Geodynamic evolution of the Antarctic Peninsula during Mesozoic times and its bearing on Weddell Sea history

New geophysical compilations link crustal block motion to Jurassic extension and strike-slip faulting in the Weddell Sea Rift System of West Antarctica

“…The WSRS is shown in our new magnetic compilation to include two distinct sub-provinces ( anomalies of these different provinces have been recognised and discussed previously (Ferris et al, 2000;Golynsky and Aleshkova, 1997b), and a broad extended continental Filchner Block has been proposed for the entire WSRS region (Dalziel and Lawver, 2001;Jokat et al, 1997;Storey et al, 1996b;Studinger and Miller, 1999). The two provinces we define within the previously identified Weddell Sea Magnetic Zone/Filchner Block are identified primarily based on the internal consistency of trends (Fig 4) within the different regions.…”

“…Alternative tectonic models for Jurassic rotation and translation of a broader HEW and a pre-existing continental Filchner block (Storey et al, 1996b) do not have clear kinematic markers within the WSRS either. Additionally, some plate tectonic models have been used to propose that substantial independent movement of the HEW microplate is not required as part of Gondwana breakup (Eagles and Vaughan, 2009).…”

Crustal structure of the Filchner‐Ronne Shelf and Coats Land, Antarctica, from gravity and magnetic data: Implications for the breakup of Gondwana

“…(Figure 3b). A possible explanation for the rotation and translation of the EWM block could be the doming of the lithosphere in the vicinity of the Karoo plume [Storey et al, 1996]. However, they find no adequate mechanism to explain the rotation and translation of the EWM crustal block.…”

“…Storey et al [ 1996] pointed out that west-directed subduction of relatively young proto-Weddell Sea oceanic crust on the east side of the Antarctic Peninsula, combined with ongoing eastward Pacific subduction, is unlikely. The subduction of proto-Weddell Sea cannot explain the Palmer Land deformation, and therefore the geological evidence for subduction is inconclusive [Storey et al, 1996] (Figure 3b). This would preclude the need for large proto-Weddell Sea floor [Storey et al, 1996].…”

“…The subduction of proto-Weddell Sea cannot explain the Palmer Land deformation, and therefore the geological evidence for subduction is inconclusive [Storey et al, 1996] (Figure 3b). This would preclude the need for large proto-Weddell Sea floor [Storey et al, 1996]. The goal of the present study is to contribute geophysical constraints that may provide new insights on the late Mesozoic movement of the EWM crustal block.…”