As you continue to drive east on the international road toward Argentina, the Atana ignimbrite changes its dip direction. Its dominant dip direction was west and it suddenly dips to the east, suggesting that the road crosses over the La Pacana caldera.
There is an obvious exposure along the international road that is a great indroduction to the deposits that dominate the northeast region of Chile. When looking to the south, the lowermost unit is the Atana ignimbrite, 4.09 Ma. Above the Atana is a fall deposit that is overlain by the Tara ignimbrite, 3.68 Ma. The Filo Delgado ignimbrite is the uppermost unit exposed.