Day 5, Locality 3

3) Petra tou Romiou; tourist stop and localities.

Taking the pedestrian underpass from the souvenir shop and cafe to the beach, Petra tou Romiou can be examined.  The most evocative feature of this large limestone block is the highly polished western face striated with slickensides, which demonstrate that blocks such as this were once jostled around in a tectonic melange.  Within the limestone are small volcanic clasts and a chilled pillow fragment, which have compositions of trachyandesite and trachyte.  Along the coast to the west are further outcrops of pillow lava, lime­stone and red deepwater sedimentary rocks.  Faulted into these Upper Triassic rocks and exposed in the cliffs, are rocks, mainly serpentinite, of the Troodos ophiolite.

The main ‘rock’ is a lump of Petra tou Romiou limestone, an oceanic platform carbonate of the Mamonia Dhiarizos Group. It is not in situ, nor is it a landslipped mass. This is an olistolith of the Moni Formation, the surrounding matrix having been removed by erosion.

Close by, on the beach under the roadway, is an exposure of pillow lavas. These too are part of the olistolith. These blocks represent part of the Moni melange, with an intra-Maastrichtian age. The melange is of tectonic origin, and a large surface of Aphrodite’s rock with slickensides attests to this. The melange was formed during the tectonic activity related to the rotation of the Troodos microplate, and the slicing and juxtaposing of the Mamonia Terrane alongside the Troodos basement, which was taking place in the Maastrichtian ( MacLeod, 1990; Swarbrick, 1993).

Climbing the slope to the road, the low cliffs opposite show gently dipping, well bedded radiolarites. These are in-situ Mamonia Terrane rocks of Late Triassic (?) age deposited at bathylal depths in part of the Neotethyan ocean basin.  They represent the sedimentary cover over earlier ocean floor pillow lavas.  Although these lithologies are in-situ, ie not redeposited olistrostromes, they are nonetheless allochthonous, and part of the tectonically emplaced terrane unit incorporated within the Troodos microplate during its rotation.