The age and mode of formation of Gaussberg, Antarctica
Titel:
The age and mode of formation of Gaussberg, Antarctica
Auteur:
Tingey, R. J. McDougall, Ian Gleadow, A. J. W.
Verschenen in:
Australian journal of earth sciences
Paginering:
Jaargang 30 (1983) nr. 1-2 pagina's 241-246
Jaar:
1983-07
Inhoud:
Circumstantial evidence indicates that Gaussberg, an isolated, 370 m high volcanic cone on the Antarctic coast at 57°S, 89°E, is the product of subglacial eruption. The vesicular, highly potassic leucitite, of which Gaussberg is composed, has been dated by K-Ar and fission-track methods, the former being applied to leucite concentrates, the latter to glassy leucitite from the ropy-textured, outer rind of a pillow-like structure. The K-Ar geochronology yields an average date of 56 000 ± 5000 years, jwhich is interpreted as defining the time of Gaussberg's formation. The fission-track work yields a less precise date, which supports the K-Ar age estimate. These new age determinations indicate that previously published K-Ar age determinations of 20 Ma and 9 Ma for Gaussberg should be rejected.