Recent Bioturbation In The Deep South China Sea: A Uniformitarian Ichnologic Approach

• DOI: 10.2110/palo.2007.p07-096r
• Publication Date: 2008-09-12T20:18:17Z
• Authors: A. Wetzel
• Keywords: Bioturbation

Four environmental provinces are distinguished in the deep South China Sea based on ichna and their relationship to Pinatubo 1991 ash accumulation. Scolicia ichnofabrics along Philippine Islands sand-prone, greenish, oxygen-deficient deposits 3500 m water depth. Abundance size of appear be related quantity quality benthic food, respectively. producers intensely bioturbate ash; below this level, Phycosiphon, Planolites, Thalassinoides may occupy different tiers. In mud-prone Palaeophycus, Thalassinoides, local Zoophycos (including Spirophyton-like Zoophycos) present. Manila Trench, turbidites sparsely bioturbated. To west, found slowly deposited, deeply oxidized sediments containing little organic matter; Fe- Mn-oxides lead induration. The area west 118E is affected by upwelling intense wind mixing, where Nereites feed preferably just above redox boundary. Following blooms, however, temporary surface feeding documented burrows. high food content vertical movements probably prevented production graphoglyptids. Below level Planolites bioturbated some degree hyperpycnites provide a soft layer particular Philippines. Where such lacking, nearly unbioturbated. ample matter reaches seafloor, trails have been observed, especially Philippines slope mixing.