Jindong Formation

The Jindong Formation is a geological formation located in South Korea. It dates to the Cenomanian stage of the Late Cretaceous, with a maximum depositional age of 99.9 ± 0.7 Ma.
Lithology.
The formation is a thick layering of fine-grained, altered volcaniclastic sediments. Most of these sediments are ash-rich mudstone, siltstone, and very fine sandstone. There is also coarser sandstone, conglomerate, carbonates, and ash tuff. 
Paleontology.
The area has many dinosaur and bird tracks. It contains "Caririchnium kyoungsookimi", the first trackway of a quadrupedal ornithopod discovered in Korea.