However, in many depositional environments even the OSL signal may not be completely reset at deposition.
In the last decade ALRL has pioneered the measurement of single mineral grains as a method for identifying those grains which were reset, providing methods for dating such complex sediments.
Poor bleaching is a significant problem for Optically Stimulated Luminescence (OSL) dating of glacial sediments.
Five young glacial samples (including two modern analogues) from different depositional settings were collected beyond the Yingpu Glacier in the eastern Qinghai-Tibetan Plateau. The luminescence characteristics and dating results showed that the large aliquot quartz Blue Stimulated Luminescence (BSL) is more applicable than polymineral infrared stimulated luminescence (IRSL) method.
Many of the imaginative theories for the extinction of the dinosaurs will also be presented.
Within the uniformitarian paradigm, the meteorite impact theory, once considered ‘outrageous’, now is the dominant theory.
Occasional monospecific bone-beds and the rarity of fossils of very young dinosaurs suggest a catastrophic death and burial.
The billions of dinosaur tracks recently discovered provide testimony to unusual, stressful conditions.
Numerical techniques are best, but datable materials are often lacking, and in these cases age estimation must be made using relative-dating or correlation techniques.
Relative-dating techniques are nearly always applicable but are not precise and require calibration.
Correlation techniques are locally useful and depend on recognition of an event whose age is known, such as a volcanic eruption or a paleomagnetic reversal.
Small aliquot quartz BSL results showed poor luminescence properties due to low luminescence sensitivity of quartz in this area.
The dating results also indicated that glaciofluvial samples deposited close to ice margin (~40 m and ~700 m) and supraglacial debris dominated lateral moraine samples are relatively well-bleached, whereas samples from ground moraine and low terminal moraine were poorly bleached, probably due to containing subglacial and englacial debris.