Carswell is an impact structure within the Athabasca Basin of the Canadian Shield in northern Saskatchewan, Canada. It is in diameter and the age is estimated to be 115 ± 10 million years (Lower Cretaceous). The impact structure is exposed at the surface.
thumb|left|235px|Landsat image with crater structure overlain. The central zone is the highly faulted central peak complex including the Peter River gneiss and the Earl River complex. The outer ring is a zone of faulted bedrock including the Carswell Formation and Douglas Formation. Unshaded areas are generally mapped as the William River Subgroup.
The central peak complex of faulted metamorphic rocks displays shatter cones, planar deformation features, pseudotachylyte veins, and impact melts and breccias. There is also evidence of planar deformation features in quartz grains far to the south of the outer ring of present-day hills, which suggests the ring of hills are not the rim of the original crater but a peak ring within a much larger structure. The Carswell Formation, composed of algal limestone, may have formed on seamounts elevated to near the surface as part of the peak ring. Since the mine is now closed and decommissioned, there are no travel services in the vicinity and no functional airstrip. Motorists driving to the structure need to carry sufficient fuel and supplies for the round trip back to La Loche.
See also
- List of impact structures in North America
- Geology of Saskatchewan
References
External links
- Aerial exploration of the Carswell impact structure