Tianjialou Fm
Type Locality and Naming
Central Shandong. The Tianjialou Formation was erected by Li Qingping and Zhao Fengjiang in 1992. The section for the designation is from Dingjiagou to Youxinxing of the Dasheng Town of Anqiu City of Shandong (118°47′E; 36°18′N). Lower-Middle formation in the Wangshi Gr.
Lithology and Thickness
The Tianjialou Formation is represented by a set of variegated microclastic rocks, which is divided into three members. Frst member is mainly built up by dark purple and purple red fine-grained sandstone and silty mudstone, intercalated with purple red sandy conglomerate, andesite and dolomite. Second member is dark purple silty mudstone with andesitic sediment tuff and fine sandstone. Third member yellow is gray fine sandstone, siltstone, gray green mudstone and sandy mudstone. It is 1846.42 m thick.
Relationships and Distribution
Lower contact
The base of the formation marked by gray green mudstone is distinguished from dark purple andesitic conglomerate of the underlying Malanggou Fm.
Upper contact
The top marked by gray fine sandstone is distinguished from purple gray sandstone of the overlying Hongtuya Fm of Upper Cretaceous.
Regional extent
The formation is widespread and is mainly seen in Baoquan of Anqiu of the northern part and Tancheng of the southern part of west Shandong, measuring several hundred meters. In Xintai-Zibo area, represented by the Mengyin basin, it is represented by gray, gray green and gray yellow medium-coarse-fine-grained lithic arkose and siltstone, intercalated with montmorillonitized vitric tuff lies conformably on the underlying Qingshan Fm. In east Shandong it is most developed in the Jingzhi-Dadianzi small area, about 600 m in the Mazhuang area of Zhucheng, represented by yellow green siltstone and shale with gray purple siltstone, fine sandstone, micrite and micritic dolomite, contacting by fault with the underlying Malang Fm and conformably under the Siqiancun Fm. In the Zhucheng-Jiaozhou area, it is developed in the Jimo area, represented by purple, gray purple and purple red fine sandstone and siltstone, intercalated with tuffaceous sandstone and marl. The Tianjialou Fm is in conformable contact with both the overlying and underlying strata.
GeoJSON
Fossils
The formation yields gastropods Lioplacodes cf. cholaokyi, Viviparus sp.; bivalves Limnocyrena jeholensis; estheria Yanjiestheria sinensis, Y. qiancaoensis, Y. longa; sporopollen grains represented by the Cicatricosisporites- Classopollis- Exesipollis assemblage.
Age
Depositional setting
It belongs to shallow lacustrine-shore deposition.
Additional Information