The geological and tectonic evolution of the Transantarctic Mountains: a review

Abstract

The development of the Transantarctic Mountains was initiated with the rifting of Rodinia and the formation of a late Neoproterozoic passive continental margin. In Cambrian time this rift setting evolved into an active margin with batholith emplacement into deformed and lightly metamorphosed upper Neoproterozoic-Cambrian strata, creating the Ross Orogen. Denudation and erosion of the Ross Orogen led to the formation of the pre-Devonian Kukri Erosion Surface on which Devonian quartzose sandstones accumulated in a continental setting. Palaeozoic magmatic arcs were intermittently active along the distal Panthalassan margin. Intracratonic basins developed in Permian time, one of which evolved into a foreland basin clearly related to a Permo-Triassic magmatic arc. The Palaeozoic -early Mesozoic arcs can be traced into both Australasia and South America. In Early Jurassic time the margin migrated outboard simultaneously with the advent of proximal silicic volcanism, emplacement of the Ferrar Large Igneous Province and Gondwana break-up. These events marked the onset of plate margin reorganization, and with it the early uplift of the Transantarctic Mountains. During Cretaceous and later time episodic uplift of the Transantarctic Mountains was accompanied by formation of a major crustal and lithospheric boundary marking the edge of the East Antarctic craton and the regions of crustal attenuation in the Ross (West Antarctic Rift System) and Weddell embayments.

High-precision geochronology links the Ferrar large igneous province with early-Jurassic ocean anoxia and biotic crisis

“…Ferrar dolerite sills, mainly of basaltic-andesite composition, combined with the Dufek layered mafic intrusion, comprise more than 90% of the Ferrar LIP (Ford, 1976;Fleming et al, 1997;Elliot andFleming, 2004, 2008). Together with lesser amounts of mafic pyroclastic rocks and lavas, they form a 3500 km long linear belt along the Transantarctic Mountains (TAM).…”

“…Together with lesser amounts of mafic pyroclastic rocks and lavas, they form a 3500 km long linear belt along the Transantarctic Mountains (TAM). Rocks of similar chemical composition and age can be found in southeast Australia, Tasmania, and New Zealand (summarized in Elliot and Fleming, 2004), and South Africa [Riley, 2005 and references therein]. Cumulative volume of currently exposed Ferrar rocks is estimated at 3.7-5.7 × 10 5 km 3 (Fleming et al, 1997).…”

“…Sills of the Ferrar LIP and the Dufek layered mafic intrusion were emplaced predominately into the Devonian-Triassic sedimentary rock sequences of the Beacon Supegroup (Barrett, 1991;Collinson et al, 1994;Elliot and Fleming, 2004). Sills are commonly 100-200 m thick, rarely in excess of 350 m but up to 700 m thick (Elliot and Fleming, 2004).…”

“…Sills are commonly 100-200 m thick, rarely in excess of 350 m but up to 700 m thick (Elliot and Fleming, 2004). Individual sills can be traced continuously in outcrop for 10s of km and may be correlated for 100s of km (Marsh, 2004).…”

“…Individual sills can be traced continuously in outcrop for 10s of km and may be correlated for 100s of km (Marsh, 2004). Cumulative sill thickness within the Beacon Supergroup may reach 1500 m in some regions (Elliot, 2013). In rare cases Ferrar sills intrude pyroclastic rocks at the base of the lava sequences, but they have not been observed to cut the lavas (Elliot and Fleming, 2008).…”