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characterized by a structural style of half-graben with a northern faulting and southward
overlaping. The Depression can be divided in to three structural belts: a northern steep belt
(NSB), a middle sag belt (MSB) and a southern slope belt (SSB) (Fig.1c). During the lower
Es4 Formation in the early Paleogene, under the controlling of the northern Chenjiazhuang
boundary extensional fault, many nearshore subaqueous fans developed in the footwall of
the Chenjiazhuang major fault along the northern steep belt and extending into the deep
and semi-deep lacustrine facies of the middle sag belt (Fig.1d) with sources mainly from the
northern Chenjiazhuang Uplift (Gao et al., 2008; Xie et al., 2004; Yan et al., 2005) (Fig. 1). The
burial depth of these subaqueous fans now reaches more than 3500m.
Facies analyses shows that the Dongying nearshore subaqueous fan consists of three sub-
facies including a root sub-fan, a mid sub -fan and a marginal sub -fan (Gao et al., 2008; Song,
2004; Yan et al., 2005). The root sub-fan is composed by one or more major channel
Fig. 2. The single-well facies analysis of well f8 shows that the 4th member of the lower Es4
Formation is a nearshore subaqueous fans with three sub-facies (modified from Gao et al.,
2008; Song, 2004; Yan et al., 2005).
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