Dampier Ridge, Tasman Sea, as a stranded continental fragment
Titel:
Dampier Ridge, Tasman Sea, as a stranded continental fragment
Auteur:
McDougall, I. Maboko, M. A. H. Symonds, P. A. McCulloch, M. T. Williams, I. S. Kudrass, H. R.
Verschenen in:
Australian journal of earth sciences
Paginering:
Jaargang 41 (1994) nr. 5 pagina's 395-406
Jaar:
1994-10
Inhoud:
Dredging of the Dampier Ridge recovered small fragments of granite, gabbro and sandstone. Dating of the igneous samples by the U-Pb, K-Ar and Rb-Sr methods yielded precise ages mainly in the range 250 to 270 Ma, mid-Permian. An imprecise Sm-Nd mineral age of ∼ 310 Ma might reflect slightly earlier emplacement of the gabbro. A granitic fragment has a composition approximating that of a minimum melt. Taken together with the Late Palaeozoic emplacement ages and other geochemical and geophysical data, the evidence strongly supports the conclusion that the Dampier Ridge is a continental fragment, formerly part of eastern Australia, with its present location a consequence of continental rifting and opening of the Tasman Basin by sea-floor spreading.