Elephant Canyon Formation
The gray, fossil-rich marine formation at the head of Cataract Canyon — a Pennsylvanian–Permian boundary-spanning unit whose name is contested ('lower Cutler beds').
Also known as: Elephant Canyon
Paleozoic — ancient sea life, from the first shells to the first forests
The world back then
Around the Pennsylvanian–Permian boundary, about 295 million years ago. You're standing in a shallow, cyclic sea at the edge of the Paradox basin, the water advancing and retreating over a muddy shelf beside a rising highland. Rice-grain fossils and shells carpet the gray bottom. Warm, shallow, and repetitive — the sea can't decide whether to stay.
Now it's the gray rock low in Cataract, and you drift right over it with the big whitewater still downstream. That indecisive old sea settled into stone so you could pass it in comfort. Being the warm animal who arrives after all the flooding and just enjoys the ride — hard to beat.
Recognize it in the field
- Typical color
- gray
- Weathers as
- Ledge-and-slope marine interbeds low in the inner gorge.
Look for
- cyclic marine limestone/sandstone interbeds
- fusulinid-bearing (biostratigraphically datable)
- sits directly on the Honaker Trail Formation
- upper part interfingers with the Cedar Mesa Sandstone
How this rock was made
Cyclic marine incursions across the Paradox basin, marginal to the emergent Uncompahgre highland and the early Cutler clastic wedge.
The setting: shallow-marine shelf
Definition-unstable: Loope et al. (1990) placed the lower ~450 ft (Virgilian) in the formation and reassigned the upper ~590+ ft to the informal 'lower Cutler beds'; the original type Elephant Canyon is ~1,000+ ft. Figures are approximate.
In the rock record
Part of the Cutler Group.
↑ Younger — rests above
↓ Older — sits beneath
Where to see it
Regions: Colorado Plateau (Paradox Basin)
- type section at Elephant Canyon, near the Green–Colorado confluence (head of Cataract Canyon)
- Needles / Maze margins, inner gorge
Float past it: Cataract Canyon · Narrow Canyon