【摘要】 根据南京长江大桥、三桥、四桥的地质钻孔资料,绘制南京段长江古河槽地质剖面示意图,对拟建南京长江四桥附近的4个钻孔进行了采样分析,从钻孔沉积物样品的14C年代及阶地形成时间可以判断,南京段约-60~-90 m的深槽为末次盛冰期时的长江河槽,钻孔揭示,南京段长江古河槽狭窄陡峭,呈V型,在南京长江大桥附近形成局部深切。更多还原

【Abstract】 Three cross sections of paleovalley depositional sequences were established based on bore data and documents of Nanjing No.3 Bridge,the Yangtze River Bridge and Nanjing No.4 Bridge.Through 14C dating to samples from 4 drilling cores near the Nanjing No.4 Bridge which is proposed to construct,it is discovered that the paleovalley at the-60~-90 m depth near Nanjing existed within the period of last glacial maximum.It is also indicated that the deep incised-valley channel was narrow and the river flowed swiftly.Drilling shows that the valley channel ran deep locally near the Nanjing Yangtze River Bridge,like a "V" shape.更多还原