Tepetate (Spanish tepetate; Nahuatl tepetlatl) is a Mexican term for a geological horizon, hardened by compaction or cementation, found in Mexican volcanic regions.[1] Tepetates at the surface are problematic for agriculture, because of their hardness, poor drainage, and poor fertility. When tepetates lie under the soil, they present a risk for erosion and landslides, because water runs off laterally, rather than being absorbed.