Coquena formed along an outer ring fault. The caldera wall reaches its highest height in the area of Corral de Coquena.: The basement beneath Corral de Coquena is slightly higher than the general Pacana caldera floor.: The ring belongs to the post-caldera activity phase of La Pacana. The dating is uncertain; the ring is constructed on top of the Pampa Chamaca ignimbrite (2.4 mya) but one date obtained from the ring is 4.4 ± 0.3 mya, obtained on biotite.: The date of the ring is more likely to be incorrect. Other estimates indicate that Pampa Chamaca overlies the Corral de Coquena deposits,: an as yet unsettled question. The Atana ignimbrite that clearly pre-dates the Coquena ring has been reassessed as being 3.9-4.2 ± 0.1-0.2 mya old, reducing the estimated age of Corral de Coquena as well.: