Optical dating techniques
However, loess sequences outside the Loess Plateau have received much less attention and a lack of accurate chronology poses major uncertainty in the correlation of paleoclimate events over wide areas.
Optically stimulated luminescence (OSL) dating has been widely applied to the Late Pleistocene loess deposits within the Loess Plateau during the last decade and most of the studies have used quartz extracted from the loess samples.
Recently, underestimation of OSL ages has been reported for quartz when samples with expected age older than about 70 ka are dated.
Infrared stimulated luminescence (IRSL) signal of feldspars saturates at much higher dose than quartz and therefore holds a potential for dating loess deposited before the Late Pleistocene.
However, by itself a fossil has little meaning unless it is placed within some context.Plaggen agriculture was the dominant land use system in the Pleistocene cover sand area of Northwest Europe before the introduction of chemical fertilisers.In today's landscape Fimic horizons and driftsand deposits are characteristic survivors of plaggen agriculture.Experiments were designed to investigate the the accuracy and limitations of the dating protocols for quartz and feldspars.Significant difference in luminescence behavior has been observed for samples from different regions.
Search for optical dating techniques:
Loess, which is widely distributed across many parts of China, provides valuable records of changes in wind pattern and aridity of East Asia throughout the Quaternary.