Turnpike Bluff

Turnpike Bluff (80°44′S 30°4′W) is a conspicuous rock formation in the Shackleton Mountains of Antarctica.^[1]

Turnpike Bluff
Highest point
Coordinates	80°44′S 30°4′W

Exploration

Otter Highlands to the southwest of Blaiklock Glacier. Turnpike Bluff in southwest

First mapped in 1957 by the Commonwealth Trans-Antarctic Expedition, and so named because it marks entry to a crevassed area of Recovery Glacier through which the Expedition's vehicles had difficulty in passing on their journey from Shackleton Base to the South Pole in 1957.^[1]

Location

Turnpike Bluff is in the south of the Otter Highlands, to the north of the Recovery Glacier.^[2] It lies five nautical miles (9 km) southwest of Mount Homard, at the southwest extremity of the Shackleton Range.^[1]

Geology

The Turnpike Bluff Group is a sedimentary sequence of rocks exposed on the south flank of the Shackleton Range. The sequence includes basal clastics and quartzite, followed by carbonate-bearing clastics with Riphean age stromatolite colonies, and capped by over 1 km of greywacke and quartzitic arenite, alternating with pelite. The sequence is underlain unconformably by an Archean granitoid basement (1400 Ma). Metamorphism occurred at 526 Ma.^[3] The group contains four formations, named after Wyeth Heights, Stephenson Bastion, Flett Crags and Mount Wegener.^[4] These are features along the southern margin of the Shackleton Mountains, from west to east.^[2]