"Parinacota 1". A hiatus of over 60,000 years occurred between the eruption of the "Chungará Andesites" and the formation of the lava dome plateau. Traces of explosive activity during the lava dome stage have been found. The "Chungará Andesites" have a volume of over ; material from these stages was incorporated in the collapse deposit. Pomerape volcano developed during this time as well. This and the long delay between the eruption of the Chungará Andesites and the rest of the volcano's history may imply that the magmatic systems involved were different. Magma output during the early stage was low, with a magma output of with the dome growth contributing . Old Cone and sector collapse At the same time as the lava domes were emplaced, the Old Cone started growing a short distance northwest of the domes. The temporal gap between this stage of Parinacota's activity and the previous one may be because the deposits from this time interval are only poorly preserved. The Old Cone developed over 85,000 years until the sector collapse, and is also known as Parinacota 2. Outcrops of this stage are found mostly low on the southeastern and north-northwestern slopes; individual dates obtained on rocks from this stage are 20,000 ± 4,000, 46,700 ± 1,600, and 53,000 ± 11,000 years ago. The "Border Dacites" also belong to this stage, being dated at 28,000 ± 1,000 years ago. Likewise, ash fall deposits found in the Cotacotani lakes have been dated to this period of volcanic history, indicating that the Old Cone occasionally featured explosive eruptions. This stage erupted andesite and dacite in the form of three distinct suites. Magma output during this time was about . This also was a time of glacier growth and development in the region, and consequently a glacier cap developed on the Old Cone during this time. By the time of the sector collapse, the glaciers were already retreating. The date of the collapse is not known with certainty, because dates have been obtained on various materials with different stratigraphic interpretations. 18,000 years ago was considered the most likely estimate, but ages as young as 8,000 years ago were also proposed. Radiocarbon dates from peat within the collapse deposit indicated an age of 13,500 years ago, or 11,500–13,500 years ago. Many dates were obtained on material predating the collapse that was embedded within the collapse deposit, and thus the most likely