Northstone (NI) Ltd Quarry and Asphalt division welcomed the Belfast Geologists’ Society to two of their quarries where Angus Kennedy (Deputy Quality Manager) and Gavin Ramsey (Environmental Officer) guided the tour.

Croaghan Quarry

The society valued their tour of the asphalt plant at Croaghan Quarry and was encouraged to learn more about recycling materials for roads.  The rock quarried at Croaghan is olivine basalt of the Tertiary Antrim Lava Group.  Minor faults run through the quarry area.   The floor of the quarry is composed of volcanic agglomerate, as can be seen in section at the new lagoon. It has been weathered to form a bright red laterite which is rich in iron and aluminium oxides and clay (kaolin).

Carmean Quarry

Limestone (chalk) is quarried at Carmean and crushed and ground to produce a variety of products for the building and animal feed industries. The Carmean quarry itself is worked out with the western part restored to pasture.  Northstone now extracts from the adjacent Glover's pit which is on the up-thrust side of the Carmean fault which separates the two pits.  The fault and the relationship between the basalt, chalk and sandstone are well displayed.

Read more about Belfast Geologists’ Societies grand day out.