The Lower Coralline Limestone (LCL) is the oldest lithological unit exposed in the Maltese Archipelago. The exposed portions of the LCL are of Late Oligocene age. The oldest part of the unit is comprised of fine grained carbonates (wackestones and mudstones) which are succeeded to coralline rich deposits with some corals. The top of the unit is composed once more of fine grained carbonates but with bryozoan and larger benthic foraminifera. The unit is capped by a phosphatic hardground.

The LCL can be encountered on the south east of Gozo as well as along the cliffs of the south east of Malta. It's best exposure is along the north eastern margins of Malta, notably near Magħtab and San Pawl tat-Tarġa where is is quarried.