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北京十三陵中、新元古界沉积厚度巨大(4278 m),笔者通过对关键界面的识别和沉积体系域配套的原则,在其内识别出19个层序。在此基础上对高于庄组的4个层序、杨庄组的1个层序、雾迷山组的2个层序和铁岭组的1个层序的层序界面和层序内部碳、氧同位素进行了系统测定,得出如下认识:北京十三陵中、新元古界δ~(13)C值为-2.6‰～0.81‰,δ~(18)O值为-8.8‰～-2.8‰。在层序界面上、下,一般表现为δ~(13)C值由负异常向正异常方向迁移,δ~(18)O值由正异常向负异常方向迁移。δ~(13)C演化机理是:每层序底部均为一次新的海平面上升期沉积,在此期间,藻类生长速度较快,沉积速率高,有机质与外界接触时间短暂,使有机质在尚未被氧化前就被迅速埋藏。因此,有机碳埋藏速率较高,造成一个相对较高的δ~(13)C值;层序顶部反映了海平面的下降和地表暴露事件的发生,在此期间藻类生长速度减慢,甚至停滞,并且由于海平面下降,水体变浅,有机
Among the Ming Tombs in Beijing, the Neoproterozoic sediments were huge (4278 m) thick. The authors identified 19 sequences within the framework by identifying the key interfaces and supporting the sedimentary system domain. On this basis, the four sequences of Gaoyuzhuang Formation, one sequence of Yangzhuang Formation, two sequences of Wumishan Formation and one sequence of Tieling Formation, and the sequence carbon , Oxygen isotopes were systematically determined and the following findings were obtained: The δ 13 C value of the Neogene Paleocene in Beijing was -2.6 ‰ ~ 0.81 ‰ and the δ ~ (18) O value was -8.8 ‰ ~ -2.8 ‰. At the sequence boundary of the sequence, δ ~ (13) C values generally migrate from negative anomalies to positive anomalies and δ ~ (18) O values migrate from positive anomalies to negative anomalies. The evolution mechanism of δ ~ (13) C is that the bottom of each sequence is a new sedimentation in sea level rising period. During this period, the algae grow faster and have higher sedimentation rate, and the contact time of organic matters with the outside world is short, Was quickly buried before being oxidized. Therefore, the burial rate of organic carbon is relatively high, resulting in a relatively high δ ~ (13) C value. The top of the sequence reflects the decrease of sea level and the occurrence of surface exposure events. During this period, algae growth slowed down or even stopped , And due to the sea level decline, water shallow, organic