Ilgachuz Range facts for kids
Quick facts for kids Ilgachuz Range |
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Satellite image of the Ilgachuz Range
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| Highest point | |
| Peak | Far Mountain |
| Elevation | 2,410 m (7,910 ft) |
| Geography | |
| Country | Canada |
| Range coordinates | 52°46′N 125°18′W / 52.767°N 125.300°W |
| Parent range | Chilcotin Plateau |
| Geology | |
| Formed by | Shield volcano |
| Orogeny | Anahim hotspot volcanism |
| Age of rock | 6.1 to 4.0 million years |
The Ilgachuz Range is an extinct shield volcano located in British Columbia, Canada. It's not a typical mountain range formed by folding earth. Instead, it was created as a single, massive volcano. Over the past 5 million years, erosion has slowly shaped it into the range we see today.
This unique landform sits on the Chilcotin Plateau. It is about 350 kilometres (220 mi) north-northwest of Vancouver. It is also 30 km north of Anahim Lake. The highest point in the range is Far Mountain. The Ilgachuz Range is home to a special grassland ecosystem. You won't find this type of grassland anywhere else in central and southern British Columbia. The weather here is cool and dry, which is common for higher areas of the Interior Plateau.
The West Road River starts in the Ilgachuz Range. This river is 280 kilometres (174 mi) long. It flows east until it meets the Fraser River. This meeting point is between Prince George and Quesnel. The river drains a large area of about 12,000 km2. It drops over 900 meters in height before joining the Fraser River.
Contents
How the Ilgachuz Range Formed
Volcanic Beginnings
The Ilgachuz Range started erupting about 6.1 million years ago. It grew steadily over time. Like other volcanoes in the Anahim area, the Ilgachuz Range was formed by the Anahim hotspot. A hotspot is a place where hot magma rises from deep inside the Earth's mantle.
The Anahim hotspot stays in one spot. However, the North American Plate (the large piece of Earth's crust it sits on) slowly moves over it. This movement is about 2 to 3.3 centimeters each year. As the plate moves, the rising magma creates new volcanoes. Each volcano erupts for a few million years. Then, the plate's movement carries it away from the hotspot.
When a hotspot is under continental crust, the magma can get trapped. This heats the crust, causing it to melt and form a different type of rock called rhyolite. Rhyolite eruptions can be very powerful. This is because they contain a lot of gas and crystals.
The Anahim hotspot has been active for at least 13 million years. The chain of volcanoes it created, called the Anahim Volcanic Belt, stretches almost 600 kilometres (400 mi). More recently, the hotspot formed the Itcha Range and Nazko Cone. The Nazko Cone is the youngest volcano in this belt. The Ilgachuz Range is the largest single volcano formed by this hotspot. However, the Rainbow Range is the largest overall volcano in the Anahim Volcanic Belt.
First Peoples and Their History
The first people to climb the Ilgachuz Range were the South Carrier and Chilcotin tribes. They have lived in this area for hundreds of years. They would travel to hunt animals like beaver, caribou, and moose. They also gathered plants and roots. Fishing camps were set up in the area too.
The Ilgachuz Range was a very important source of obsidian for these tribes. Obsidian is a type of natural glass. It was highly valued because it could be used to make very sharp arrowheads and cutting knives. Obsidian breaks in a special way, creating edges as sharp as a razor. It was also used to make jewelry. Obsidian from Anahim was traded far and wide. It reached other parts of British Columbia and even the Coast, like Bella Coola. Red ochre, used for paint and decoration, was also found in this region.
Structure of the Volcano
The Ilgachuz Range is the second largest shield volcano in the Anahim Volcanic Belt. Other nearby ranges in this belt include the Rainbow Range and Itcha Range. The Ilgachuz Range stands at 2,410 metres (7,907 ft) above sea level. It is a bit shorter than its neighbor, the Rainbow Range. It measures about 25 km (16 mi) across.
The Ilgachuz Range was formed by two different periods of volcanic activity. First, there were eruptions of rhyolite. Later, there were flows of basaltic lava. When the volcano's magma chamber emptied, parts of the volcano collapsed. This created one or more large bowl-shaped hollows called calderas.
The volcano's structure can be thought of in different parts. These include older layers, dome-shaped formations, areas inside the caldera, and the main shield-forming layers. For example, some parts show layers of pyroclastic rocks, which are made of volcanic ash and fragments. These rocks come in many colors like green, grey, yellow, red, and white. Other parts include domes of rhyolite, which is a light-colored volcanic rock. These domes can have shiny obsidian within them.
The main shield-forming part of the volcano is made of basalt and other lava flows. These flows came from cracks in the ground, mostly around the edges of the calderas. Red cinder deposits, which are small pieces of volcanic rock, are also found here.
Itcha Ilgachuz Provincial Park
The Itcha Ilgachuz Provincial Park surrounds and includes the Ilgachuz Range. This park covers 112,000 hectares. It has a unique landscape in the West Chilcotin Uplands. The Rainbow Range is partly located in the Tweedsmuir South Provincial Park.
Itcha Ilgachuz Provincial Park features volcanic landforms and high-altitude environments. It also has forests with many wetlands. This park is very remote and has no roads. The closest towns are Anahim Lake, Alexis Creek, Nimpo Lake, Redstone, and Nazko. The nearest large town is Quesnel, which is about 200 km east of the park.
Peaks of the Ilgachuz Range
Here are some of the peaks found within the Ilgachuz Range:
- Calliope Mountain
- Camlick Mountain
- Campanula Peak
- Cindercone Peak
- Crepis Peak
- Far Mountain
- Go-around Mountain
- Hump Mountain
- Mizzen Mountain
- Mount Scot
- Phacelia Peak
- Pipe Organ Mountain
- Saxifraga Mountain
- Tundra Mountain
See also
In Spanish: Cordillera Ilgachuz para niños
