years and 200,000 ± 40,000 years for Baker Rocks, 2.7 ± 0.2million years and 450,000 ± 50,000 years for Cape Washington, 74,000 ± 110,000 years and 50,000 ± 20,000 years for Edmonson Point, less than 400,000 years for Markham Island, 745,000 ± 66,000 years for Harrows Peak, 1.368 ± 0.090million years for Pinkard Table, 1.55 ± 0.05million years, 431,000 ± 82,000 and 110,000 ± 70,000 years for Shield Nunatak, and 2.5 ± 0.1million years for Willows Nunatak. The northeastern parasitic cone formed after the bulk of the volcano and appears to be younger than the summit. Radiometric dating has shown that the appearance of a landform at Mount Melbourne is not indicative of its age; some well preserved vents are older than heavily eroded ones. On the other hand, a lack of proper margins of error and lack of details on which samples were dated has been problematic for radiometric dating efforts. Tephra Tephra found at the Allan Hills, in Dome C and in the Siple Dome ice cores may come from Mount Melbourne. Some marine tephra layers originally attributed to Mount Melbourne may instead come from Mount Rittmann, and many tephra layers in the area have compositions that do not match these from Mount Melbourne. There are additional tephra layers attributed to the volcano: Tephra layers less than 500,000 years old in the Frontier Mountain and Lichen Hills blue-ice areas have been attributed to volcanoes in the Mount Melbourne volcanic province. A tephra layer less than 30,000 years old in a sediment core from the Ross Sea has a composition indicating that it was erupted at Mount Melbourne. Its deposition has been used to infer that that part of the western Ross Sea was ice-free at that time. A tephra layer found in the Ross Sea has been interpreted as originating from an eruption of Mount Melbourne 9,700 ± 5,300 years ago. In the Talos Dome ice core record, two tephra layers emplaced 2,680 and 5,280 years ago have compositions similar to these of Mount Melbourne. Tephra layers at Siple Dome indicate eruptions at Mount Melbourne in 304CE, which deposited substantial amounts of sulfate on the ice sheet. A tephra layer at Siple Dome dated to 1810CE might have been erupted by Mount Melbourne, but its attribution is less certain than for the 304CE tephra. Mount Melbourne proper The Edmonson Point ignimbrite is a trachytic ignimbrite that crops out