Electron microprobe characterization of ash layers in sedimentsfrom the central Bransfield basin (Antarctic Peninsula): evidencefor at least two volcanic sources

[摘要] Bransfield Strait, a narrow active rift with three submarine basins, separates the South ShetlandIslands from northern Antarctic Peninsula. Volcanism in Bransfield Strait commenced prior to 0.75 Ma andcontinues, with recent subaerial eruptions at Deception, Bridgeman and Penguin islands, submarinehydrothermal activity and numerous young basaltic seamounts located along the rift axis. Gravity cores werecollected from five locations within the central Bransfield basin. Diatomaceous mud interbedded withterrigenous detritus and discrete ash layers up to 10 cm thick are the commonest sediment types in all the cores. The major element compositions of glass shards within the ash layers are, apart from the uppermostlayer, compositionally similar to pyroclastic units preserved on Deception Island, a young (

[学科分类] 自然科学（综合）