Diatom data from piston core PC06 and PC07 collected during voyage 1, 2017 of the RV Investigator

Full description

Diatom data from piston core PC06 and PC07 from research cruise IN2017_V01:

These data were generated by Amy Leventer ([email protected]), Department of Earth and Environmental Geosciences, Colgate University. All questions regarding the specifics of these data should be directed to Amy Leventer. These data are based on samples collected during research cruise IN2017_V01 of the RV Investigator, co-chief scientists, Leanne Armand and Phil O’Brien.

The IN2017-V01post-cruise report is available through open access via the e-document portal through the ANU library.

https://openresearch-repository.anu.edu.au/handle/1885/142525

The document DOI:
10.4225/13/5acea64c48693

The preferred citation is:

L.K. Armand, P.E. O’Brien and On-board Scientific Party. 2018. Interactions of the Totten Glacier with the Southern Ocean through multiple glacial cycles (IN2017-V01): Post-survey report, Research School of Earth Sciences, Australian National University: Canberra, http://dx.doi.org/10.4225/13/5acea64c48693

The piston cores presented in this entry supplement previous entries on other cores collected during expedition IN2017_V01. These two piston cores were sampled at ~10 cm intervals. In the lab at Colgate University, about 50-100 mg of sediment were weighed to the tenth of a mg and placed in 20 ml glass vials. Vials were placed on a warming tray set to 50 degrees C and 1 mL of hydrogen peroxide was added to each vial, followed by RH2O. This was done to oxidize organic material. Successive additions of 1 mL of hydrogen peroxide were done until samples had stopped reacting. RH2O was added as needed to avoid samples drying out. Slides then were made using the random settling and slide preparation methods in Warnock and Scherer (2014).
Diatoms were observed with an Olympus BH2 microscope using the 100x/1.30 oil immersion objective and 10x eyepieces, for a total magnification of 1000x. For each slide, if possible, at least 400 diatom valves were counted along non-overlapping transects. In samples with very few diatoms, all diatoms were counted for a total of 10 transects. Valves were only counted if >50% complete, and diatoms were identified to the species level when possible using identifications from Cremer et al. (2003), Cefarelli et al. (2010), and Al-Handal et al. (2022). Unidentified diatoms were placed in either the unidentified centric diatom or unidentified pennate diatom category.

Station_core Longitude (E) Latitude (S) water depth (m)

C019_PC06 120.143 E; -64.819 S; 3012m
C022_PC07 120.049 E; -65.131 S; 2611m

Al-Handal, A., Torstensson, A. and Wulff, A. (2022). Revisiting Potter Cove, King George Island, Antarctica, 12 years later: new observations of marine benthic diatoms. Botanica Marina, 65(2), 81-103. https://doi.org/10.1515/bot-2021-0066

Cefarelli, A., Ferrario, M., Almandoz, G., Atencio, A., Akselman, R. and Vernet, M. (2010). Diversity of the diatom genus Fragilariopsis in the Argentine Sea and Antarctic waters: Morphology, distribution and abundance. Polar Biology, 33. 10.1007/s00300-010-0794-z.

Cremer, H., Roberts, D., McMinn, A., Gore, D. and Melles, M. (2003). The Holocene Diatom Flora of Marine Bays in the Windmill Islands, East Antarctica. Botanica Marina, 46(1), 82-106. https://doi.org/10.1515/BOT.2003.010

Warnock, J. and Scherer, R. (2015). A revised method for determining the absolute abundance of diatoms. Journal of Paleolimnology, 53, 157-163. 10.1007/s10933-014-9808-0.

Lineage

Progress Code: completed

Statement: A dataset version with minor corrections was provided on 2025-06-04.

Notes

Purpose
The diatom data were collected for 2 primary purposes. (1) Development of core chronology, based on the alteration of high versus low diatom abundance as indicative of interglacial versus glacial periods, respectively and the use of key biostratigraphic indicators, such as the last occurrence of Hemidiscus karstenii as marking the boundary between Marine Isotope Stage 7 / Marine Isotope State 6. (2) Diatom assemblage data used for palaeoceanographic reconstruction.