Late Cenozoic Stratigraphy of the Southern Terror Rift, Antactica: Implications for Tectonic and Climatic Evolution
This thesis presents an integrated analysis of late Cenozoic (last 14 Ma) glacimarine stratigraphy within the Terror Rift in southern McMurdo Sound, Antarctica. The study area is located in the Windless Bight region of the McMurdo Ice Shelf (NW corner of the Ross Ice Shelf), which overlies a 600 to...
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| Format: | Thesis |
| Language: | unknown |
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2008
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| Online Access: | https://doi.org/10.26686/wgtn.16967290.v1 https://figshare.com/articles/thesis/Late_Cenozoic_Stratigraphy_of_the_Southern_Terror_Rift_Antactica_Implications_for_Tectonic_and_Climatic_Evolution/16967290 |
| Summary: | This thesis presents an integrated analysis of late Cenozoic (last 14 Ma) glacimarine stratigraphy within the Terror Rift in southern McMurdo Sound, Antarctica. The study area is located in the Windless Bight region of the McMurdo Ice Shelf (NW corner of the Ross Ice Shelf), which overlies a 600 to 1000 m-deep bathymetric moat surrounding Ross Island in the depocentral axis of the Victoria Land Basin (VLB). The VLB, one of a number of extensional sedimentary basins within the West Antarctic Rift System, comprises a 7-km-thick succession of syn- and post-rift glacimarine sediments that accumulated during the Oligocene and Miocene periods, respectively. Renewed rifting, known as the Terror Rift, in the centre of the VLB began between 17 to 14 Ma and has accommodated as much as one third of the entire Cenozoic basin-fill. The development of rift-related alkalic volcanoes associated with the Erebus Volcanic Province from c. 5 Ma has produced localised flexural basins/moats around Ross Island that have preserved a thick Pliocene-Pleistocene stratigraphic record. A new stratigraphic architecture is presented for southern Terror Rift based on: (1) the acquisition, processing and interpretation of 73 kilometres of over-ice shelf multi-channel seismic reflection data; (2) correlation of seismic stratigraphy with the integrated chrono-, litho- and cyclostratigraphy of the 1285 m-deep ANDRILL McMurdo Ice Shelf (MIS) Project drill core (AND-1B) using a synthetic seismic-well tie, and time-depth data from a vertical seismic profile (VSP). Five seismic units bounded by regionally-mappable unconformities, which thicken into the centre of the basin, are identified and their relationship to the existing seismic stratigraphy of western VLB (Fielding et al. 2007) is established. In addition, a further 17 mappable seismic surfaces bounding higher-frequency depositional units are identified. The seismic units are interpreted on the basis of characteristic features, seismic facies, and correlations with the lithostratigraphy of the ... |
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