Introduction to the special issue on application of luminescence dating in geomorphology

Luminescence dating is unique amongst geochronological methods because it directly dates the time of deposition of sediments using some of the commonest detrital minerals on the earth's surface: quartz and feldspar (Duller, 2004). There has been considerable development in luminescence dating methods over the last 5–10 years, and it is now a reliable and widely used chronological tool covering the period between a few decades and about 100,000 years (Murray and Olley, 2002). This has led to a variety of applications in geomorphology, especially where radiometric dating methods were not applicable due to the age range or the lack of suitable materials. The papers in this special issue cover almost the entire range possible with luminescence, from a few decades to almost 100 ka, and illustrate the wide range of depositional environments in which luminescence can be applied. The maturity of the technique means that it is now possible to identify from the luminescence characteristics alone, those samples where luminescence is more complex, and those where the technique is more straightforward. This special issue contains two review and five original papers. Madsen and Murray provide a review of applications using young (<1000 years) coastal and aeolian sediments and illustrate how well optically stimulated luminescence (OSL) dating works for very young sediments complementing techniques such as 14C, 210Pb and 137Cs. Aeolian and shallow marine sediments are ideally suited to luminescence dating since transport by wind or in coastal zone provides ample opportunity for grains to be exposed to daylight, thus resetting the luminescence ‘clock’ to zero. Fuchs and Lang consider the possibilities and challenges for luminescence dating when applied to colluvial deposits. Colluvium is often exposed to limited amounts of light prior to deposition, and the authors give guidelines for sampling and analytical techniques to deal with this issue. The five original papers include studies dealing with aeolian, marine, fluvial and periglacial sediments. Derese et al. date samples from a dune sand complex from northeast Belgium. Prior to this study, the site had been regarded as a type locality for Late Glacial dune sands containing both Bølling and Allerød peats; however, the results presented here show that all the sands were deposited during the Allerød requiring a reinterpretation of the site. Madsen et al. applies OSL dating to hurricane deposits from Massachusetts, USA. Previous studies have relied upon 14C dating, but over the last few hundred years the calibration curve is complex, resulting in multiple possible dates. This study demonstrates that luminescence can provide ages that are consistent with existing chronological controls and which can be used to extend the existing hurricane record, thus improving estimates of the past hurricane activity. Zacharias et al. date deltaic sediments from eastern Crete, Greece to investigate the relationship between human occupation of the area and Holocene environmental changes. Zhang et al. date fluvial terrace sediments of the Yellow River, China, and discuss the evolution of the terraces for the last ~ 90 ka. Hülle et al. investigate periglacial sediments from Germany. Their material is very challenging for OSL dating as the environmental dose rate is heterogeneous and the OSL from their quartz is dim; they make suggestions of how to deal with such periglacial sediments. We hope that this special issue will attract interest from geomorphologists and others, and that it will contribute to the development and use of luminescence in geomorphological applications.