subject to a shallow water energy regime for most of the
time that they have been growing; growth therefore
reflects this. Different reef growth strategies reflect the
interaction of substrate depth, sea-level rate of change,
and coral growth rate. A major change in growth and
bio- and sedimentary facies occurs when the growing reef
approaches sea level – the formation of algal and coral
flats reflect biofacies changes and sand sheets and rubble
flats reflect sedimentary facies changes.
Five broad carbonate facies are recognized; three are
framework facies and two are detrital facies:
1. Coralline algal facies. These are laminated crusts,
often centimeters thick and/or encrustations on
branching or massive corals. The facies is best developed on windward margins, but encrusting corallines
coat most dead or dying surfaces in all intertidal reef
environments.
2. Branching coral facies. Growth form varies with depth,
light, and energy. In shallow water, variations in energy
define wide differences in species composition and
diversity. Water-depth changes produce similar compositional variations.
3. Massive (head) facies. As with the branching forms,
water depth and energy define diversity.
4. Sand facies. These are usually medium to coarse sand
comprise coral and corallines, benthic foraminifera,
and minor Halimeda. Forms large sand sheets between
coral flats and lagoons and also infills lagoons.
5. Rubble facies. These are comprised of massive, platey,
and branching corals. Produced either by in situ collapse (in lagoons) or by energy-related breakage and
transport.
Three growth models are presented, two for mid-shelf
platform reefs (One Tree and Stanley Reefs) and one for
outer shelf barrier reefs (Ribbon 5). It is concluded that
most Holocene reefs in the Great Barrier Reef, with the
possible exception of fringing reefs, have undergone the
same basic processes of growth from an antecedent platform to sea level and then growth controlled by the direction and energy of the impinging energy. This is common
in the three models defined above. The models are however of two totally different reef growth environments –
the shelf edge and the mid-shelf platforms. They are
almost two end members with different characteristics
produced by the same parameters. In both cases, however,
the dominant control is substrate, to produce a linear outer
shelf feature and crescentic/lagoonal mid-shelf features.
However, in the mid-shelf reefs, patterns of reef development are recognized which have specific characteristics
which appear to overlap and which are probably related
to the depth, size, and shape of the Pleistocene substrate,
the timing of reaching sea level, and the total energy
within the physical environment. In an evolutionary sense,
reefs can be judged to be juvenile, mature, and senile.
Thus, crescentic reefs may grow into lagoonal platform
reefs and eventually into flat-topped platforms with live
coral growth only around the perimeter. Most importantly,
the rate of progress in this evolution is a function of the
size and depth of the platform and the energy impinging
in the still stand system. Thus, small reefs (Wreck in the
Capricorns) will progress to senility rapidly while Stanley
(large reef) is yet to achieve maturity. Evolutionary progression may occur through more than one highstand
growth phase. Predicted future climate changes will accelerate evolutionary progression.
Bibliography
Brachert, T. C., Betzler, C., Davies, P. J., and Feary, D. A., 1993.
Climate change as a control on carbonate platform development
(Eocene-Miocene, ODP-Leg 133, N.E.–Australia). In
McKenzie, J. A., Davies, P. J., Palmer-Julson, A., and Sarg
J. F. (eds.), Proceedings. Ocean Drilling Program, Scientific
Results, College Station, TX: Texas A. and M. University,
p. 133.
Braga, J. C., and Aguirre, J., 1997. Coralline algae indicate Pleistocene evolution from deep open platform to outer barrier reef
environments in the northern Great Barrier Reef margin. Coral
Reefs, 23, 547–558.
Braithwaite, C. J. R., Dalmasso, H., Gilmour, M. A., Harkness,
D. D., Henderson, G. M., Kay, R. L. F., Kroon, D., Montaggioni,
L. F., and Wilson, P. A., 2004. The Great Barrier Reef: the chronological record from a new borehole. Journal Sedimentary
Research, 74, 298–310.
Chaproniere, G. C. H., 1984. Oligocene and Miocene larger foraminifera from Australia and New Zealand. Bureau of Mineral
Resources Australia Bulletin, 188, 98.
Davies, P. J., 1983. Reef Growth. In Barnes, D. J. (ed.), Perspectives
on Coral Reefs. Brian Clouston, Canberra: Australian Institute of
Marine Science, 69–106.
