Natasha Lelieveld

Contact

Email: Natahsa.Lelieveld@vuw.ac.nz
Office: CO421

Qualifications

BSc VUW (2019)
MSc Candidate in Antarctic paleoclimate

Master thesis

Title

Paleoenvironment and climates of the Ross Sea during the early and middle Miocene from sediment drill core archives.

Supervisors

• A/Prof Rob McKay
• Dr Bella Duncan

Project objectives and description

The aims of the project is to conduct analysis on cores DSDP 273 and 272 to develop a stratigraphic record prior to (>17 Ma) and during the MCO (~17-14.6 Ma), and stratigraphically correlate to high-resolution record of the early MCO from IODP core 1521. There are two main parts to this study: the first is to reconstruct paleoenvironments and ice sheet proximity in the outer Ross Sea continental shelf using sedimentary and geochemical analysis of the early- to middle Miocene intervals of cores DSDP 272 and 273. The second aim is to reconstruct a low- to moderate resolution of past sea surface and terrestrial temperature trends and shifts prior to, during and following the MCO in the Ross Sea.

IODP U1521 core has produced a high-resolution continuous record from a diatom-rich mudstone deposited during the early Miocene Climate Optimum (MCO) (17-15 Ma), but the top of this unit consists of a glacial erosion surface that has led to a hiatus in U1521 between 15.8 and 14.6 Ma, and therefore this part of the MCO is missing at that site. U1521 also contains glacimarine diamictites prior to 17 Ma complicating the application of paleoenvironment proxies used to reconstruct past temperatures. A new seismic stratigraphic correlation and refined age models of DSDP Sites 272 and 273 suggest the potential that continuous fine grained lithofacies exist at these sites for times prior to 17 Ma at DSDP Site 272, and after the MCO - between 15.8 and ~14.6 at DSDP Site 273 and between 14.6 and 13 Ma at DSDP Site 272. Combined with results from U1521 obtained by the IODP Expedition 374 Science Team, this may allow for a continuous stratigraphic records of prior to, during and following the MCO in the Central Ross Sea.