Citation

Geoscience Australia provides most of its products for free under a Creative Commons Attribution 3.0 Australia Licence. We only require that you reference the use of our data or information using the following citation:
Marshall, J.F., 1980. Continental shelf sediments: southern Queensland and northern New South Wales. Scale 1:1000000. Bulletin  207. Bureau of Mineral Resources, Geology and Geophysics, Canberra.

Abstract

Sands are predominant over the entire continental shelf, and mud is absent or only a minor component of the sediments. The amount of gravel, largely biogenic, is high in some places, but it has a scattered distribution. The amount of carbonate on the outer shelf is relatively low as a result of the formation of authigenic minerals. The amount and type of carbonate material have a substantial bearing on the grainsize and sorting of the sediments. The terrigenous component of the sediments is dominated by quartz, and there are usually only minor amounts of feldspar and rock fragments. Four typesof quartz grains have been identified on the basis of roundness, sorting, and grainsize. These quartz types are believed to be related to various sources including beach and fluvial deposits. Skeletal carbonate components include mainly foraminifera, molluscs, Bryozoa, echinoderms, and calcareous red algae. Intraclasts with either micrite or sparite cement are common and various types of carbonate cements have developed, predominantly within the chambers of organisms. Authigenic components of the shelf sediments consist of glauconite, goethite, and apatite. These are most abundant on the outer shelf, especially between 29° and 32°S. Goethite and glauconite most commonly fill the chambers of organisms, especially foraminifera, and apatite is present within the matrix of nodules and boulders of cemented nodules. Most of the sediments on the shelf are considered to be relict.Sediments were analysed for iron, arsenic, phosphorus, and titanium. High iron values, up to 25 percent F e 2 O s , are present on the outer shelf between 29° and 32°S.These high values are related to sediments which have high concentrations of goethite and glauconite. High arsenic values (up to 390 ppm As) are associated with these sediments, and also with the phosporites. Phosphorus values of about 6-10 percent P 2 0 5 characterise nodules from the same area. Most titanium values are less than 0.5percent TiOo. Factor analysis indicates a good correlation between Fe, As, and P 2 0 5 . The iron-rich sediments on the outer shelf are considered to have formed by the oxidation of glauconite, resulting in the formation of hydrated iron oxides. Arsenic and to some extent phosphorus have been adsorbed onto the hydrated iron oxides. The phosporites are considered to have formed in two stages: (1) direct precipitation of carbonate- apatite between mineral grains, and (2) subsequent replacement of micritic carbonate.
Google map showing geographic bounding box with values North bound -25.0 East bound 156.0 West bound 152.0 South bound -32.0
Downloads
For information on acquiring this product,
please contact Geoscience Australia Client Services via:

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

Product Type/Sub Type

dataset - GA Publication - Bulletin

Constraints

license
Creative Commons Attribution 3.0 Australia Licence

IP Owner

Commonwealth of Australia (Geoscience Australia)

Author(s)

Date (publication)

1980

Product Type

dataset

Topic Category

geoscientificInformation

Keywords

GA Publication
Bulletin
Earth Sciences

Resource Language

English

Resource Character Set

utf8

Resource Security Classification

unclassified

Geographic Extent

North bound
-25.0
East bound
156.0
West bound
152.0
South bound
-32.0

Lineage

Unknown

Digital Transfer Options

onLine

DISTRIBUTION Format

pdf

Distributor

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

Metadata File Identifier

a05f7892-7fa4-7506-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

1996-10-29

METADATA SECURITY CLASSIFICATION

unclassified

Metadata Contact

Role
pointOfContact
Organisation Name
Geoscience Australia
City
Canberra
Administrative Area
ACT
Postal Code
2601
Country
Australia
Email Address
Downloads
For information on acquiring this product,
please contact Geoscience Australia Client Services via:

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