Geoscience Reference
In-Depth Information
Gagan, M.K., Johnson, D.P. & Carter, R.M. (1988) The Cyclone Winifred storm bed, central Great Barrier Reef
shelf, Australia.
Journal of Sedimentary Petrology
58
, 845-56.
Gagan, M.K., Chivas, A.R. & Herczeg, A.L. (1990) Shelf-wide erosion, deposition, and suspended sediment
transport during Cyclone Winifred, central Great Barrier Reef, Australia.
Journal of Sedimentary Petrology
60
, 456 -70.
Forristall, G.Z., Hamilton, R.C. & Cardone, V.J. (1977) Continental shelf currents in Tropical Storm Delia:
observations and theory.
Journal of Physical Oceanography
7
, 532- 46.
Hopley, D. (1982)
The Geomorphology of the Great Barrier Reef: Quaternary Development of Coral Reefs
.
Wiley-Interscience, New York.
Hubbard, D.K. (1992) Hurricane-induced sediment transport in open-shelf tropical systems - an example from
St. Croix, U.S. Virgin Islands.
Journal of Sedimentary Petrology
62
, 949- 60.
Jones, M.R. (1985)
Quaternary Geology and Coastline Evolution of Trinity Bay, North Queensland
.
Publication 386, Geological Survey of Queensland, Brisbane, 27 pp.
Larcombe, P. & Carter, R.M. (2004) Cyclone pumping, sediment partitioning and the development of the Great
Barrier Reef shelf system: a review.
Quaternary Science Reviews
23
, 107-35.
Nott, J. & Hayne, M. (2001) High frequency of 'super-cyclones' along the Great Barrier Reef over the past
5000 years.
Nature
413
, 508 -12.
10.2.3.3 Wave-influenced shelves
of 30 m yr
−1
, and the sand is formed into large
dunes in places. To seawards, at depths beneath
c
. 60 m, lies a gravel and sand facies related
to early Holocene lower sea-level, the southern
sandy portion of which is being slowly reworked
by modern storm-driven processes into sand
ribbons, aligned along the shelf.
The Southern Ocean generates numerous power-
ful storms, and shelves to its north are subject to
the impact of swell waves. On the south-facing
Lacepede shelf, South Australia, sedimentary
facies are generally arranged in zones parallel to
the coast and mud is deposited only below depths
of 140 m ( James et al. 1992). The sedimentary
regime of the South Otago shelf (Fig. 10.6) located
on the south-east of South Island, New Zealand,
can be characterized as being dominated by
the action of swell waves plus storms (Carter
et al. 1985; Carter & Carter 1986). Here, swell
waves typically mobilize the sandy sea-bed down
to depths of 30 m, but a combination of the
regional Southland Current, locally strong tides,
plus storms, is required to mobilize fine sand to
depths of
c
. 75 m. The grain size of the modern
terrigenous inner-shelf sand wedge, which com-
menced deposition in the past 6500 yr, fines
seawards and northwards, with higher mud and
biogenic content at its seawards edge. A complex
mineralogy and suite of heavy minerals, com-
bined with textural trends and its overall mor-
phology clearly indicate net northward sediment
transport. On the inner shelf, the northern front
of the sand wedge has advanced northwards dur-
ing the Holocene highstand at an average rate
10.2.3.4 River-influenced shelves
Some continental shelves have their oceano-
graphic and sedimentary regimes heavily
influenced by river input, in the form of large
volumes of freshwater and/or very high rates
of sediment input (e.g. the Yellow Sea-East
China Sea, Amazon). With such large systems,
riverine, estuarine and shelf processes merge
across the shelf and, with such muddy systems,
fluid mud processes close to the sea bed become
important (Kineke et al. 1996) along with fac-
tors such as sediment oxygen concentration,
organic content and bioturbation ( Johnson &
Baldwin 1996).
The Amazon shelf receives
c
. 1.2
10
9
tyr
−1
of land-derived sediment from the Amazon River
(Milliman & Meade 1983; Dunne et al. 1988;
Allen 1997), which is distributed more than
100 km across and 400 km northwards along
the shelf, and down to depths of 70 m. Sediment
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