山东蓬莱、栖霞、沂水、临朐等地分布大片新生代玄武岩。过去主要根据其下伏松散沉积层的时代,与临朐中新统山旺组对比,划分为中新世下玄武岩和上新世上玄武岩。 1972年作者之一,在蓬莱一带发现玄武岩覆盖在第四纪黄土层之上,使黄土受到明显烘烤,又在多处发现玄武岩覆盖在不同高度的剥蚀面及松散沉积层之上,这不仅表明本区有第四纪玄武岩和火山产物存在,而且反映新第三纪以来有多期活动的特点。据此,曾将本区玄武岩活动分为四期: Shandong Penglai, Qixia, Yishui, Linqu and other places large tracts of Cenozoic basalts. In the past, mainly in the era of its unconsolidated sediments, it was divided into basalts of the Miocene and Pliocene basalts in contrast to the Xidan Shanwang Formation in Linqu. In 1972, one of the authors found that basalt covered the Quaternary loess layer in the area of ​​Penglai, which obviously baked the loess and found that basalt was covered on different levels of denudation surface and loose sediment in many places, not only This indicates that there are Quaternary basalts and volcanic products in this area, but also reflects the characteristics of multi-period activities since the Neogene. Accordingly, basalt activities in the area had been divided into four phases: