激光断代

Optical dating

激光断代是一项直接测定沉积物年的新技术,尚处在实验阶段,和TL测定沉积物年代一样,光断代置零机制也是光暴露。两者区别在于TL是用加热测定古剂量,而光断代是用单色光照射矿物洲其古剂量,例如通常用由(气业)离子激光器发射的514nm的绿色波长。在光断代中,光仅仅用于测量俘获电子数目中的光敏陷阱积累的电子,那些电子假定在沉积物沉积过程中已放阳光排空。这样,利用阳光晒退就可以基本上解决沉积物断代中的置零问题。

Optical dating is a new, and as yet at experimental stage, technique for the direct dating of sediments. As in the TL dating, the zeroing mechanism in optical dating is exposure to light. While in TL dating the paleodose is measured by heating the minerals, in optical dating this is done by exposing the minerals to monochromatic light, e. g. the 514nm green wavelength emitted by an argon ion laser. In optical dating, the light is used to measure the trapped electron population, an which only the electrons accumulated in light-sensitive elec-tron traps and assumed to be completely emptied by sunlight during the process of deposition, are measured. Thus, the zeroing problem can be basically solved by sunlight bleaching in the sediment dating.