Davies, P. J., Braga, J. C., Lund, M., and Webster, J. M., 2004. Holocene deep water algal buildups on the Eastern Australian shelf.
Palaios, 598.
Davies, P. J., and Hopley, D., 1983. Growth facies and growth rates
of Holocene reefs in the Great Barrier Reef. Bureau Mineral
Resources Journal Australian Geology and Geophysics, 8,
237–251.
Davies, P. J., and Hughes, H., 1983. High energy reef and terrigenous sedimentation, Boulder Reef, Great Barrier Reef. Bureau
Mineral Resources Journal Australian. Geology and Geophysics, 8, 201–210.
Davies, P. J., and Marshall, J. F., 1980. A model of epicontinental
reef growth. Nature, 287, 37–38.
Davies, P. J., Marshall, J. F., and Hopley, D., 1985. Relationships
between reef growth and sea-level rise in the Great Barrier Reef.
In Proceedings of the Fifth International Coral Reef Symposium,
Tahiti, pp. 95–103.
Davies, P. J., and McKenzie, J. A., 1993. Controls on the pliocenepleistocene evolution of the northeastern Australian continental
margin. In McKenzie, J. A., Davies, P. J., Palmer-Julson, A.,
and Sarg J. F. (eds.), Proceedings Ocean Drilling Program, Scientific Results, p. 133. College Station, TX, Texas A. and M.
University.
Davies, P. J., McKenzie, J. A., Palmer-Julson, A., and Sarg, J. F.,
1991. In Proceedings of Ocean Drilling Program, Initial
Reports, p. 133. College Station, TX, Texas A. and M.
University.
Davies, P. J., and Montaggioni, L., 1985. Reef growth and sea-level
change: the environmental signature. In Proceedings of the Fifth
International Coral Reef Symposium, Tahiti, pp. 477–515.
Davies, P. J., and Peerderman, F., 1998. The origin of the Great Barrier Reef – the impact of Leg 133 drilling. In Camoin, G. F., and
532
GREAT BARRIER REEF: ORIGIN, EVOLUTION, AND MODERN DEVELOPMENT
time that they have been growing; growth therefore
reflects this. Different reef growth strategies reflect the
interaction of substrate depth, sea-level rate of change,
and coral growth rate. A major change in growth and
bio- and sedimentary facies occurs when the growing reef
approaches sea level – the formation of algal and coral
flats reflect biofacies changes and sand sheets and rubble
flats reflect sedimentary facies changes.
Five broad carbonate facies are recognized; three are
framework facies and two are detrital facies:
1. Coralline algal facies. These are laminated crusts,
often centimeters thick and/or encrustations on
branching or massive corals. The facies is best developed on windward margins, but encrusting corallines
coat most dead or dying surfaces in all intertidal reef
environments.
2. Branching coral facies. Growth form varies with depth,
light, and energy. In shallow water, variations in energy
define wide differences in species composition and
diversity. Water-depth changes produce similar compositional variations.
3. Massive (head) facies. As with the branching forms,
water depth and energy define diversity.
4. Sand facies. These are usually medium to coarse sand
comprise coral and corallines, benthic foraminifera,
and minor Halimeda. Forms large sand sheets between
coral flats and lagoons and also infills lagoons.
5. Rubble facies. These are comprised of massive, platey,
and branching corals. Produced either by in situ collapse (in lagoons) or by energy-related breakage and
transport.
Three growth models are presented, two for mid-shelf
platform reefs (One Tree and Stanley Reefs) and one for
outer shelf barrier reefs (Ribbon 5). It is concluded that
most Holocene reefs in the Great Barrier Reef, with the
possible exception of fringing reefs, have undergone the
same basic processes of growth from an antecedent platform to sea level and then growth controlled by the direction and energy of the impinging energy. This is common
in the three models defined above. The models are however of two totally different reef growth environments –
the shelf edge and the mid-shelf platforms. They are
almost two end members with different characteristics
produced by the same parameters. In both cases, however,
the dominant control is substrate, to produce a linear outer
shelf feature and crescentic/lagoonal mid-shelf features.
