Two radioisotopic dating methods are applied to Quaternary fluviolacustrine detritus deposits in the commune of Morsott in northeastern Algeria. The studied profile shows an open and contaminated environment. In the case of the shells of molluscs, the choice of identical samples for both the dating methods is wise. Obtained results are different; thus, positioning the chronology of the Quaternary sequence is difficult. The uranium–thorium (U–Th) series technique gives a younger age than that provided by radiocarbon (¹⁴C) in Holocene. For carbonates at the base of the study sequence, the age difference is 278,154 ka BP. In the lowermost level of limestone crusts in the last Pleistocene, ¹⁴C gives a younger age than that provided by the U–Th series technique, rendering the chronological order of the levels inconsistent. Despite the corrections of the U–Th series technique and the age calibrations of ¹⁴C, this method is recommended for open systems (environments). Contamination related to either post depositional parameters or sample preparation techniques is certain in this type of open environments. In open environment applications, the reliability of the U–Th series or ¹⁴C technique changes from the upper to the bottom of the studied series as the function of various external parameters. For this reason, including other techniques is necessary to confirm and understand the chronology of Quaternary.

两种放射性同位素测年方法被应用于阿尔及利亚东北部莫索特公社的第四纪氟湖石碱碎屑沉积物。所研究的轮廓显示出一个开放且受污染的环境。对于软体动物的壳，为两种测年方法选择相同的样品是明智的。获得的结果是不同的；因此，很难定位四元序列的年代。铀-series（U-Th）系列技术比全新世的放射性碳（¹⁴ C）提供更年轻的年龄。对于研究序列底部的碳酸盐岩，年龄差异为278,154 ka BP。在最后一次更新世中，最下层的石灰岩地壳中，¹⁴C给出的年龄比U–Th系列技术提供的年龄要小，从而导致水平的时间顺序不一致。尽管对U–Th系列技术进行了校正，并且对¹⁴ C进行了年龄校准，但仍建议在开放系统（环境）中使用此方法。在这种类型的开放环境中，与沉积后参数或样品制备技术相关的污染是确定的。在开放环境应用中，U–Th系列或¹⁴ C技术的可靠性随所研究系列的不同而从上至下变化，这是各种外部参数的函数。因此，需要使用其他技术来确认和理解第四纪的年代学。