Tracing the source of sediment and phosphorus into the Great Barrier Reef lagoon

Details Tracing the source of sediment and phosphorus into the Great Barrier Reef lagoon Tracing the source of sediment and phosphorus into the Great Barrier Reef lagoon

May 2003

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003e%26psl.210..249m&link_type=abstract

Earth and Planetary Science Letters, Volume 210, Issue 1-2, p. 249-258.

Computer Science

3

Sediment Phosphorus Tracing, Great Barrier Reef, Degradation, Neodymium-Strontium Isotopes

Scientific paper

Neodymium and strontium isotopic systematics show that terrestrial phosphorus (P) entering the inner Great Barrier Reef (GBR) is dominated by the transport and dispersal of fine-grained basaltic soils. Soils derived from alkali basalts have high total P (3000-4000 mg/kg) and distinctive 143Nd/144Nd isotopic signatures (ɛNd~+3 to +5), while the more common Palaeozoic granitic/metamorphic soils have much lower total P (300-600 mg/kg) and 143Nd isotopic signatures (ɛNd~-8). The nearshore environment (<5 km from the coast) is dominated by coarse-grained, granitic-derived fluvial detritus, while >20 km from the coast, carbonate-rich sediments with increasing contributions from basaltic components become more important. In the offshore sites adjacent to coral reefs, it is shown that basalt-derived sediments can account for >90% of the terrestrial P, although making up less than half of the total terrigenous detritus. Equilibrium phosphorus concentration measurements on the marine sediments indicate that P enters the GBR lagoon via a two-stage process. Firstly, during episodic flood events, P is transported into the GBR lagoon on P-retentive fine-grained suspended sediments, with only minor desorption of P occurring in the low-salinity flood plumes. Desorption of P mainly occurs over longer timescales, predominantly in regions of sediment anoxia, with release of PO43- directly into marine pore waters probably via reduction of ferric phosphates, and subsequent release into the water column by re-suspension. This process causes P depletion of the re-deposited sediments.
Present address: Geology Department, University of Otago, Dunedin, New Zealand.

Affiliated with

Also associated with

No associations

Rating

Tracing the source of sediment and phosphorus into the Great Barrier Reef lagoon does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Tracing the source of sediment and phosphorus into the Great Barrier Reef lagoon, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Tracing the source of sediment and phosphorus into the Great Barrier Reef lagoon will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1523577