This paper makes a study of the mixed clasticcarbonate deposits widely distributed in the lower part of the 1st member of the Shahejie Formation

Huanghua Depression. Since there is little research on this kind of mixed deposits

it is hard to identify sedimentary facies

reservoir distribution

poolforming elements and their distribution patterns. Therefore

by examining sedimentary microfacies and based on the sequence stratigraphic framework of the study area

we made a comprehensive study of petrologic features

genetic types and evolutionary patterns of mixed clasticcarbonate deposits and the controlling effect of sequence stratigraphic framework on their distribution. According to this study

we recognize four types of mixed deposits: parent material mixing

 mixing due to gradual facies change

insitu mixing and gravity flow mixing. The mixed deposits are highly developed in lowstand system tract

but poorly developed in highstand and transgression system tracts. The lower part of the 1

st

member of the Shahejie Formation

Huanghua Depression

is a typical example of modern mixed clasticcarbonate deposits. Results from this study can provide thoughts and foundations for further exploration and development in the study area.