Mount Elkins

Geology & orogeny

Much of the East Antarctic Shield was formed in the Precambrian period by a series of tectonothermal orogenic events. Napier orogeny formed the cratonic nucleus approximately 4 billion years ago. Mount Elkins is a classic example of Napier orogeny. Napier orogeny is characterized by high-grade metamorphism and plate tectonics. The orogenic events that resulted in the formation of the Napier Complex (including Mount Elkins) have been dated to the Archean Eon. Radiometrically dated to as old as 3.8 billion years, some of the zircons collected from the orthogneisses of the Napier Complex are among the oldest rock specimens found on Earth. Billions of years of erosion and tectonic deformation have exposed the metamorphic rock core of these ancient mountains.

The oldest crustal components found to date in the Napier Complex appear to be of igneous derivation. This rock appears to have been overprinted by an ultra-high temperature metamorphic event (UHT) that occurred near the Archean-Proterozoic boundary. Using a lutetium-hafnium (Lu-Hf) method to examine garnet, orthopyroxene, sapphirine, osumilite and rutile from this UHT granulite belt, Choi et al determined an isochron age of 2.4 billion years for this metamorphic event. Using SHRIMPU–Pb zircon dating methodology, Belyatsky et al determined the oldest tectonothermal event in the formation of the Napier Complex to have occurred approximately 2.8 billion years ago.

Preservation of the UHT mineral assemblage in the analyzed rock suggests rapid cooling, with closure likely to have occurred for the Lu-Hf system at post-peak UHT conditions near a closure temperature of 800 °C. UHT granulites appear to have evolved in a low Lu-Hf environment, probably formed when the rocks were first extracted from a mantle profoundly depleted in lithophile elements. The source materials for the magmas that formed the Napier Complex were extremely depleted relative to the chondritic uniform reservoir (CHUR). These results also suggest significant depletion of the early Archean mantle, in agreement with the early igneous differentiation of the Earth that the latest core formation models require.

Ecology

Flora

To date, no flora has been observed at Mount Elkins.

Fauna

The following species have been sighted within 1.0 degrees of Mount Elkins:

Weather conditions

The Napier Mountains run northwest from Mount Elkins. To the east is a large valley formed by the Robert and Wilma Glaciers. To the northeast are the Seaton and Rippon Glaciers. All of these glaciers run into the King Edward Ice Shelf. Other notable terrain features in this area include the Beaver Glacier, located to the west of Mount King. Collectively, these terrain features significantly modify weather produced by synoptic scale systems. Dramatic changes can occur over short distances and in short time intervals.

Nearby terrain features

Place names within 1.0 degrees of Mount Elkins (Latitude 66°40.0'S Longitude 54°09.0'E)

History

Mount Elkins was first mapped by Norwegian cartographers from aerial photographs taken by the Lars Christensen Expedition, 1936–37, and named at that time Jökelen (The Glacier). It was remapped by ANARE from aerial photographs taken from an ANARE aircraft in 1956. The Napier Mountains were first visited by an ANARE survey party from Mawson Station in 1960. The survey party was led by Syd Kirkby and included Terence James Elkins.

Significance to mountaineers

The summit of Mount Elkins is higher than that of any mountain in Australia—including even Mount Kosciuszko (2,228 metres), which is one of the Seven Summits. Because of its remoteness it has not become a popular target for peak bagging.