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对长江三角洲顶部ZKA4钻孔第四纪地层的粒度特征进行了系统细致的分析,结合年代学、岩性特征、沉积构造、孢粉以及有孔虫数据,对长江三角洲顶部地区的古环境古气候进行了研究。通过对ZKA4钻孔的岩性特征、沉积构造、有孔虫以及粒度特征进行分析,ZKA4孔主要发育河流相、冲积扇相以及河口湾相,钻孔从底至顶依次为河流-冲积扇-河流-冲积扇-河流-河口湾-河流沉积。粒度参数以及典型孢粉组合在钻孔垂向上的变化反映出ZKA4孔在13.71~12.48ka(46~42m)之间发生了一次明显的降温事件,为急剧升温过程中的一次快速降温变冷的气候事件,这是长江三角洲顶部地区对新仙女木事件的响应,持续时间约为1230年。
The grain characteristics of the Quaternary stratigraphy in the ZKA4 borehole at the top of the Yangtze River Delta are systematically and carefully analyzed. Based on the chronology, lithology, sedimentary structure, sporopollen and foraminiferal data, the paleoenvironment paleoclimate Were studied. By analyzing the lithology, sedimentary structure, foraminifera and grain size of ZKA4 boreholes, ZKA4 mainly develops fluvial facies, alluvial fan facies and estuarine facies. From bottom to top, the boreholes are river-alluvial fan- River - alluvial fan - river - estuary - river sediment. The variation of grain size and typical sporopollen assemblages in vertical borehole shows that a significant cooling event occurs in ZKA4 between 13.71 and 12.48 ka (46 and 42 m), which is a rapid cooling and cooling in the rapid warming process The climate event, which is the response to the new fairy wood event at the top of the Yangtze River Delta, lasts for about 1230 years.