Geology

 

Did You Know?

The Black Canyon is one of the fundamental resources and values identified in the park's foundation document. The exposed rock walls are windows to deep earth processes revealing evidence of extreme heat and pressure, magma intrusions, and continental movement. Resistant to erosion, the gorge has weathered into distinct and diverse stretches.

 

Rock pillars in Black Canyon

NPS

Deep, Steep, and Narrow

About 60 million years ago, a small area of land uplifted and brought 1.8 billion year old metamorphic rock to high elevations. This is called the Gunnison Uplift. About 30 million years ago, large volcanoes erupted on either side of this uplift, burying it in volcanic rock. Then, as early as two million years ago, the Gunnison River began flowing in force. The river and time eroded all of the volcanic rock and cut a deep canyon in the metamorphic rock below.

What you see today is a deep, steep, and narrow canyon: the Black Canyon of the Gunnison.

 

Black Canyon's Geology Facts

Black Canyon is the result of multiple episodes of uplift and erosion and the carving power of the Gunnison River.

• The canyon displays a wide variety of rock types - including igneous, metamorphic, and sedimentary.

• Black Canyon exposes nearly two billion year old Precambrian "basement rocks," one of the best examples in the world.

• Deposition, uplift, and erosion are the key factors that created the canyon seen today.

• Black Canyon has paleontological resources such as Jurassic and Cretaceous fossil plants, invertebrates, vertebrates (fragmentary) and trace fossils.

• Black Canyon's greatest depth is 2,722 feet (829 m), just north of Warner Point.

• The narrowest width is 40 feet (12 m) at the river.

• The total length of the canyon is 48 miles (77 km), with 14 miles (22.5 km) within the national park boundary.

• Average descent over the entire length of canyon is 43 feet/ mile (8 m/ km).

 

Canyon Formation

Learn about Black Canyon on the geologic time scale. Its formation has been a process for millions of years and continues today.

 

 

Canyon Characteristics

Black Canyon is made up of rocks from the Precambrian, Mesozoic, and Cenozoic eras. It is not the steepest, deepest, or narrowest canyon in the west - but it is an impressive example of all three combined.

 

 

Black Canyon of The Gunnison National Park lies on the far eastern edge of the Colorado Plateaus Physiographic Province.

NPS/Geologic Resources Division

Edge of the Colorado Plateau

Black Canyon of the Gunnison lies on the eastern edge of the Colorado Plateau - a region spanning Arizona, Colorado, New Mexico, and Utah. This physiographic province highlights a region well known for its natural features, plateaus, buttes, deep canyons, and colorful rock layers.

It is also adjacent to the Southern Rocky Mountains, a province known for massive mountains and valleys in between.

The park shares geologic history and other characteristics from physiographic provinces in the region.