Provenance Analysis of Dainan Formation (Paleogene) of Majiazui in Gaoyou Sag,Subei Basin

Synthesizing methods of clastic constituments,heavy mineral,and sedimentation,we analyzed Dainan Formation provenance of Majiazui in Gaoyou Sag,Subei Basin.Igneous rock is the main lithology of Majiazui source rocks,followed successively by metamorphics and sedimentary rock;distribution range of neutral and acidic igneous rocks is wider than that of basic igneous rock;and medium to low is the dominating grade of metamorphics;while plutonite here is rare.According to sandstone types,types and contents of clastic constituents,percentage of sandstones,thickness of layers,distribution of sedimentary facies,stability factors of heavy minerals,heavy mineral combination,ZTR index and index of heavy mineral,we believe that during the depositional period of Dainan Formation,provenance differed between different blocks.Sediments of Ma 8 block mainly from Lingtang low bulge and partly came from Tongyang uplift;that of Ma 31 block was only from Lingtang low bulge and paleo-rivers transferred;while sediments of Ma 33 block came from Tongyang uplift.