ca/10.14288/1.0075978 |
| Summary: | The gravity and bathymetric highs on the Kerguelen Plateau in the southern Indian Ocean between the Kerguelen Archipelago and Heard Island are seamounts formed of Miocene alkalic basalts similar to those found on the islands. Dredging during the Kerimis survey cruise recovered >1 ton of mostly basaltic rocks. One of the dredges (D6) yielded a large volume of in situ alkalic picritic pillow basalts, the first picritic lavas recovered that are related to the Kerguelen plume. K-Ar and 40Ar-39Ar ages are between 18 and 21 Ma for all but one sample, and these ages are only slightly younger than the main phase of volcanism on the archipelago. The dredged lavas form three distinct groups based on chemical and isotopic compositions. Incompatible element abundance ratios overlap with compositional groups defined by lavas from both the Kerguelen Archipelago and Heard Island indicating that alkalic volcanism in this region of the Kerguelen Plateau has been spatially diverse. Olivine and picritic basalts have Sr and ... |
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