Abstract

Positioned at the transition zone of the major hydrocarbon provinces of Browse and Bonaparte Basins, Ashmore Reef is built on what is thought to be Pleistocene antecedent topography. This mature, ovoid, shelf-edge reef experiences the seasonal oceanic influences of Indian Ocean and of the Indonesian-Through-Flow. The model for its development is derived from the post glacial (past 11,000 years) relative sea level curve, C14 dated facies changes and the reef growth phases extrapolated from the One Tree Reef model (Marshall & Davis 1982). A thorough visual examination of the reef was augmented with a series of 12 vibro-cores through algal-foraminiferal sand and coral, across the bioturbated platform. Changes in the lagoonal sediment facies were carbon dated giving dates ranging from 970 to 2020 (~70 years) BP. They indicated a major bio-facies change from robust vertical coral columns to an algal dominated reef crest and reef flats as sea level stabilised at ~2000 BP. Ashhmore Reef is presently characterised by high biodiversity and extensive coral growth, broad reef flats littered with coral boulders, and three vegetated cays. An extensive series of highly mobile and heavily bioturbated biogenic sand sheets adjoin two lagoons. Both are within a pronounced ovoid, algal-cemented, reef rim. The sediments comprised principally of Halimeda sp., coral fragments, foraminifera, molluscs and a range of coralline algae that infill the lagoon at up to 0.73 cm/yr. The three vegetated cays are capped with guano and all have wash-over deposits of pumice, wood, shell and coral.
Google map showing geographic bounding box with values North bound -12.0 East bound 124.0 West bound 123.0 South bound -13.0
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For information on acquiring this product,
please contact the Geoscience Australia Sales Centre via:

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Product Type/Sub Type

dataset - External Publication

Constraints

license
Creative Commons Attribution 3.0 Australia Licence

IP Owner

Commonwealth of Australia (Geoscience Australia)

Author(s)

Date (publication)

2001

Product Type

dataset

Topic Category

geoscientificInformation

Keywords

External Publication
sequence stratigraphy
morphology
palaeontology
Earth Sciences

Resource Language

English

Resource Character Set

utf8

Resource Security Classification

unclassified

Geographic Extent

North bound
-12.0
East bound
124.0
West bound
123.0
South bound
-13.0

Lineage

Unknown

Digital Transfer Options

onLine

Distributor

Role
distributor
Organisation Name
Geoscience Australia
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address

Metadata File Identifier

a05f7892-b627-7506-e044-00144fdd4fa6

Metadata Standard Name

ANZLIC Metadata Profile: An Australian/New Zealand Profile of AS/NZS ISO 19115:2005, Geographic information - Metadata

Metadata Standard Version

1.1

Metadata Date Stamp

2001-08-08

METADATA SECURITY CLASSIFICATION

unclassified

Metadata Contact

Role
pointOfContact
Organisation Name
Geoscience Australia
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address
Related Links
For information on acquiring this product,
please contact the Geoscience Australia Sales Centre via:

fax:
+61 2 6249 9960; or
phone:
1800 800 173 (within Australia);
 
+61 2 6249 9966 (outside Australia).

Please note that support hours are 9 am to 5 pm weekdays