Late Quaternary occurrences of Zoophycos in a high sedimentation rate setting on the continental margin off southwestern Taiwan: Implications for trace maker ecology
Journal
Palaeogeography, Palaeoclimatology, Palaeoecology
Journal Volume
690
Start Page
113681
ISSN
0031-0182
Date Issued
2026-05
Author(s)
Pillutla, Radha Krishna
Lin, Andrew Tien-Shun
Yeh, Jen-Chu
Ratzov, Gueorgui
Babonneau, Nathalie
Hsu, Shu-Kun
Lallemand, Serge
Tseng, Wan-Ling
Abstract
In Quaternary deep marine deposits, the trace-fossil Zoophycos is ubiquitous in low sedimentation rate settings (∼10 cm ky−1) below about 1000 m water depth. The Zoophycos-producer's preference for environments with strong seasonal swings in food flux, and the fact that the material in the trace fossil is both younger and more organic‑carbon rich than ambient sediment, indicates that Zoophycos represents a cache behaviour, where food is squirreled away during high food fluxes for use during leaner times. The unusual occurrence of Zoophycos in a high-sedimentation rate setting (>100 cm ky−1) dominated by homogenite deposition, reported here from the continental margin of Taiwan, therefore raises questions about the ethology and environmental preferences of the producer. Four main hypotheses are tested: (1) opportunistic colonization, (2) event dispersal, (3) response to post-homogenite depositional conditions, and (4) response to climate events. An opportunistic colonization of the homogenite and an event dispersal of Zoophycos-producers from upslope locations can effectively be refuted by the fact that Zoophycos spreiten are found not only in the upper parts of the homogenites, but also in the lower parts of the overlying hemipelagic sediment. No correlation between the occurrence of Zoophycos and known events or rearrangements of the SE Asian climate system could be found, effectively refuting the climate-response hypothesis. Consequently, the Zoophycos in the uppermost parts of the homogenites and the lowermost parts of the hemipelagites can best be explained by temporary phases of low sedimentation rates prevailing after the deposition of the homogenites, forming a wide, quasi-horizontal surface in the perched basin limiting the sediment influx to the basin, thus favouring a cache behaviour by the producer.
Subjects
Accretionary wedge
Event deposits
Homogenite
Taiwan
Trace fossil
Zoophycos
Publisher
Elsevier BV
Type
journal article