Equipment for luminescence preparation and measurement
A non-commercial laboratory facility that currently supports Macquarie staff and HDR students, higher degree research and undergraduate teaching, and external collaborations.
Luminescence dating
Luminescence dating is a trapped charge technique whereby electrons are ‘trapped’ in defects in minerals such as quartz and feldspar.
This trapped signal is light sensitive and builds up over time during a period of no light exposure (during deposition or burial) but when exposed to light (natural sunlight or artificial light in a laboratory) the signal is released from the traps in the form of light – called luminescence.
In this facility we aim to sample these minerals (found in all sediments) without exposing them to light so that we can stimulate the trapped signal, within controlled laboratory conditions, using:
- heat (thermoluminescence – TL)
- light (optically stimulated-luminescence – OSL).
The amount of light produced is directly proportional to the amount of electrons that have built up over time. This provides a radiometric ‘clock’ that can be used to establish the time since the mineral grains were last exposed to sunlight, which equates to the depositional age.
Research applications
As most sedimentary processes or events are based on the deposition of sediment, these depositional ages are critical to geomorphological research.
The age of sediment deposition is also crucial for the evidence found within the sediment such as pollen, fossils and artefacts. Therefore, the technique is relevant for paleoclimatology, archaeological and paleontological research.
The facility supports existing research programs investigating:
- climate change
- natural hazards
- coastal and river management
- human-environment interactions.
Laboratory equipment
The facility houses state-of-the-art luminescence preparation and measuring equipment within two specially designed subdued red-light laboratories:
- a fully equipped wet room preparation area with a core and tube opening station, HF fume hoods, wet and dry sieving and mineral separation stations, and a ball mill
- a dry instrument room contains two ‘Riso’ automated luminescence readers (one with single-grain capabilities and the other with a red TL setup), a low-level beta GM multicounter and two Daybreak 583 thick-source alpha counters.
The entire facility is an AQIS approved place for the processing of quarantined samples and houses a specially designed AQIS storage room.
Funding
The facility is supported by:
- internal RIBG and MQSIS funding
- joint ARC LIEF funding in collaboration with UTS, UNSW and UNE.