Lizard complex

In the area of Ogo dour at the Northern reaches of Predannack, dunite, a highly depleted peridotite derivative which consists of almost pure olivine, is found.

The hornblende schist, found in contact with the serpentine mass directly to the North (at Ogo Dour) and to the South (at Pentreath and Church Cove) is the metamorphic remnant of basaltic intrusives into the upper crust.

The Man of War Gneiss is interpreted as a sequence of metamorphosed igneous rocks, possibly intruded as part of the break-up associated with the formation of the ocean.

U-Pb dating gives a Late Cambrian age for both the Man of War Gneiss and for intrusions cutting early fabrics in the Old Lizard Head Series[5][6] The current outcrop pattern of the various units of the Lizard Complex is mainly controlled by Carboniferous age normal faulting.

The earliest structures seen in the ophiolitic rocks are steeply-dipping foliations thought to represent deformation in lithosphere scale shear zones, associated with continental break-up in the early Devonian.

[8] It has been suggested that the Kennack Gneiss (a mixture of basic and acidic igneous rocks) was formed by partial melting during the obduction of the ophiolite onto the continental crust.