Data

Age vs Depth profile of core GC12, collected from the Capricorn Channel off the Eastern Australian Coast

Australian Ocean Data Network
Bostock, Helen ; Opdyke, Bradley, Dr
Viewed: [[ro.stat.viewed]] Cited: [[ro.stat.cited]] Accessed: [[ro.stat.accessed]]
ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rfr_id=info%3Asid%2FANDS&rft_id=https://catalogue.aodn.org.au:443/geonetwork/srv/api/records/8a1e5f30-2506-11dc-aba4-00188b4c0af8&rft.title=Age vs Depth profile of core GC12, collected from the Capricorn Channel off the Eastern Australian Coast&rft.identifier=https://catalogue.aodn.org.au:443/geonetwork/srv/api/records/8a1e5f30-2506-11dc-aba4-00188b4c0af8&rft.description=A gravity core (GC12) was collected from a depth of 990.5 mbsl within the Capricorn Channel, southern Great Barrier Reef (GBR). Isotopic values for 18-O and 13-C were obtained from Globigerinoides ruber and correlated with the SPECMAP age-model. Radiocarbon dating of Globigerinoides sacculifer was also undertaken at nine sample depths, and then corrected and correlated with the curve. This yielded an age vs. depth profile from which it was possible to determine approximate sedimentation rates. From the age-model we see the evidence of MIS 1 through to 5a with sedimentation rates ranging from 2 cm/kyr to 20 cm/kyr, with an average of 10cm/kyr. This is a high sedimentation rate for a sedimentary basin, however the core is situated on the increased slope of the Capricorn Channel, therefore sediments scoured off the shallow gradient slope above may feasibly be focused at this depth on the slope. The sedimentation rate exhibits a unorthodox pattern, with a very high rate (25 cm/kyr) during the middle of MIS 3.Maintenance and Update Frequency: notPlannedStatement: Age-model constructed by correlating 18-O data with the SPECMAP model of Martinson et al.(1987). Samples were dried in the oven before being re-soaked in distilled water. Samples then wet sieved through a series of four mesh sizes before the size fractions were transferred to drying trays. After drying foraminifera were picked from the large size fractions of >300 µm and >400µm. 10-15 white Gs. ruber were hand picked to give a total sample weight of 180-220µg for isotope analysis. The samples were washed in methanol and ultrasonicated for 30 secs to remove surface and internal particles. Samples were analysed at the Research School of Earth Science, Australian National University, using an automated individual carbonate reaction (Kiel) device coupled with a Finnigan MAT-251 mass spectrometer. Radiocarbon dating was undertaken on ~300 individuals of G. sacculifer from >300µm size fraction. Samples were rinsed, ultrasonically cleaned, and then dried. Samples were then dissolved in 103% orthophosphoric acid and the CO2 collected under vacuum. The CO2 was converted to graphite by reacting with hydrogen over an iron catalyst at 600oC. The graphite, once formed, is transferred to small cathodes and run on the AMS.Statement: Age estimates are provided for 5cm, 10cm, 15cm, 20cm and then every 10cm down the core to a depth of 510cm. These estimates were made primarily by correlating 18-O values with the SPECMAP age-model. Values of 18-O have a very small analytical error. Radiocarbon dating was undertaken on samples at 20cm, 30cm, 80cm, 90cm, 150cm, 190cm, 250cm, 300cm and 350cm depths. These values are provided, before being corrected and calibrated with the age curve. Parameters: Depth through core (cm), carbon-14 age (yr BP), error (yr), calibrated age (yr BP), sedimentation rate (cm/kyr).&rft.creator=Bostock, Helen &rft.creator=Opdyke, Bradley, Dr &rft.date=2007&rft.coverage=153.83198,-23.57259 153.83270,-23.57258 153.83264,-23.57319 153.83192,-23.57316 153.83198,-23.57259&rft.coverage=westlimit=151.5; southlimit=-24.5; eastlimit=153; northlimit=-23&rft.coverage=westlimit=151.5; southlimit=-24.5; eastlimit=153; northlimit=-23&rft.coverage=uplimit=990.5; downlimit=990.5&rft.coverage=uplimit=990.5; downlimit=990.5&rft_rights=Creative Commons Attribution 2.5 Australia License http://creativecommons.org/licenses/by/2.5/au/&rft_rights=The citation in a list of references is: citation author name/s (year metadata published), metadata title. Citation author organisation/s. File identifier and Data accessed at (add http link).&rft_subject=environment&rft_subject=SEDIMENTATION&rft_subject=EARTH SCIENCE&rft_subject=OCEANS&rft_subject=MARINE SEDIMENTS&rft_subject=ISOTOPES&rft_subject=PALEOCLIMATE&rft_subject=OCEAN/LAKE RECORDS&rft_subject=51200000&rft_subject=Foraminiferida&rft_subject=Foraminiferans&rft_subject=Foraminifera&rft_subject=core_depth&rft_subject=conventional_C14_age&rft_subject=error&rft_subject=calibrated_age&rft_subject=sedimentation_rate&rft.type=dataset&rft.language=English Access the data
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The citation in a list of references is: citation author name/s (year metadata published), metadata title. Citation author organisation/s. File identifier and Data accessed at (add http link).

