A model of volcanogenic sedimentation in marginal basins

Document Type

Article

Date of Original Version

12-1-1984

Abstract

Marginal basins adjacent to oceanic island arcs receive volcaniclastic debris from the bordering volcanic arc, back-arc spreading centre, and, to a lesser degree, the remnant arc. The volcanic arc is volumetrically the most important source, with abundant volcaniclastics being produced by explosive subaerial and/or subaqueous eruptions and secondary erosion of the arc complex. Transport of material to the deeper parts of marginal basins occurs by passive settling through the water column or by a variety of sediment gravity flows generated by primary eruptions and secondary remobilization processes. Deposition of arc-derived material at the base of the arc flank produces thick volcaniclastic aprons and results in a marked asymmetry in the accumulation of volcanogenic sediment within basins. The apron facies are complex and not analogous to typical deep-sea fan systems because of the influence of arc volcanism on the nature and delivery of sediment to the deep sea. Back-arc spreading centres supply a small volume of deep-water hyaloclastites and hydrothermally derived volcanogenic sediments which are incorporated into the basal parts of sedimentary sequences. The dispersal and deposition of volcanogenic sediments are profoundly influenced by geological processes associated with marginal basin evolution such as back-arc spreading, faulting, and island-arc splitting. © 1984 The Geological Society.

Publication Title, e.g., Journal

Geological Society Special Publication

Volume

16

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