New Zealand Journal of Marine and Freshwater Research abstracts
A budget for modern-Holocene sediment on the South Otago continental shelf
LIONEL CARTER
New Zealand Oceanographic Institute Department of Scientific and Industrial Research Private Bag, Kilbirnie, Wellington New Zealand
Abstract
A sediment budget for the South Otago continental shelf and coast, between Nugget Point and Otago Peninsula, reveals modern (post 6500 y) sediment input is dominated by the Clutha River (total 3.14 Mt y-'; Mt = 10" tonnes). Contributions from the Taieri River (0.6 Mt y
1), the adjacent Southland shelf (0.4 Mty~'), and the biogenic production of calcareous shell debris (0.25 Mty~') account for only 28% of the input. About half of the bedload (sand and gravel) reaching the Otago shelf is stored within a large nearshore sand wedge in the protected waters of Molyneux Bay, off the Clutha River. Bedload that escapes storage (1.1 Mty ') is transported north-eastwards to be deposited on beach and inner shelf environments just north of Otago Peninsula. Suspended load (mud) accounts for over half of the sediment input (2.33 Mt y~') and is nearly all transported from the study area to accumulate in north-easterly shelf and slope depocentres.
Keywords sediment budget; continental shelf; coast; sediment deposition; Holocene sediment wedge; bedload; suspended load; Clutha River; Otago; South Island
AVtv Zealand Journal of Marine and Freshwater Research, 1986, Vol. 20 : 665-676 Received 15 July 1985; accepted 10 March 1986
PDF file of entire paper: medium quality (838K); (scanned from paper original: notes about this process)
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