Aodi Fm

Xueshan range, north Taiwan. The type section is located at bathing beach in Gongcha and Fulong to southeast of Aodi Village and near the Fulung seawater swimming field; ~47 km east of Taipei, Taiwan. It was named by Yan C and Chen P in 1953. Original definition in Taibei County History in 1960.

Synonym: Aoti Fm

Predominantly gray, thick-bedded, medium- and fine-grained sandstone with dark gray shale or lime shale and coal beds, slightly metamorphosed. According to its lithological associations, it may be divided into the upper and lower parts. Lower part is equivalent to the “Magang Formation”, ~370 m thick, consisting principally of alternating beds of slightly metamorphosed gray and dark gray shale and gray and yellowish brown, massive, fine- and medium-grained quartz sandstone. Upper is equivalent to the “Fangjiao Member”, ~385 m thick, made up dominantly of alternating beds of gray, thick-bedded to massive sandstone and shale with thin coal beds and carbonaceous shale. Sandstone is compact with well-developed joints and shows an indistinct banded structure. Its thickness ranges from 700 to 1200 m.

The lower part of the formation contains small quantities of foraminifera such as Gaudryina hayasakai, Nonionella kankouensis, Miliolinella labiosa and Globigerina praebulloides.

It is interpreted as littoral or epicontinental marine environment.