通过光释光断代仪对宁夏长城塬黄土土壤剖面7个样品进行年代测定,获得7个确切的地层年代值。结果表明:约12 580 a BP,剖面处于气候干旱时期,形成马兰黄土(L1);约11 498 a BP,剖面处于全新世升温过渡期,形成过渡层(Lt);6 731~2 827 a BP,剖面处于全新世大暖期,形成古土壤(S1);约1 394 a BP,剖面处于相对干旱时期,形成全新世黄土(L0)。
Based on filed survey, the very typical Holocene loess strata were found on the Changchengyuan Loess Tableland in Pengyang, Ningxia Hui Autonomous Region. Seven samples were collected from a Holocene loess-paleosol profile in the study area. The dating of these samples was tested using the optical stimulated luminescence dating. The results show that Malan loess formed around 12.58 ka BP. when it was drought; the transitional loess formed around 11. 498 ka BP. when it was relatively warm; the paleosol formed during the periods of 6. 731 ka BP. and 2. 827 ka BP. when it was very warm ; the Holocene loess formed around 1. 394 ka BP. when it was drought again. The results are similar to the dating data of MJY profile and ETC profile, so they are reliable.