Silurian rocks are missing, and the Lower Devonian-Mississippian Caballos Novaculite rests unconformably on the Upper Ordovician Maravillas Formation. More than 1.4 km of flysch, from a source to the southeast, forms the Mississippian-Pennsylvanian Tesnus Formation. No Paleozoic rock younger than Early Pennsylvanian (Morrowan Series) have been found. The measured thickness of Paleozoic rocks in the Solitario is approximately 2.6 km and represents a time span of 240 m.y. with a single break of ~30 m.y. during Silurian, one of the longest depositional records known. The Paleozoic rocks found in the Solitario are allochthonous and were intensely deformed during the Ouachita Orogeny. The orogeny affected the Solitario area from Middle Pennsylvanian (Desmoinesian) until Early Permian (middle Wolfcampian). Transport of the allochton during the Ouachita Orogeny was at least tens of kilometers from the southeast.