As there are less such materials in loess as fossil , plants , slag , etc , which could be used for dating , luminescence dating , especially optically stimulated luminescence dating , was extensively applied to aeolian deposits , for its dating materials were minerals , such as quartz and feldspar 由于黄土中所含的化石、木质、炭屑等适于其它方法测年的物质很少，同时，全新世黄土受年轻有机碳和无机碳的影响较大，致使全新世黄土类沉积物的测年迄今仍缺少理想方法。
Prehistoric cataclysms and their impacts on human paleo - culture have been a focus of the scientists in the world . some ancient trees relatively undamaged back , roots and branches were unearthed from paleochannel in the peking university campus . the burying position , the characteristics and the age of the trees indicate that the flowage of ancient yongding river resulted in the event at about 5000a b p . the trees , together with the neolithic culture relic unearthed at the same time , show that the disastrous floods definitely occurred at about 5000a b p in peking area 史前时期的大洪水及其对人类古代文明的影响一直是中外学者共同关心的问题。北京大学校园内出土的埋藏古树，其埋藏特征和测年数据表明它们是5000a b p前后古永定河洪水泛滥的产物，与古树同时出土的新石器时期文化遗物，提供了洪水给古代人类带来重大灾难的信息。
In order to elaborate the app licability of osl to loess , especially single aliquot regenerative protocol ( sar ) , involving stimulation of the same disc with an infra - red laser diode followed by blue leds to polymineralic fine - grains of loess , such explanations as light bleaching , preheat , anomalous fading , prior - ir exposure were investigated in this paper . for drawing adequate coarse grains from loess , quartz and feldspars , as well as loess , were etched by hydrofluoric acid and fluorosilicic acid . the sequence of ages of holocene loess in weihe rivier basin has been established by single - aliquot ( sar ) and multiple - aliquot using fine - grains and sar using coarse - grains 本文通过渭河流域全新世黄土的光晒退实验，地表黄土样品的d _ e值测定，细颗粒单片的预热、反常衰退、红外暴露实验，说明释光测年在全新世黄土中应用的可行性及单片再生剂量法( sar )在黄土细颗粒中的适用性；为了从黄土中分离出足够的粗颗粒，进行了纯石英和长石的氢氟酸( hf )和氟硅酸( h _ 2sif _ 6 )溶蚀实验，黄土粗颗粒石英溶蚀分离实验；通过细颗粒单片、多片的blsl 、 irsl和post - irosl ，热释光，及粗颗粒石英的blsl的年代测定，选择适于全新世黄土的释光测年方法，并建立了渭河流域全新世黄土的年代序列。
