Prince Edward Fracture Zone
The Prince Edward Fracture Zone (PEFZ) is one of the fracture zones located on the Southwest Indian Ridge in the Indian Ocean between Africa and Antarctica. The PEFZ is located west of Prince Edward Islands.
The history of seafloor spreading between Africa and Antarctica since the breakup of Gondwana can be traced using magnetic anomaly lineations between the Mozambique Channel and the seafloor of Dronning Maud Land. Before the 1980s it was assumed that this spreading occurred continuously for 80 million years, from the Cretaceous to present, along the fracture zones flanking the mid-ocean ridge. In the mid-80s new magnetic lineations discovered near the PEFZ made it clear that a change in the spreading direction occurred 74–56 Ma.[1] As the direction of spreading changed so did the phase.[2]
The largest offset along the Southwest Indian Ridge (800 km (500 mi)) is located west of the PEFZ and east of the Du Toit Fracture Zone (45°S, 35°E; 53°S, 27°E). During the Late Cretaceous this offset was smaller than 250 km (160 mi).[3]
Antarctic Bottom Water flows north through the PEFZ.[4]
References
Notes
- Royer et al. 1988, Introduction, pp. 235–237
- Royer et al. 1988, Figg 7. a-j
- Royer et al. 1988, p. 241
- Rogers 2012, The Southern Indian Ocean and its Seamounts, pp. 5–6
Sources
- Rogers, A. (2012). Volume 1: Overview of seamount ecosystems and biodiversity (PDF). An ecosystem approach to management of seamounts in the Southern Indian Ocean. IUCN. Retrieved 11 May 2019.
- Royer, J. Y.; Patriat, P.; Bergh, H. W.; Scotese, C. R. (1988). "Evolution of the Southwest Indian Ridge from the Late Cretaceous (anomaly 34) to the Middle Eocene (anomaly 20)". Tectonophysics. 155 (1–4): 235–260. Bibcode:1988Tectp.155..235R. doi:10.1016/0040-1951(88)90268-5. Retrieved 31 July 2016.