CAJ | 학술논문

南堡凹陷古近系火山岩经历了两个裂陷旋回、4个喷发幕。对火山岩锆石形貌、SHRIMP和LA-ICPMS U-Pb年龄测定及Lu-Hf同位素研究结果表明，岩浆旋回早期的锆石95％以上为变质重结晶形成，U-Pb年龄变化大，主要来自1800 Ma前碰撞花岗岩地壳，它是中、新太古代（2900～2600 Ma）新生地壳与古洋壳碰撞引起的重熔和再循环过程而形成的。岩浆旋回中、晚期锆石为幔源原岩浆溢出结晶而成，含岩浆锆石和较丰富的俘虏晶，有利于进行锆石年代学和同位素研究。通过这些锆石年龄，建立了南堡凹陷和华北克拉通相对应的构造热事件的垂向序列，同时准确标定了幔源岩浆溢出和相关地层的绝对年龄。南堡凹陷的馆陶组属于新近系中新统，东营组属于古近系渐新统，而沙河街组跨越古近系的古新统和始新统。
남보요함고근계화산암경력료량개렬함선회、4개분발막。대화산암고석형모、SHRIMP화LA-ICPMS U-Pb년령측정급Lu-Hf동위소연구결과표명，암장선회조기적고석95％이상위변질중결정형성，U-Pb년령변화대，주요래자1800 Ma전팽당화강암지각，타시중、신태고대（2900～2600 Ma）신생지각여고양각팽당인기적중용화재순배과정이형성적。암장선회중、만기고석위만원원암장일출결정이성，함암장고석화교봉부적부로정，유리우진행고석년대학화동위소연구。통과저사고석년령，건립료남보요함화화북극랍통상대응적구조열사건적수향서렬，동시준학표정료만원암장일출화상관지층적절대년령。남보요함적관도조속우신근계중신통，동영조속우고근계점신통，이사하가조과월고근계적고신통화시신통。
Nanpu Sag underwent two magmatic cycles and four episodic eruptions .Zircons of volcanic rocks from Nanpu Sag are dated by U-Pb SHRIMP,LA-ICPMS and Lu-Hf isotope method.The results indicate that more than 95%of zir-cons in the early magmatic cycle are formed by metamorphic recrystallization ,with a big range of U-Pb age.It is explained that they are formed by collision granite crust in 1 800 Ma,which is caused by remelt and recycling process induced by collision between new crust of Middle and Neo-Archean (2 900~2 600 Ma) with palaeo-oceanic crust .In the middle to late magmatic cycle ,zircons are formed by crystallization of mantle-derived magma overflow , and they contain magmatic zircon and rich captive crystal ,which are helpful for chronology and isotope studies .Through those zircon ages ,a vertical sequence of correspondent tectono-thermal events of the North China craton and Nanpu Sag is established .Moreover ,the absolute ages of mantle-derived magma overflow and the related strata are calibrated accurately .The result shows that Guantao Formation belongs to Miocene ,Dongying Formation belongs to the Oligocene and Shahejie Formation crosses Pa-leocene and Eocene .