Challenges in luminescence dating applications of quartz
Projektnummer: 50022024 ARC-XXIII
- Dr Richard Bailey (University of Oxford)
- Dr Morteza Fattahi (University of Oxford)
- Christoph Schmidt (Universität Köln)
Challenges in luminescence dating applications of quartz - a DAAD exchange project.
Luminescence dating methods using quartz may suffer from i) incomplete optical resetting (bleaching) of the latent signal at deposition, ii) limited saturation dose and,thus, limited time range using UV-A or blue emissions. The project objectives first consists in exploring and separating OSL emissions from quartz of different sensitivity to light and to isolate components suited for specific dating applications with the Linear Modulation technique. Rapid environmental change with or without human impact will be dated more precisely and more reliably using this sophisticated technique. Secondly it is tried to extend the upper dating limit by using orange-red TL emissions (RTL) from quartz extracted from heated samples (e.g., crustal xenoliths from volcanic eruptions) and from sediments which are too old for conventional OSL dating.
Both approaches require fundamental research into the luminescence characteristics of (dose-saturated) quartz crystals from different geological origin (granitic, hydrothermal, sedimentary).
Objectives in order
1. Sampling and refining pure quartz from different geological and petrographic environments and from a well-studied last glacial loess section (Nussloch)
2. Investigating basic luminescence characteristics from different quartz of different origin, with focus on OSL components (LM-OSL) and red TL emissions (RTL)
3. Testing improved techniques (LM-OSL) to recognize incomplete or inhomogeneous signal resetting at deposition and to precisely determine the true burial dose.
4. Extending the upper limit of luminescence dating through use of RTL emissions from heated and from sedimentary quartz.
5. Improving and ensuring of dose rate calculations using different low-level methods including modeling of disequilibrium and spatial non-homogeneity if applicable.
6. Comparing dating results from loess with independent chronologies and other high resolution records of rapid climate change.