Â鶹Éçmadou

Synopsis

Speleothems (including stalagmites, stalactites are flowstones) are secondary cave deposits. As they grow, they include a range of chemical and physical tracers. These data can be used as proxies to interpret past environments. Understanding past climates is essential to improving our understanding of present and future climates. Southwest Western Australia (SWWA) is projected to get both warmer and drier as climate change progresses. Indeed, SWWA is already experiencing a drying trend. Speleothem archives have demonstrated that this drying trend is accompanied by reduced groundwater recharge, unmatched in the past 800 years (Priestley et al., 2023).

Stalagmite LAB-S1 was sampled from Labyrinth Cave, in the Capes region of SWWA in 2009. The section is shown here. The sample has two main growth phases. One, during the early Holocene (grey colour; dates suggest it grew for ~1500 years from 12.5 ka BP to 11 ka BP), and another from ~1937 until it was removed (cream coloured). Stalagmites in SWWA tend to be annually laminated, a result of the high seasonality in rainfall due to the Mediterranean climate, and these laminae can be counted to provide highly precise chronologies for palaeoclimate research. The early Holocene (11.7 – 8.2 ka) represents a time of rapid climatic change, globally, as the last glaciation terminated and climate worldwide rapidly approached modern conditions. Comparisons between the Holocene stalagmite record with the modern stalagmite record will enable us to contextualise the modern rate of change in the climate of SWWA.

This project will make use of a complete dataset of trace elements (via LA-ICP-MS and Synchrotron XFM) and stable O and C isotopes (δ¹⁸O and δ¹³C) and U/Th dates.

Aims

To construct a record of past climate for the early Holocene in SWWA using speleothem geochemistry.

Student benefits

You will learn about palaeoclimate science and speleothem science. You will be supported to expand your data management and data analysis toolsets (including coding and timeseries analyses). You will gain experience processing and analysing geochemical data. You will be supported by a supervisory team based at both Â鶹Éçmadou Sydney and at the Max Planck Institute for Chemistry, Germany. Your mentorship will include regular meetings and conversations about your project, and you will be supported to develop a skillset tailored towards where you would like to see your future career head. Students with some experience in geochemistry are especially invited to apply, but this is not a prerequisite.

Supervisor: Micheline Campbell (MPIC; Â鶹Éçmadou), Andy Baker (Â鶹Éçmadou), and Pauline Treble (ANSTO; Â鶹Éçmadou)