Early Cretaceous Qingshan stage ( Aptian - Albian ) volcanic-sedimentary and stratigraphic correlation in Lingshan island - Jimiya region，Eastern Shandong coastal area，China

In the Late Mesozoic, there is a NE-trendiing rift basin forming with the subduction of the Pacific plate in eastern Shandong coastal area, China. In Early Cretaceous QingShan stage, the volcanic-sedimentary sequence in... [ view full abstract ]

In the Late Mesozoic, there is a NE-trendiing rift basin forming with the subduction of the Pacific plate in eastern Shandong coastal area, China. In Early Cretaceous QingShan stage, the volcanic-sedimentary sequence in Lingshan Island (from base to upper): White rhyolite, Terrigenous clastic rock with pyroclastic flow interlayer, pyroclastic rocks, Andesite; while the volcanic-sedimentary sequence of Jimiya region: Rhyolitic tuff, Andesite pyroclastic rock, Silty mudstone, Andesite. The rhyolite samples from Laohuzui of Lingshan island were dated using zircon LA-ICP-MS method, yielding the weighted mean 206Pb/238U age of (119.2 ± 2.2) Ma which is coincident with the beginning of the volcanism of the Qingshan stage. With the study of volcanic-sedimentary in Qingshan stage and the stratigraphic correlation in these two areas, the volcanic-sedimentary succession of Late Mesozoic Early Cretaceous in research area can be divided into three sections from old to new: 1st: white rhyolite、rhyolitic tuff; 2nd: terrigenous Clastic Rocks with pyroclastic flow interlayer; 3rd: andesite, pyroclastic rocks with sedimentary rocks interlayer. The comprehensive analysis shows the palaeogeomorphology pattern of the research area in Early Cretaceous QingShan stage : southeast high (shallow) - northwest low (depth).The petrography study shows that the volcanism in Qingshan stage is multi-cycle、multi-episode and multi-stages, mainly eruption pattern: erupts on land, deposits on land & underwater, the eruption pattern involves phreatomagmatic explosions and phreatic explosions. This study establishes a volcanic-sedimentary sequence of Shandong coastal area in early Cretaceous, and means the basin revolution comes into the volcanic basin period gradually.