However, in the mid-shelf reefs, patterns of reef development are recognized which have specific characteristics
which appear to overlap and which are probably related
to the depth, size, and shape of the Pleistocene substrate,
the timing of reaching sea level, and the total energy
within the physical environment. In an evolutionary sense,
reefs can be judged to be juvenile, mature, and senile.
Thus, crescentic reefs may grow into lagoonal platform
reefs and eventually into flat-topped platforms with live
coral growth only around the perimeter. Most importantly,
the rate of progress in this evolution is a function of the
size and depth of the platform and the energy impinging
in the still stand system. Thus, small reefs (Wreck in the
Capricorns) will progress to senility rapidly while Stanley
(large reef) is yet to achieve maturity. Evolutionary progression may occur through more than one highstand
growth phase. Predicted future climate changes will accelerate evolutionary progression.
Bibliography
Brachert, T. C., Betzler, C., Davies, P. J., and Feary, D. A., 1993.
Climate change as a control on carbonate platform development
(Eocene-Miocene, ODP-Leg 133, N.E.–Australia). In
McKenzie, J. A., Davies, P. J., Palmer-Julson, A., and Sarg
J. F. (eds.), Proceedings. Ocean Drilling Program, Scientific
Results, College Station, TX: Texas A. and M. University,
p. 133.
Braga, J. C., and Aguirre, J., 1997. Coralline algae indicate Pleistocene evolution from deep open platform to outer barrier reef
environments in the northern Great Barrier Reef margin. Coral
Reefs, 23, 547–558.
Braithwaite, C. J. R., Dalmasso, H., Gilmour, M. A., Harkness,
D. D., Henderson, G. M., Kay, R. L. F., Kroon, D., Montaggioni,
L. F., and Wilson, P. A., 2004. The Great Barrier Reef: the chronological record from a new borehole. Journal Sedimentary
Research, 74, 298–310.
Chaproniere, G. C. H., 1984. Oligocene and Miocene larger foraminifera from Australia and New Zealand. Bureau of Mineral
Resources Australia Bulletin, 188, 98.
Davies, P. J., 1983. Reef Growth. In Barnes, D. J. (ed.), Perspectives
on Coral Reefs. Brian Clouston, Canberra: Australian Institute of
Marine Science, 69–106.
Davies, P. J., Braga, J. C., Lund, M., and Webster, J. M., 2004. Holocene deep water algal buildups on the Eastern Australian shelf.
Palaios, 598.
Davies, P. J., and Hopley, D., 1983. Growth facies and growth rates
of Holocene reefs in the Great Barrier Reef. Bureau Mineral
Resources Journal Australian Geology and Geophysics, 8,
237–251.
Davies, P. J., and Hughes, H., 1983. High energy reef and terrigenous sedimentation, Boulder Reef, Great Barrier Reef. Bureau
Mineral Resources Journal Australian. Geology and Geophysics, 8, 201–210.
Davies, P. J., and Marshall, J. F., 1980. A model of epicontinental
reef growth. Nature, 287, 37–38.
Davies, P. J., Marshall, J. F., and Hopley, D., 1985. Relationships
between reef growth and sea-level rise in the Great Barrier Reef.
In Proceedings of the Fifth International Coral Reef Symposium,
Tahiti, pp. 95–103.
Davies, P. J., and McKenzie, J. A., 1993. Controls on the pliocenepleistocene evolution of the northeastern Australian continental
margin. In McKenzie, J. A., Davies, P. J., Palmer-Julson, A.,
and Sarg J. F. (eds.), Proceedings Ocean Drilling Program, Scientific Results, p. 133. College Station, TX, Texas A. and M.
University.
Davies, P. J., McKenzie, J. A., Palmer-Julson, A., and Sarg, J. F.,
1991. In Proceedings of Ocean Drilling Program, Initial
Reports, p. 133. College Station, TX, Texas A. and M.
University.
Davies, P. J., and Montaggioni, L., 1985. Reef growth and sea-level
change: the environmental signature. In Proceedings of the Fifth
International Coral Reef Symposium, Tahiti, pp. 477–515.
Davies, P. J., and Peerderman, F., 1998. The origin of the Great Barrier Reef – the impact of Leg 133 drilling. In Camoin, G. F., and
532
GREAT BARRIER REEF: ORIGIN, EVOLUTION, AND MODERN DEVELOPMENT