Minnis ASSI

Minnis has been declared as an ASSI because of its important earth science features.

Minnis contains perhaps the best example of an active mudflow in Northern Ireland and a huge variety of fossils have been found there.

The mudflow exists because of the geology in the area. Palaeogene age basalt and Cretaceous age limestone form low cliffs at the site. These harder rocks overlie softer Cretaceous sandstone and Jurassic age mudstone and limestone.

The mudstone can absorb a lot of water and over time the rock turns back into loose mud and flows. Occasionally, the road is closed by one of these mudflows.

For that reason, loose mud at the bottom of the slope is regularly tipped onto the shore, where the action of waves and water wash the mud away, leaving behind fossils.

Among the fossils found at the site are the shells of snails, bivalves, ammonites & belemnites (ancient shellfish related to squid), along with corals, fish, sea urchins and even bones from an ancient sea reptile - an Ichthyosaur - known as the ‘Minnis Monster’.