Cordón del Azufre facts for kids
Quick facts for kids Cordón del Azufre |
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NASA Landsat composite image
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| Highest point | |
| Elevation | 5,481 m (17,982 ft) |
| Geography | |
| Location | Argentina, Chile |
| Parent range | Andes |
| Geology | |
| Age of rock | 0.3 ± 0.3 mya |
| Mountain type | Complex volcano |
| Last eruption | Unknown |
Cordón del Azufre is a large, inactive volcano found in the middle of the Andes mountains. It sits right on the border between Argentina and Chile. This volcano is made up of several volcanic cones and streams of hardened rock called lava flows. Its formation is due to two giant pieces of Earth's crust, the Nazca Plate and the South American Plate, slowly moving and pushing against each other. To its north, you can find the quiet Lastarria volcano and an area called Lazufre, which is slowly rising.
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Exploring Cordón del Azufre
This volcano is sometimes confused with its neighbor, Lastarria. Cordón del Azufre is located right on the border between Argentina and Chile. It features many lava flows and volcanic craters, covering an area of about 60 square kilometers. Imagine four large bowls (craters) lined up from north to south along a 5-kilometer-long ridge. This alignment might show a crack deep in the Earth.
Many smaller volcanoes have grown on Cordón del Azufre. These include monogenetic volcanoes (which erupt only once) and stratovolcanoes (cone-shaped volcanoes). Their lava flows have covered most of the main crater. On the eastern side, a large area of 25 square kilometers is covered by old lava. The newest part, called La Moyra volcano, sent lava flows 6 kilometers to the west and 3 kilometers to the east.
Other volcanoes are nearby. To the north are Atalaya, Azufre Oriental, and Lastarria. To the south are Chuta, the Cerro Bayo Complex, and the Los Colorados caldera. This whole area is very remote and has no people living there. The weather is dry, windy, and has big changes in temperature.
Cordón del Azufre is about 300 kilometers east of the Chile Trench. This is where one Earth plate slides under another. The area around Cordón del Azufre is also a bit higher than its surroundings. The land here has very few rivers or streams. This is because it's so dry, and old lava flows often block any water paths.
How the Volcano Formed
The Earth's surface is made of huge plates that are always moving. Off the western coast of South America, the Nazca Plate is slowly sliding underneath the South American Plate. This process is called subduction. This movement creates the many volcanoes found in the Andean Volcanic Belt. This belt includes different sections, like the Central Volcanic Zone (CVZ), which covers parts of Peru, Bolivia, Chile, and Argentina.
In the Central Andes, you can find many large calderas. These are huge bowl-shaped depressions formed when a volcano collapses after a massive eruption. Examples include La Pacana and Galán. Around Cordón del Azufre, there are about forty volcanoes that are relatively young. These volcanoes grew on top of older volcanic rocks. The entire region has become very high over millions of years. The oldest rocks deep down are from the Paleozoic era. A big crack in the Earth's crust, called the Pedernales-Arizaro thrust fault, is also close to Cordón del Azufre.
The rocks from Cordón del Azufre are mostly andesite and dacite. These rocks often look like they have small crystals mixed into a finer material. They contain minerals like hornblende and plagioclase. These rocks formed when hot, melted rock (magma) from deep inside the Earth mixed with the surrounding crustal material. Cordón del Azufre is also known for its sulfur deposits. These deposits are a source of sulfur found in places like Salar de Gorbea.
The Volcano's Past Activity
The rocks from Cordón del Azufre are all less than one million years old. Over time, the volcano's activity shifted. It moved from the craters in the north and south to the eastern lava flows. Eventually, the activity focused on the La Moyra area. Some lava flows on the eastern side are about 600,000 years old.
Scientists have not recorded any recent eruptions or even steam vents (called fumarolic activity) at Cordón del Azufre. However, the lava flows look fresh and dark. Also, dating methods show that the most recent lava flow is about 300,000 years old. This suggests that the volcano might have been active during the Holocene period, which is the last 11,700 years. Some ash and rock fragments (called pyroclastic deposits) from the youngest cone might even be from a historical eruption.
If Cordón del Azufre were to become active again, it would likely produce more lava flows and ash. Since there are no major roads or towns nearby, any future eruptions would not pose a threat to people. It is ranked as the 21st most potentially dangerous volcano out of 38 in Argentina.
The Rising Lazufre Region
Since the late 1990s (around 1996-1998), a large oval-shaped area of about 2,000 square kilometers has been slowly rising. This area is located between the Lastarria and Cordón del Azufre volcanoes. It has been named "Lazufre," combining parts of the names Lastarria and Azufre. Sometimes, the Cerro Bayo Gorbea volcano is also included in this region.
Lastarria, Cordón del Azufre, and Cerro Bayo Gorbea seem to have cracks that spread out from the center of this rising Lazufre area. This rising area is surrounded by a ring of younger volcanoes. Scientists think it might be a caldera that is still forming. The uplift might have started because of several large earthquakes in the 1990s, like the 1995 Antofagasta earthquake. These earthquakes could have disturbed the underground magma chambers or created new cracks. As of 2009, the flow of magma into this area has been steady.
This rising land system is one of the largest on Earth. It is similar in size to famous calderas like Long Valley and Yellowstone. There are several older volcanoes around this uplift region. They might be fed by a flat body of magma called a sill. Special measurements of electrical signals in the Earth (called Magnetotelluric data) show a zone where electricity flows easily. This zone rises from the Earth's deep mantle into the crust. This could be the path for magma supplying the Lazufre area.
Research from 2016 suggests that this uplift has been happening for at least 400,000 years. This is based on how old lava flows and volcanoes in the area have been pushed up. Scientists believe that even a small amount of extra pressure from the magma chamber could cause the ground above it to break, leading to an eruption.
More to Explore
- List of volcanoes in Chile
- List of volcanoes in Argentina
- Los Colorados (caldera)
