断层崩积楔光释光测年适用性研究

OSL dating of fault collapse wedge

为了探讨断层崩积楔光释光测年的可行性,我们对山西忻定盆地两个探槽(西田探槽和南峪口探槽)的样品进行光释光测年分析,研究得出:对于年轻的样品采用中颗粒(63~90μm)单片再生法(SAR)定年,利用等效剂量分布直方图和累积频率图来判断其晒退情况,选择晒退较好的样品获得崩积楔的年龄;对于较老的样品采用细颗粒(4~11μm)简单多片再生法(SMAR),通过密集采样和系统数据综合分析而获得崩积楔的年龄。

In order to investigate the applicability of OSL dating for samples from fault collapse wedge,optical stimulated luminescence(OSL)method is used to date the samples collected from Nanyukou and Xitian trench in Xinding Basin.The results show that middle-grain(63—90μm)single-aliquot regenerative-dose(SAR)protocol can be used to date young samples.The equivalent dose distribution and cumulation frequency of samples are applied to detect the degree of OSL signal bleaching.The formation age of fault collapse wedge can be derived from the samples bleached well.Fine grain(4—11μm)quartz Sensitivitycorrected multiple aliquot Regeneractive-dose(SMAR)protocol can be used to date old samples.The formation ages of fault collapse wedge can be got by analyzing intensive samples systematically and synthetically.