Lias

Lias - Greyish rock which splits easily into slabs.
Light - Glazing; component part of window, divided by mullions and transoms.
Lintel - Horizontal stone or beam bridging an opening.

A rich tawny brown ferruginous limestone of the middle lias, green, mauve, and greyish-blue tints also occur. The quarry at Hornton in Oxfordshire is now closed but another outcrop occurs at Edge Hill in Warwickshire.

Lias: Greyish rock which splits easily into slabs. Lierne: A minor rib in a complex rib vault. Liernes do not spring from the main springers. Other types of ribs: diagonal, ridge, tierceron, transverse.

See also: Lancet, Gallery, Lintel, Chancel, Church