The long ridgeline in view is Fourche Mountain
and the Ouachita River Valley spreads out below. Highway 71/270
is visible as it makes its way from the community of Acorn to Y-City.
To the right of the pullout Earthquake Ridge begins.
Earthquake Ridge is about 5 acres of sandstone outcrops along the
Talimena scenic drive. Large boulders form small bluffs and cliffs
up to 20 feet in height. This naturally broken (fractured) formation
has many openings that are wide and deep enough to walk through.
It is easy to see how a person could conclude that such a feature
could have been the result of a cataclysmic event such as an earthquake.
While the earthquake lore is an exciting explanation of how this
rocky feature came into existence, it is incorrect. The ridge is
a quiet testament to the subtle yet equally effective forces of
gravity and erosion. This outcrop of sandstone is a small piece
of the massive sandstone unit called the Jackform sandstone formation.
Part of a large fold in the earth created when the Ouachita Mountains
were being formed, this sandstone layer rests on top of shale layers.
These underlying shale layers are not strong enough to hold the
sandstone layer together. As the mountains erode away, the sandstone
boulders you see are slowly fracturing and pulling apart.
