| Summary: | Spreading in the Adare Basin off north-western Ross Sea (43–26 Ma) and extension in the Victoria Land Basin (VLB, > 36 Ma) are used to constrain the pole of rotation for the Adare Basin, providing a rifting model for the region for the past 45 Ma. The offset from Northern Basin to VLB at about 74°S coincides with the linear Polar-3 magnetic anomaly, inferred to be caused by a major 48 - 34 Ma igneous intrusion. The style of extension apparently changed at about 34 Ma, with the end of intrusion at the Polar-3 anomaly, a change from highly asymmetric extension in Adare Basin, and the onset of major subsidence on the flanks of VLB. Ductile lower crustal and lithospheric flow is proposed as the cause of the inferred thick crust underlying southern Adare Basin, and a result of the constraining of extension to the adjacent contiguous Northern Basin. © 2006 American Geophysical Union. Manuscript Accepted: 19 Sep 2006. Manuscript Received: 24 Jul 2006. Article first published online: 27 Oct 2006. We greatly appreciated a review of the manuscript by an anonymous reviewer. We acknowledge the support of the Captain and crew of R/V NB Palmer during the acquisition of data over southern Adare Basin. The research was supported by NSF grants OPP-0338346 (S Cande) and OPP-0338317 (J. Stock), by the NZ Foundation for Research, Science and Technology and the NZ GSF (F. Davey). Published - grl22102.pdf
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