Authors / CoAuthors
Ryan, D.A. | Brooke, B. | Collins, L. | Bickers, A. | Baxter, K.
Abstract
The Recherche Archipelago lies within the westernmost reaches of the Great Australian Bight, a large cool-water carbonate depositional province on the southern Australian margin. The inner shelf of the archipelago comprises numerous islands, typically comprising Proterozoic granites, which protrude from the shelf of mainly recent carbonate sediments. The area is influenced by extreme Southern Ocean swell energy, which results in a typically wave-abraded inner shelf, and sediment deposition mainly on the mid- to outer shelf. For Esperance Bay, a large shallow-water embayment within the archipelago, we examined the relationships between bottom sediments, geomorphology and the distribution of biotic habitats by integrating multibeam sonar, underwater video and sediment grab sample information. Major benthic habitats, such as seagrass beds, rhodolith beds, rocky reefs and mobile sand sheets are characterised in terms of their sea bed morphology, sedimentology and bioclastic composition. The littoral zone comprises mature quartz sand dominated by seagrasses, whereas the mainly carbonate-dominated shelf sediments are typically coarse gravely sands, and contain significant quantities of granitic material that is accumulating in areas of low wave exposure, typically behind the rocky islands. Bioclasts are dominated by red algal, bryozoan and foraminiferal components, as well as relict material. Sediment lags and calcarenite reefs occur in areas of high wave exposure, often with significant covers of macro-algae and sponges. The abundance of sediment producing organisms such as shallow-water rhodoliths and the presence of large-scale mobile sediment bedforms suggests that due to the influence of the rocky islands, the localised production and accumulation of carbonate sediments in the Recherche Archipelago is significantly greater than that observed in other parts of the Great Australian Bight inner shelf.
Product Type
nonGeographicDataset
eCat Id
61704
Contact for the resource
Custodian
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
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- External PublicationArticle
- ( Theme )
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- carbonate
- ( Theme )
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- coasts
- ( Theme )
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- environmental
- ( Theme )
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- morphology
- ( Theme )
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- mapping
- ( Theme )
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- marine
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- AU-WA
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Earth Sciences
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- Published_Internal
Publication Date
2004-11-01T00:00:00
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unknown
Topic Category
geoscientificInformation
Series Information
Lineage
Unknown
Parent Information
Extents
[-34.2, -33.8, 121.6, 122.2]
Reference System
Spatial Resolution
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Associations
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Source data not available.