Dr. Chris Mays - Honours Projects

Polar palaeoclimates during the warmest interval in Earth’s history: the mid-Cretaceous hothouse

Supervisor(s): Chris Mays and Jeffrey Stilwell.
Fields of study: Palaeoclimatology, stratigraphy, isotope geochemistry
Support offered: Laboratory, analytical, and thesis-preparation costs.
Funding organisations: National Geographic, Australian Nuclear Science and Technology Organisation.

The mid-Cretaceous thermal maximum was an interval of acute global warming, and is demarcated in the fossil record as a marine mass extinction. This interval is also renowned as one of critical tectonic and evolutionary change; the final break-up of the Gondwanan supercontinent was underway, in the midst of the most radical revolution in floral history: the diversification of the flowering plants.

This investigation will involve the geochemical analysis of fossil macroflora to provide a chemostratigraphic time-series across a crucial climatic interval in Earth’s history: the mid-Cretaceous Oceanic Anoxic Event (OAE2). The project will involve the extraction of large amounts of fossil-rich material to obtain this time-series and the correlation of these data to the stratigraphy of the Chatham Islands, Zealandia. This project will provide a key correlation point for Gondwanan chronostratigraphy. Furthermore, the findings of this study will form the basis of the most comprehensive mid-Cretaceous palaeoclimatic reconstruction of southern Gondwana during this interval of extreme climatic, tectonic and floristic evolution.

For further information contact: Chris Mays

The south polar fossil forests of the mid-Cretaceous

Supervisor(s): Chris Mays and Jeffrey Stilwell.
Fields of study: Palaeobiology, palaeoecology, palaeoclimatology
Support offered: Laboratory, analytical, and thesis-preparation costs.
Funding organisations: National Geographic.

The south polar forest biome of the mid-Cretaceous was a key dispersal corridor between eastern and western Gondwana for both animals and plants prior to supercontinental break-up. The constituents and evolution of these forests formed the basis of the modern floras of the Southern Hemisphere. However, the constituents of these forests are not well known, and many important ecological and biological questions remain about how these forests lived, indeed thrived, at a latitude that is characterised by months of continuous darkness and extensive ice sheets today.

This project will reconstruct these ancient polar forests by examining the fossil forests of mid-Cretaceous strata of the Chatham Islands, which represents the highest latitude mid-Cretaceous fossil locality of Gondwana. Three primary methods will be employed: 1) the first taxonomic treatment of fossil woods from this locality; 2) palynological analysis to address the ecological interactions between primary floral groups; 3) sedimentological analysis will be carried out on the several palaeosols with in situ tree trunks for forest density, structure and biomass estimates. As such, this project aims to be an integration of numerous lines of evidence to build a story of the forest-builders, their ecological counterparts and the environments they inhabited.

For further information contact: Chris Mays

Cretaceous-Paleogene Bioinclusions in Amber from the Otway and Gippsland basins, and their Palaeontologic Significance

Supervisor(s): Jeffrey Stilwell and Chris Mays
Fields of study:
Applied Palaeontology and Basin Studies
Support offered: All travel, field, analytical, and thesis-preparation costs
Collaborating Organisation: Australian Research Council and investigators from the Australian Museum and Royal Botanic Gardens (Melbourne)

Fossil bio-inclusions in resin can provide important information on ancient ecosystems and their interpreted palaeoenvironments, and depending on what taxa are recovered, there may also be pollen for palynological studies and the potential for a refined biostratigraphy. Amber is particularly significant as can preserve in perfect 3D a diverse array of organisms and associated remains from different habitats in and close to the amber-producing forests. Moreover, the discovery of amber bio-inclusions is of great importance as it can assist greatly in constructing the evolutionary history of lineages with otherwise poor fossil records. Australia has not been a major player in amber research, and currently, the only published accounts have been on probable Neogene-aged bioinclusions from Cape York. The discovery in May 2011 by JDS of fossiliferous Cretaceous amber from the Otway Basin has kick-started a concerted effort to learn more about Mesozoic and Paleogene terrestrial ecosystems of Australia. As there are undoubtedly many new discoveries to be made, southern Australia is a perfect case study for applied palaeontology analyses. Given the proximity of the Australian 3rd generation synchrotron and new techniques (e.g., phase contrast X-ray synchrotron microtomography) and imaging employing the ultramicroscope (XuM) being developed to study ancient amber, this is a significant investigation in palaeontology. The XuM is a SEM-hosted high resolution x-ray microscope with provides an internal view of the structure of the samples without cross-sectioning; providing 2D, stereo and full 3D tomographic imaging. The investigation will provide the student with state-of-the art analytical techniques and valuable experience in applied palaeontology methods.  Full costs of the project are borne by an Australian Research Council Discovery Grant to JDS.

For further information contact: Jeffrey Stilwell.