It consists of an alteration of pale red to yellowish-gray, fine to medium-grained sandstone and grayish-reddish brown siltstone and clay.

Rare pale red to light gray conglomerates, containing carbonate pebbles, are also characteristic of this formation.

This geological formation in Thailand dates to the Early Cretaceous age, specifically the Valanginian through Hauterivian stages.

[2] Baser on paleosols and lithostratigraphy, the Sao Khua Formation is believed to have been deposited in a warm to slightly cool semi-arid climate by a meandering river system.

[citation needed] Geochemistry is indicative of a stable humid subtropical climate regime, and sedimentation is thought to have occurred in a floodplain setting which was fed by bedload-rich large meandering channels.