The Guaduas Formation (Spanish: Formación Guaduas, K2P1G, K2E1G, KPgg, KTg, TKg, Ktg) is a geological formation of the Middle Magdalena Basin and the Altiplano Cundiboyacense, Eastern Ranges of the Colombian Andes. The predominantly shale with coalbed formation dates to the Late Cretaceous and Paleogene periods; Maastrichtian-Paleocene epochs, and has a maximum thickness of 1,090 metres (3,580 ft). Fossils of Coussapoa camargoi, , and have been found in coalbeds in Zipaquirá and Tasco, Boyacá.