The volcanic rock age and the age of the qiangtang formation determined the wudaoliang group between 20 - 5ma , discovering a flood of spore and pollen with ostracods fossils ( regard eucypris as principle ) , which are miocene epoches typical numerator , therefore wudaoliang group accumulate in miocene epoch is doubtless ; 9 - 2ma are the age of the suonahu formation based on the data of the esr , which were characteristic of later period in miocene epoch - pliocene epoch , spore and pollen with fossil all were miocene epoch period 由火山岩和覆于其上的羌塘组的年龄限定五道梁群的沉积时间为20 - 5ma ，五道梁群中发现大量的孢粉和介形虫化石(以eucypris为主) ，分析认为它们都是中新世时期的典型分子，因此五道梁群的沉积时间为中新世是无疑的；唢呐湖组的esr测年数据范围为9 - 2ma ，代表中新世晚期?上新世时期，孢粉和化石都具有中新世时期的特征。
