河北平原南部曲周地区河间洼地沉积若干特征及相关问题——对吴忱等问题的回答

SOME CHARACTERISTICS OF THE INTERCHANNL-DEPRESSION DEPOSITS IN QUZHOU AREA, THE SOUTHERN HEBEI PLAIN AND RELEVANT ISSUES:A REPLY TO WU CHEN et al.

河北平原南部曲周地区一河间洼地剖面中 2 4 0cm ,1 6 0cm和 80cm深度处的AMS1 4C测年结果分别为1 0 2 1 0± 80aB .P .,82 70± 70aB .P .和 6 5 0 0± 6 0aB .P .。由这 3个测年数据和代用指标数据相结合推测的曲周地区全新世古环境状况及其变化与其他研究者在其他地区 ,尤为河北平原其他地区所获的结果是相同或相似的 ,并且在时间上是吻合的。由这 3个数据推导的沉积物的埋深、厚度、堆积速率以及岩性等特征大都是这一剖面所处沉积环境和构造活动部位的反映 ,与前人有关河间洼地沉积的基本特征及其影响因素的阐述是相符的。充分认识河间洼地沉积物的特征 ,尤为其与河道沉积等的差别 ,对于更全面。

AMS 14 C dating results for the three depths of 240cm, 160cm and 80cm in a sedimentary sequence from an inter channel depression in Quzhou area, the southern Hebei Plain are 10 210±80aB.P., 8 270±70aB.P. and 6 500±60aB.P. respectively Holocene palaeoenvironments and their changes inferred from the three datings and proxy data are the same or similar to those inferred by other investigators for other areas, particularly for other parts of the Hebei Plain. Characteristics of this sequence such as buried depth, thickness and deposition rate estimated from the three datings and lithologies may be virtually the manifestations of deposition environments and are in agreement with descriptions on general features and impact factors of inter channel depositions given by other investigators. Thorough recognizing characteristics of inter channel depositions, particularly their differences from those of channel ones, may further the understanding of fluvial systems.