Qihulin Fm

E. Heilongjiang – Wandashan. Lower-Middle formation of Longwangzhang Gr. The type section is visible along the Qihulin River.

"Fossilifereus marine strata with some nonmarine intercalations consist of thick-bedded black mudstone, fine-grained sandstone and tuff. The total thickness of the forrnation is about 750 m."

The mudstone beds in the upper part of this formation yield abundant marine fossils; ammonites, bivalves, gastropods, brachiopods, crinoids and plants. Barremian ammonites as well as lower Aptian ammonites in the uppermost part. Barremian-Aptian bivalves, including Aptian Thracia rotundata, Barremian-Aptian Filosina subovalis, and Palaeonucula makitoensis, Entolium inequivalve, Thracia shokawensis, a middle Barremian-Aptian dinoflagellate cysts assemblage consisting of Oligosphaeridium, Odontochitina operculata, Gardodinium trabeculosum and Palaeoperidinium cretaceum. a mainly Aptian-Albian foraminiferal assemblage consisting of Ammosiphonia [=“Cribrostomoides”] nonioninoides, Haplophragmoides gigas minor, H. multiformis and Trochammina depressa, and some radiolarians such as Novixitus.

The flora assemblage of the Qihulin Formation is dominated by ferns and conifers. It is similar to the Late Assikaevka flora assemblage. Both assemblages are characterized by domination of ferns and conifers. The common taxa are represented by Coniopteris, Gleicenites, Pterophyllum, Podozamites, Pityophyllum, Onychiopsis psilotoides [=O. elongata], Nilssonia ex gr. brongniartii [=N. sinensis], Osmunda denticulata [¼Cladophlebis denticulata], Dicksonia concinna [=Coniopteris saportana], Cladophlebis, Taxites (Cephalotaxopsis). The main difference is that the Late Assikaevka assemblage contains early angiosperms.

Littorial and sub-littorial.