Abstract:

Mesozoic fan delta facies in Ying'er Depression,Jiudong Basin developed well.It's sedimentation is brisk and fluid types are abundant.Sediments are mainly sheet grain flow deposit associated with sheet tractional deposit.The fan delta deposits in the region are distributed close to active boundary faults to the north and east of the basin.It's sedimentary facies belt,including fan delta plain,fan delta front and pre fan delta subfacies,developed completely.In vertical direction,the fan delta is a set of retrograding ingression lacustrine sequence with coarse sediments in the lower part and fine ones in the upper part,suggesting that subsiding velocity of lake basin surpassed sedimentary compensation velocity.The sandstones and conglomerates of fan delta facies and dark mudstone of deeper lake subfacies are paragenous in the region.In addition,sedimentary sequence of mudstone and dolostone of lake facies is continuous in Upper Mesozoic and its thickness is big.They constitute a set of complete source reservoir cap rock assemblages.