Seafloor environments of the northern Lord Howe Rise, Eastern Australia: Organic carbon and nitrogen concentrations and isotopes in seabed sediments.  

Authors / CoAuthors

Radke, L.C.

Abstract

Geoscience Australia marine reconnaissance survey TAN0713 to the Lord Howe Rise offshore eastern Australia was completed as part of the Federal Government's Offshore Energy Security Program between 7 October and 22 November 2007 using the New Zealand Government's research vessel Tangaroa. The survey was designed to sample key, deep-sea environments on the east Australian margin (a relatively poorly-studied shelf region in terms of sedimentology and benthic habitats) to better define the Capel and Faust basins, which are two major sedimentary basins beneath the Lord Howe Rise. Samples recovered on the survey contribute to a better understanding of the geology of the basins and assist with an appraisal of their petroleum potential. They also add to the inventory of baseline data on deep-sea sediments in Australia. The principal scientific objectives of the survey were to: (1) characterise the physical properties of the seabed associated with the Capel and Faust basins and Gifford Guyot; (2) investigate the geological history of the Capel and Faust basins from a geophysical and geological perspective; and (3) characterise the abiotic and biotic relationships on an offshore submerged plateau, a seamount, and locations where fluid escape features were evident. This dataset comprises organic carbon and nitrogen concentrations and isotopes in the upper 2 cm of seabed sediments. Some relevant publications which pertain to these datasets include: 1. Heap, A.D., Hughes, M., Anderson, T., Nichol, S., Hashimoto, T., Daniell, J., Przeslawski, R., Payne, D., Radke, L., and Shipboard Party, (2009). Seabed Environments and Subsurface Geology of the Capel and Faust basins and Gifford Guyot, Eastern Australia - post survey report. Geoscience Australia, Record 2009/22, 166pp. 2. Radke, L.C. Heap, A.D., Douglas, G., Nichol, S., Trafford, J., Li, J., and Przeslawski, R. 2011. A geochemical characterization of deep-sea floor sediments of the northern Lord Howe Rise. Deep Sea Research II 58: 909-921

Product Type

dataset

eCat Id

82536

Contact for the resource

Digital Object Identifier

http://dx.doi.org/10.4225/25/54B8660EED00C

Keywords

• Marine Data

( Theme )

• marine survey

( Theme )

• Continental Shelf

( Theme )

• seabed

( Theme )

• geochemistry

( Theme )

• marine

• AU-QLD

Australian and New Zealand Standard Research Classification (ANZSRC)

• Marine Geoscience

• Published_External

Publication Date

2014-01-01T00:00:00

Creation Date

Security Constraints

Australian Government Security ClassificationSystem    

Classification - unclassified

Legal Constraints

Creative Commons Attribution 4.0 International Licence    

Access - license

Use - license

Status

Purpose

Maintenance Information

asNeeded

Topic Category

oceans

Series Information

Lineage

Bottom sediments were collected using either a box core, benthic sled or Van Veen Grab. Surface sediments (~0-2 cm) within grabs were spooned into falcon vials and the porewaters were removed by centrifugation. The samples were then frozen for transport to the laboratories at Geoscience Australia where measurements were made for total nitrogen (TN), 15N, TOC and 13C. Decarbonated sediment samples were weighed into tin foil cups and placed in an auto-sampler alongside a series of blanks and standards (ANU Sucrose, TO2 and caffeine for C and IAEA N1 and IAEA N2 and caffeine for N). A Thermo Finnigan Elemental Analyser (Flash EA, Series 1112) was used to pyrolyse the samples (after decarbonisation) into N2 and CO2 which were led into a Finnigan Mat 252 Mass Spectrometer interfaced to a Thermo Finnigan Conflo III. ISODAT 2.0 software was used for data acquisition. Isotopic measurements were made as 15N for N2 (vs atmospheric nitrogen) and 13C for CO2 (vs VPDB). Samples were corrected for the apparent offsets of reference materials (as measured against the working gas) from their expected value on an international scale. The average standard deviations on the replicate analyses were: 0.001 (TN), 0.04 (15N), 0.1 (TOC) and 0.2 (13C). Thanks to the crew of the RV Solander for help with sample collection.

Parent Information

Extents

[-27.3448, -26.066, 159.41532, 161.77743]

Reference System

Spatial Resolution

Service Information

Associations

Downloads and Links

File download  

Source Information

Source data not available.