胶莱盆地莱阳群杨家庄组沉凝灰岩SHRIMP U——Pb年代学特征及地质意义

Chronological Characteristics and Geological Significance of SHRIMP U Pb of Sedimentary Tuff in Yangjiazhuang Formation of Laiyang Group in Jiaolai Basin

摘要:

胶莱盆地为一发育于华北陆块东部的白垩纪断陷盆地，该次工作主要对盆地底部莱阳群杨家庄组中沉凝灰岩层进行了初步研究，通过对沉凝灰岩岩石学、锆石SHRIMP UPb年代学的研究，认为胶莱盆地莱阳群杨家庄组中凝灰岩层形成时代为131.1±1.7Ma，限制了莱阳群杨家庄组的沉积时限，为胶莱盆地早期的形成与演化提供了新的年代学依据。沉凝灰岩中获得单颗碎屑锆石年龄为835±23Ma，指示苏鲁造山带为莱阳群提供了物质来源。

Abstract:

Jiaolai basin is a Cretaceous graben basin developed in the eastern part of North China block. A preliminary study of the sedimentary tuff layer in Yangjiazhuang formation of Laiyang group at the bottom of the basin has been carried out. Through study on petrology of sedimentary tuff and zircon SHRIMP U-Pb chronology study, it is regarded that the formation age of the tuff layer in Yangjiazhuang formation of Laiyang group in Jiaolai basin is (131.1±1.7)Ma. It limits the sedimentary time of Yangjiazhuang formatio, and provides a new chronological basis for the early formation and evolution of Jiaolai basin. The age of the single detrital zircon in the sedimentary tuff is (835±23)Ma. It is indicated that Sulu orogen provides a material source for Laiyang group.