Coring Analyses of Cores from Near Shore Sites in the Vestfold Hills

The sedimentological, chemical and isotopic characteristics of sediment cores from three slightly saline to hypersaline lakes (Highway, Ace and Organic Lakes) and two marine inlets (Ellis Fjord and Taynaya Bay) in the Vestfold Hills, Antarctica have been examined.

Sections of the cores deposited in marine environments are characterised by uniform, regularly laminated, fine grained, organic-rich sediments, with uniform organic delta 13C values (-18.0 to 19.4 ppt vs. PDB) and sulfur contents. In contrast, sediments deposited in lacustrine environments are extremely heterogeneous, varying from finely laminated mat-like sequences to poorly sorted clastic-rich sediments. Authigenic monohydrocalcite and aragonite occur in some lake sediments.

The delta 13C values of organic matter in the lacustrine sediments exhibit an extremely wide range (-10.5 to -25.3 ppt) that can be related to variations in physico-chemical conditions in the lake waters. Strongly negative organic-delta 13C values coupledwith high sulfur contents are indicative of an anoxic zone in the overlying lake waters, whereas less negative organic-delta 13C values coupled with low sulfur contents are indicative of well-mixed oxic conditions. Particularly high organic-delta 13C values result during high levels of microbial activity in the lakes, due to high rates of photosynthetic CO2 fixation. The large shifts in organic-delta 13C are not necessarily accompanied by any change in macroscopic sedimentological characteristics, illustrating the utility if isotopic investigations in these environments. The delta 13C composition of authigenic carbonate in hypersaline Organic Lake sediments provides a record of changes in palaeoproductivity, while the delta 18O of the carbonate provides information on rates of meltwater input and evaporation in the lake. 14C-dating suggests that Highway Lake was isolated from the sea by isostatic uplift at least 4600 years before present (BP) whereas Organic Lake was isolated at approximately 2700 years BP. Apparent emergence rates calculated from the 14C ages range from 1.0 to 2.1 mm per year.

The 'reservoir effect' in the lacustrine and marine environments is variable, but probably does not exceed ~ 1000 years in any of the lakes examined.

Identification info

Alternate title: Coring Analyses of Cores from Near Shore Sites in the Vestfold

Date (Publication): 2003-03-05

Edition: 1

Citation identifier

Dataset DOI

Title: Information and documentation - Digital object identifier system

Date (Publication): 2012-04-23

Citation identifier: ISO 26324:2012

Citation identifier: doi:10.4225/15/57E373C58D19E

Originator

Burton, H.

Publisher

Australian Antarctic Data Centre

Principal investigator

BURTON, HARRY

Australian Antarctic Division

203 Channel Highway

Kingston

Tasmania

7050

Australia

Collaborator

BURTON, HARRY

Australian Antarctic Division

203 Channel Highway

Kingston

Tasmania

7050

Australia

Name: CAASM Metadata

Website: https://data.aad.gov.au/metadata/records/ASAC_310

Status: Completed

Custodian

AU/AADC > Australian Antarctic Data Centre, Australia - AADC, DATA OFFICER (DATA CENTER CONTACT)

Australian Antarctic Division

203 Channel Highway

Kingston

Tasmania

7050

Australia

+61 3 6232 3244

+61 3 6232 3351 (facsimile)

Topic category

Climatology, meteorology, atmosphere
Environment
Geoscientific information
Inland waters
Oceans

Extent

Description: Temporal Coverage

Temporal extent

TimePeriod: 1978-09-01 1987-12-31

Extent

Description: Vertical Extent - Depth

Vertical element

Minimum value: 7.5

Maximum value: 117

Identifier: urn:x-ogc:def:cs:EPSG:6498

Name: Vertical CS. Axis: depth (D). Orientation: down. UoM: m.

Identifier: urn:x-ogc:def:axis:EPSG:113

Name: depth

Title: Sedimentological and stable-isotope evolution of lakes in the Vestfold Hills, Antarctica.

Date (Publication): 1991

Citation identifier: 84