The Tuerto Formation consists primarily of conglomerate with minor sandstone. The clasts (rock fragments) making up the conglomerate consist largely of hornfels and Ortiz porphyry eroded off the Ortiz Mountains and Cerillos Hills and deposited as a thin alluvial fan in the Hagan basin. Beds containing limestone clasts eroded off the east slopes of the Sandia Mountains are sometimes also included in the formation. The formation is informally divided into a lower well-cemented cliff-forming member and an upper poorly cemented member.