Misema Caldera facts for kids
Quick facts for kids Misema Caldera |
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Map of the Blake River Megacaldera Complex. Misema Caldera is highlighted in red.
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| Location | Ontario-Quebec, Canada |
| Range | Canadian Shield |
| Geology | Calderas |
| Age | 2,704-2,707 MYA |
| Volcanic arc/belt | Blake River Megacaldera Complex |
The Misema Caldera is a very old and huge caldera located in Ontario and Quebec, Canada. It formed about 2,704 to 2,707 million years ago. A caldera is a large, bowl-shaped hollow that forms when the ground collapses after a volcanic eruption.
Where is the Misema Caldera?
The Misema Caldera is a key part of an even bigger volcanic area called the Blake River Megacaldera Complex. Think of it as the main part of a giant ancient volcanic system. It's truly massive, stretching between 40 and 80 kilometres (about 25 to 50 miles) across!
What is the Misema Caldera Made Of?
The Misema Caldera was created from at least two huge shield volcanoes. These volcanoes were made mostly of a type of rock called mafic rock, which is dark and rich in iron and magnesium. They formed more than 2,703 million years ago.
Around the edge of the Misema Caldera, there's a special area about 10 to 15 kilometres (6 to 9 miles) wide. This area has inner and outer rings. Here, scientists have found many mafic ring dikes. These are like walls of hardened magma that formed in a circular shape. They also found pyroclastic sediments, which are bits of volcanic rock and ash that settled underwater.
These ring dikes might be what's left of deeper parts of the volcanoes that collapsed. The pyroclastic bits could have come from smaller volcanoes nearby or from the Misema Caldera itself collapsing.
The Misema Caldera is the oldest and largest caldera in the Blake River Megacaldera Complex. It's so big that it's similar in size to the famous Lake Toba caldera in Indonesia.
See also
In Spanish: Caldera de Misema para niños
