Full description
Core GC04, was collected from the southeastern side of the New Caledonian Basin (22.99965 S, 166.150716 E). Carbonate percent in the curve has an average value of ~79% and varies between 51.4% and 88.8%. Carbonate pecent does show small variations in scale and repeating patterns, however data tends to stay between 70-80%. It is interesting to note that the carbonate percent minimum of 51.4% occurs at the beginning of isotope stage 4 (~73Ka BP). This anomaly is relatively simultaneous to a decrease in 18O and slight increase in sedimentation rate. Significant non-carbonate sediments include glass shards, sub-rounded quartz, radiolarians, sponge spicules, manganese nodules and 'red opaque' material. Trends of glass shard and quartz percentages can be seen in the results. Radiolaria and sponge spicles tend not to show any definite trend, however both tend to increase subsequent to a broader non-carbonate sedimentation increase.Lineage
Maintenance and Update Frequency: notPlanned
Statement: Percentages of carbonate and non-carbonate material are provided for every 2cm of the core down to a depth of 140cm. It is thought that the 'red opaque' minerals in the non-carbonate fraction are likely to be the bi-product of treatment in the laboratory when diluted (3%) H2O2 was added to the samples to dissociate the clay aggregates.
CARBONATE - 1g dried sample ground down to ~63 microns with a pestle & mortar. Sample weighed before being placed into a clean beaker containing a magnetic stirrer with 125mL of distilled water, and put on a hotplate at ~80oC for min. of 20mins, to dissolve all CaCO3. 20mL of ~0.5M NaOH added and solution titrated with ~1M HCl until reaches pH 7. A standard is run every 5-10 samples to ensure results not drifting.
NON-CARBONATE - Samples washed in diluted (3%) H2O2 to dissociate clay aggregates. 3% HCl and distilled water addred to 1g of sediment to dissolve all carbonate. Jars sealed and left for a minimum of 24hrs. Once all of carbonate was dissolved, sediment sieved through 60µm mesh, washed into an alcohol filled jar. Sediment stored in alcohol with the jar tightly fitted. Terrigenous content was determined by (a) counting the number of each of the main components if there was little sediment, or (b) by counting each main component in the viewer at x8 magnification and calculating the proportinate amount of sediment for the whole sample.
Parameters: Core depth (cm), time (ka BP), % carbonate material (%), % non-carbonate material (%), % glass-shards (%), % quartz (%), % radiolarians (%), % sponge spicules, % manganese nodules (%), % red opaque material (%), % other material (%).
Notes
CreditFunded by The Australian Research Council (ARC)
Credit
The Australian National University (ANU)
The Australian National University (ANU)
Purpose
To look at carbonate trends in bulk sediment in order to recognise whether there is any dominant pattern in carbonate over time for the New Caledonia Basin, southwest Pacific. Non-carbonate fraction analysis is looked at in order to explain any abnormal fluxes in the carbonate sediment.
To look at carbonate trends in bulk sediment in order to recognise whether there is any dominant pattern in carbonate over time for the New Caledonia Basin, southwest Pacific. Non-carbonate fraction analysis is looked at in order to explain any abnormal fluxes in the carbonate sediment.
Issued: 19 06 2007
Data time period: 2001 to 2001
text: westlimit=142; southlimit=-30; eastlimit=170; northlimit=-7
text: uplimit=2477; downlimit=2477
Subjects
Oceans | Marine Sediments | Carbonate Sediments |
amount_of_carbonate |
amount_of_non-carbonate |
core_depth |
environment |
time |
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Other Information
(ANU_Gretton_GC04_4_data.xls)
Core data - New Caledonian Basin (aodn:bluenet_datasets_new_caledonian_basin)
Identifiers
- global : 4c4c4df0-1e23-11dc-badd-00188b4c0af8
