Hibernian Greensands Group

The name is derived from the characteristically coloured marls and sandstones which occur beneath the chalk particularly along the Antrim coast.

The strata are exposed on or near to both the northern and eastern coasts of Antrim and also between Portrush and Dungiven within County Londonderry.

Further outcrops occur between Belfast and Lurgan and between Dungannon and Magherafelt.

It unconformably overlies a variety of units from the Metamorphic Precambrian Southern Highland Group to the Lower Jurassic Lias.

Various units were earlier referred to as glauconitic or chloritic marls.