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A gravity core (GC12) was collected from a depth of 990.5 mbsl within the Capricorn Channel, southern Great Barrier Reef (GBR). Isotopic values for 18-O and 13-C were obtained from Globigerinoides ruber and correlated with the SPECMAP age-model. Radiocarbon dating of Globigerinoides sacculifer was also undertaken at nine sample depths, and then corrected and correlated with the curve. This yielded an age vs. depth profile from which it was possible to determine approximate sedimentation rates. From the age-model we see the evidence of MIS 1 through to 5a with sedimentation rates ranging from 2 cm/kyr to 20 cm/kyr, with an average of 10cm/kyr. This is a high sedimentation rate for a sedimentary basin, however the core is situated on the increased slope of the Capricorn Channel, therefore sediments scoured off the shallow gradient slope above may feasibly be focused at this depth on the slope. The sedimentation rate exhibits a unorthodox pattern, with a very high rate (25 cm/kyr) during the middle of MIS 3.

Lineage

Maintenance and Update Frequency: notPlanned
Statement: Age-model constructed by correlating 18-O data with the SPECMAP model of Martinson et al.(1987). Samples were dried in the oven before being re-soaked in distilled water. Samples then wet sieved through a series of four mesh sizes before the size fractions were transferred to drying trays. After drying foraminifera were picked from the large size fractions of >300 µm and >400µm. 10-15 white Gs. ruber were hand picked to give a total sample weight of 180-220µg for isotope analysis. The samples were washed in methanol and ultrasonicated for 30 secs to remove surface and internal particles. Samples were analysed at the Research School of Earth Science, Australian National University, using an automated individual carbonate reaction (Kiel) device coupled with a Finnigan MAT-251 mass spectrometer. Radiocarbon dating was undertaken on ~300 individuals of G. sacculifer from >300µm size fraction. Samples were rinsed, ultrasonically cleaned, and then dried. Samples were then dissolved in 103% orthophosphoric acid and the CO2 collected under vacuum. The CO2 was converted to graphite by reacting with hydrogen over an iron catalyst at 600oC. The graphite, once formed, is transferred to small cathodes and run on the AMS.
Statement: Age estimates are provided for 5cm, 10cm, 15cm, 20cm and then every 10cm down the core to a depth of 510cm. These estimates were made primarily by correlating 18-O values with the SPECMAP age-model. Values of 18-O have a very small analytical error. Radiocarbon dating was undertaken on samples at 20cm, 30cm, 80cm, 90cm, 150cm, 190cm, 250cm, 300cm and 350cm depths. These values are provided, before being corrected and calibrated with the age curve. Parameters: Depth through core (cm), carbon-14 age (yr BP), error (yr), calibrated age (yr BP), sedimentation rate (cm/kyr).

Notes

Credit
Funded by The Australian Research Council (ARC)
Credit
Funded by The Australian National University (ANU) Faculties Research Grant Scheme
Purpose
To determine the sedimentological variations with sea-level over the last glacial/ interglacial cycle in the Capricorn Channel. Very little previous work has been undertaken within this area.

Issued: 28 06 2007

Data time period: 1997 to 1997

This dataset is part of a larger collection

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153.83198,-23.57259 153.8327,-23.57258 153.83264,-23.57319 153.83192,-23.57316 153.83198,-23.57259

153.83231,-23.572885

153,-23 153,-24.5 151.5,-24.5 151.5,-23 153,-23

152.25,-23.75

text: westlimit=151.5; southlimit=-24.5; eastlimit=153; northlimit=-23

text: uplimit=990.5; downlimit=990.5

Subjects
51200000 | EARTH SCIENCE | Foraminifera | Foraminiferans | Foraminiferida | Isotopes | MARINE SEDIMENTS | OCEAN/LAKE RECORDS | OCEANS | PALEOCLIMATE | Sedimentation | calibrated_age | conventional_C14_age | core_depth | environment | error | sedimentation_rate |

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Other Information
(ANU_Bostock_GC12_2_data.xls)

url : https://catalogue.aodn.org.au:443/geonetwork/srv/api/records/8a1e5f30-2506-11dc-aba4-00188b4c0af8/attachments/ANU_Bostock_GC12_2_data.xls

Core data - Capricorn Channel (aodn: bluenet_datasets_capricorn_channel)

url : http://geoserver-123.aodn.org.au/geoserver/wms

global : 442c6f30-2501-11dc-aba4-00188b4c0af8

Identifiers
  • global : 8a1e5f30-2506-11dc-aba4-00188b4c0af8