CAJ | 학술논문

浙江东南部中生代晚期火山地层可划分为三个火山旋回，通过对不同层位火山岩Nd同位素组成的研究，得出结果：第一至第三旋回火山岩(自下而上)εNd (t)值依次为-14.1～-6.2，平均-9.9；-7.7～-6.4，平均-7.0及-7.5～+0.1，平均-4 .6。t2DM值依次为1.6～1.8Ga,平均1.7Ga; 1.4～1．6Ga，平均1 .5Ga及0.9～1.5Ga，平均1.3Ga。由此可见，在不同的火山旋回之间具有明显的Nd同位素组成特征差异，它反映了该区中生代晚期火山活动随时间的推移，在构造环境和岩浆来源上所发生的有序变化，从而，Nd同位素示踪信息也就有可能作为火山地层划分和对比的重要依据之一。
절강동남부중생대만기화산지층가화분위삼개화산 선회 ，통과대불동층위화산암Nd동위소조성적연구，득출결과：제일지제삼선회화산암(자하이 상)εNd (t)치의차위-14.1～-6.2，평균-9.9；-7.7～-6.4，평균-7.0급-7.5～+0.1，평 균-4 .6。t2DM치의차위1.6～1.8Ga,평균1.7Ga; 1.4～1．6Ga，평균1 .5Ga급0.9～1.5Ga，평균1.3Ga。유차가견，재불동적화산선회지간구유명현적Nd동위소조 성특정차이，타반영료해구중생대만기화산활동수시간적추이，재구조배경화암장래원상소 발생적유서변화，종이，Nd동위소시종신식야 취유가능작위화산지층화분화대비적중요의거지일。
Late Mesozoic volcanic rocks in southeastern Zhejiang P rovince can be subdivided into three stratigraphic cycles.The εNd(t) values for these three cycles,from bottom to top,are -14.1 to -6.2,with an average of -10.0; -7.7 to -6.3,with an average of -7.0; and -7.5 to 0,with an average of -4.6,respectively.T2DM for the three cycles are 1 .6 to 1.8,with an average of 1.72Ga; 1.4 to 1.6,with an average of 1.48Ga; and 0.9 to 1.5,with an average of 1.31Ga,respectively.Volcanic rocks from different cycles show significant variation in Nd isotopic compositions,indicating th at the tectonic environment of formation and the magma source of volcani c rocks varied with time.Therefore,Nd isotopic compositions of the volcani c rocks are very important in stratigraphic division and comparison.