Gondwana Breakup: The South American, African and Indian plate movements and remaining problems.
Geological mapping and geophysical data indicate that the geological history of the EastAntarctic between Berkner Island in the west and Enderby Land in the east faced severalgeological events, which are not fully understood. The main information on the sub-icegeology is provided by aerogeophysical...
| Main Authors: | , |
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| Format: | Conference Object |
| Language: | unknown |
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2007
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| Online Access: | https://epic.awi.de/id/eprint/16887/ https://epic.awi.de/id/eprint/16887/1/Jok2007e.pdf https://hdl.handle.net/10013/epic.26726 https://hdl.handle.net/10013/epic.26726.d001 |
| Summary: | Geological mapping and geophysical data indicate that the geological history of the EastAntarctic between Berkner Island in the west and Enderby Land in the east faced severalgeological events, which are not fully understood. The main information on the sub-icegeology is provided by aerogeophysical investigations. However, these surveys are somehowlogistically limited to a region, which is parallel to the coast line. Thus, large parts of the innerAntarctic continent are only sparsely surveyed due to the lack of long-range aircrafts, whichcan operate also in these remote areas. As a consequence geological units, which areidentified in the coastal or near coastal mountain ranges, cannot be followed into the interior.Thus, most of the models, which predict the continuation of the geological features from thesurrounding continents into the Antarctic craton are still highly speculative. Thus, weconcentrate in this contribution on the aero/marine magnetic investigations, which aim tofurther constrain the plate movements since 160 Myr, and thus provide a good fit. This mightfacilitate at a later stage the correlation of geological units across the continents, if there is anycontinuation. The areas and remaining problems from our perspective are described(Abbreviations: SAM-South America, ANT-Antarctica, FRS-Filchner-Ronne Shelf, EANTEastAntarctica, WANT-West Antarctica, AFR-Africa, IND-India):South America-AntarcticaAccording to the latest models SAM was situated deep in the southern Weddell Sea. Thebreak-up with the formation of oceanic crust started some 148 Ma (König and Jokat, 2006)with spreading rates around 1-2 cm/yr. Slow to ultra-slow spreading rates dominated thedocumented drift history of ANT and SAM. The magnetic anomalies in the southwesternWeddell Sea are for unknown reasons- not well developed. A short high resolution magneticsurvey along the Larsen rifted margin did not show any continuous magnetic anomalies,which would allow to better describe the evolution of this area. It is questionable, if a ... |
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