The igneous rocks of the Troodos massif have been interpreted as an uplifted segment of Cretaceous ocean crust, formed at a spreading ridge. If so, the sediments overlying them should be similar to those forming at ocean ridges and to Tertiary basal sediments found by JOIDES drilling. Directly above the Troodos pillow lavas are iron- and manganese-rich mudstones ("umbers") that are closely comparable to the iron-rich sediments associated with the latest stages of volcanism on present ridges. They are enriched in trace elements, including copper, molybdenum, lead, zinc, and vanadium. These mudstones pass upward into Campanian radiolarites and radiolarian mudstones with a diverse and well-preserved siliceous microfauna. Silica diagenesis can be compared with that of deep-se cherts. In the simpler sequences, the radiolarian rocks are overlain by Maestrichtian chalks.

In some areas, illite-montmorillonite clays above the radiolarian mudstones include major developments of melange, with transported blocks of diverse Mesozoic sedimentary and igneous rocks. These include quartz sandstones of continental derivation. Chalks also overlie the melange. The umbers, radiolarites, and chalks are interpreted readily as oceanic sediments, and the presence of the melange implies proximity of a continental margin.

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