1999). During the final stages of the transgression, when
present sea-levels were reached (or exceeded), reefs along
the outer-shelf margin caught up with sea-level, leading to
closure of the high energy window. Numerous headlands
were incorporated into the coast during the final stage of
the transgression resulting in the development of a much
more indented coastline. This facilitated the trapping of
longshore-driven sediments and the development and
progradation of extensive coastal beach ridge sequences.
Impacts of a high energy “window” at the reef and
reef island scale
Whilst the concept of a Holocene high energy window
is perhaps best known from discussions regarding its
influence on the GBR shelf, the concept has also been
considered in relation to different phases of reef and reef
island development. This is evident, for example, along
reef-fronted coastlines and narrow shelves where reef
growth appears to have lagged behind sea-level. Subsequent accumulation of barrier-type reefs up to sea-level
resulted in a closure of these more localized high energy
windows, leading to a transition in the nature and character of reef-building to leeward of the main reef structures.
Examples include those reefs described from the Ryukyu
Islands (Kan et al., 1997), Palau (Kayanne et al., 2002),
and Madagascar (Camoin et al., 2004). The concept of
high energy phases has also been discussed as an important potential control on reef island building. Kench et al.
(2005), for example, have invoked periods of higher
wave energy and associated sediment transport to nodal
sites of accumulation, as an important control on the
development of reef islands in the Maldives. Similar
views have also been discussed in relation to a range of
reef islands in the Pacific (Nunn, 1997) and on the
GBR (Hopley, 1984).
Holocene High Energy Window, Figure 2 Schematic diagram showing the influence of a Holocene high energy window on the
development of shelf environments based on the central Great Barrier Reef region of Australia (stage concepts developed from
Hopley, 1984; Hopley et al., 2007).
560
HOLOCENE HIGH ENERGY WINDOW
present sea-levels were reached (or exceeded), reefs along
the outer-shelf margin caught up with sea-level, leading to
closure of the high energy window. Numerous headlands
were incorporated into the coast during the final stage of
the transgression resulting in the development of a much
more indented coastline. This facilitated the trapping of
longshore-driven sediments and the development and
progradation of extensive coastal beach ridge sequences.
Impacts of a high energy “window” at the reef and
reef island scale
Whilst the concept of a Holocene high energy window
is perhaps best known from discussions regarding its
influence on the GBR shelf, the concept has also been
considered in relation to different phases of reef and reef
island development. This is evident, for example, along
reef-fronted coastlines and narrow shelves where reef
growth appears to have lagged behind sea-level. Subsequent accumulation of barrier-type reefs up to sea-level
resulted in a closure of these more localized high energy
windows, leading to a transition in the nature and character of reef-building to leeward of the main reef structures.
Examples include those reefs described from the Ryukyu
Islands (Kan et al., 1997), Palau (Kayanne et al., 2002),
and Madagascar (Camoin et al., 2004). The concept of
high energy phases has also been discussed as an important potential control on reef island building. Kench et al.
(2005), for example, have invoked periods of higher
wave energy and associated sediment transport to nodal
sites of accumulation, as an important control on the
development of reef islands in the Maldives. Similar
views have also been discussed in relation to a range of
reef islands in the Pacific (Nunn, 1997) and on the
GBR (Hopley, 1984).
Holocene High Energy Window, Figure 2 Schematic diagram showing the influence of a Holocene high energy window on the
development of shelf environments based on the central Great Barrier Reef region of Australia (stage concepts developed from
Hopley, 1984; Hopley et al., 2007).
560
HOLOCENE HIGH ENERGY WINDOW