根据区域调查和对南京江北剖面沉积物及埋藏古树和炭化木的年代测定,以及对孢粉、粒度、石英砂表面特征鉴定分析,发现本区存在晚北方期至亚北方气候期(8200±126aBP、7822±250aBP～7670±160aBP、7562±90aBP、4085±95aBP～4090±100aBP以及3730±90aBP)具有洪积特征的天然剖面地层,该剖面位于长江北岸二级阶地上,其洪积层系由古洪水期长江摆动时沉积所致。剖面上部厚0.53m的灰黄色土层系在亚北方期大约3000aBP～2850aBP的寒冷期中主要由风尘搬运堆积所致。

Field investigations and analyses of sediments, buried paleo-trees, gagatite, sporopollen, granularity, quartz-sand surface feature, oxide and chronology found a natural profile with pluvial characteristics during the Late-boreal phase to Subboreal phase (8 200±126 aBP, 7 822±250 aBP~7 670±160 aBP, 7 562±90 aBP, 4 085±95 aBP~4 090±100 aBP and 3 730±90 aBP). The sporopollen with more thermophilous coniferous-broad plant communities in the profile illustrates that the humid-hot climate should be a major climate during the period from 8 200±126 aBP to 3730±90 aBP. A large number of agatite, buried paleo-trees and sand-gravel with pluvial feature between the third layer and the ninth layer indicate that the period has experienced many times flood environments with megathermal pluvial climate. The investigation shows that the profile is situated in the second terrace on the north bank of the Yangtze River, its pluvial layer should be formed by the Yangtze River swinging and depositing during the paleo-flood period. In addition, the grey-yellow loess layer with thickness of 0.53m in the upper of the profile should be formed by dust transporting and accumulation during the cold period (3000 aBP~2850 aBP) of Subboreal phase by the analyses.