Campo de Piedra Pómez
Interesting facts
- Cerro Blanco's eruption of about 4,200 years ago has been tentatively rated VEI 7, the largest known Holocene eruption in the Central Andes.
- That eruption was larger than Peru's 1600 Huaynaputina eruption, the biggest volcanic event recorded in the region's history.
- Cerro Blanco is considered the youngest caldera of the Central Andes, and its floor still releases steam from fumaroles at around 94 °C.
- Satellite radar shows the Cerro Blanco caldera has been slowly sinking, by roughly a centimetre a year, since at least 1992.
- Geologists have compared the giant wind ripples of the neighbouring valleys with ripple fields on Mars.
- The yardangs and hoodoos fill an area of roughly 25 by 5 km, their sides fluted by sand-laden wind.
- The protected area covers about 75,500 hectares, ranging in altitude from about 3,050 to 4,850 metres.
- The field lies on the Puna, part of the Altiplano-Puna, the second-largest high plateau on Earth after Tibet.
- Ash from Cerro Blanco appears in nearby archaeological sites, and at one cave human activity changed after the eruption.
Why it is worth it
Campo de Piedra Pómez is a pale stone sea stranded high on the Puna of north-western Argentina: thousands of white and pinkish pumice fins, blades and towers rising from dark volcanic sand, every one of them shaped by the wind. The field lies in Catamarca Province, just north of the Cerro Blanco volcanic complex, on the border between the Antofagasta de la Sierra and Tinogasta departments.
The rock is young by geological standards. Around 4,200 years ago Cerro Blanco produced one of the largest eruptions of recent millennia in the central Andes, spreading roughly 170 km³ of ash and pumice over some 500,000 km² — the layer is still about 20 cm thick in Santiago del Estero, 370 km to the east. The field itself lies on an older ignimbrite sheet from earlier eruptions of the same volcanic system, laid down tens of thousands of years before. That soft, porous deposit is the raw material of the field.
The sculptor is the relentless wind of the high plateau. Carrying sand and grit, it has cut the ignimbrite into yardangs — streamlined ridges lined up with the prevailing wind — and into hoodoos and bare cliffs. Typical forms are 2 to 20 m wide and up to about 10 m tall, and in places the wind has scoured channels 20 to 25 m deep. In the neighbouring Carachipampa and Purulla valleys the same winds have piled gravel into ripples up to 2.3 m high and 43 m apart, the largest wind ripples known anywhere on Earth.
The field is protected as the Campo de Piedra Pómez Natural Protected Area of Catamarca Province and belongs to a Ramsar site covering the high Andean and Puna lakes of the province. In 2019 it was one of the finalists in a national contest to choose the Seven Wonders of Argentina.
Getting there
The nearest town of any size is Belén, about 120 km away in a straight line. The usual base is the small settlement of El Peñón on Route 43, some 220 km by road from Belén and 63 km north of Antofagasta de la Sierra; from El Peñón a track of roughly 40 km leads to the field. The closest airport as the crow flies, Ricardo García Posada Airport (ESR) at El Salvador in Chile, is about 228 km away but on the far side of the Andes; within Argentina the nearest is Teniente Benjamín Matienzo International Airport (TUC) in San Miguel de Tucumán, about 240 km in a straight line.
On these lists
-26.65972, -67.51417per Wikidata