Redistribution of multi-phase particulate organic carbon in a marine shelf and canyon system during an exceptional river flood: Effects of Typhoon Morakot on the Gaoping River–Canyon system

• DOI: 10.1016/j.margeo.2015.02.013
• Publication Date: 2015-02-26T01:01:14Z
• Authors: Robert B. Sparkes; In-Tian Lin; Niels Hovius; Albert Galy; James T. Liu; Xiaomei Xu; Rick Yang
• Keywords: Submarine canyon; Deposition; Nepheloid layer

Volumetrically, turbidity currents are the prime suppliers of sediment to deep sea, and conveyors organic carbon from terrestrial biosphere submarine shelf into marine depositional basins. They result complex processes erosion, transport deposition that can be difficult study in detail. Here we present data Gaoping canyon system, off SW Taiwan, which was perturbed 2009 by addition flood deposits following Typhoon Morakot sampled gravity coring less than 2 months after event. We use different origins carbon, distinguished their nitrogen concentrations δ13C δ15N isotopic composition, compare contrast standard extreme sedimentological conditions. Using well-constrained end-members, results were de-convolved inputs metamorphic sedimentary fossil eroded within River basin, non-fossil matter. In upper Canyon, sedimentation is dominated highly-localised hyperpycnal input river washload slumps, each associated with extensive flooding Morakot, whilst experienced reworking hemi-pelagic sediments. A signal also found core-top a fine-grained sample over 20 km region normally deposition, showing an unusually large Conversely, just above thalweg contains 0.23 wt.% depth-averaged (37% TOC content) implying OC-dominated turbidites tightly constrained canyon. Hyperpycnal lead rapid efficient both sediments more permanent burial locations.