Recent studies indicate that Cebu developed over an oceanic crust, vestiges of which may be seen in the island as part of the basement complexes, i.e. the Cansi Volcanics, the Tunlob Schist, the serpentinite diapirs. and perhaps even the Pandan Formation.

The serpentinite diapirs in Cebu, occurring along major fault systems spread over patches of a few to a hundred or more hectares, are interpreted as products of cold intrusion during wrench tectonics. Associated with some diapirs here are layered mafic sequences some of which exhibit tight folding and chevron structures.

The Tunlob Schist is described as consisting of chloritic orthoschist and micaceous paraschist belonging to the albite-epidote-amphibolite facies. The westernmost body is pinpointed as being originally igneous. Marked foliation characterizes the rock in the northern highlands. There is a strong possibility that some of these foliated sequences could be mafic cumulates.

Cansi Volcanics are in turn portrayed as predominantly basic lava flows locally exhibiting pillow structures. There are some reference to dike phases being present and these exhibit typical diabasic fabric. Inferences can be drawn that what is described is the upper portion of an ophiolitic assemblage.

In published descriptions of Pandan Formation, there are portions that include the association of a pillow basalt flow sequence overlain by thin bedded cherts. Regional disposition has always placed the Pandan intimately with the Cansi and the Tunlob.

The possibility therefore exists strong/y that incorporated in the mapped basement units of Cebu are rocks of ophiolitic affinity. The basalt and andesite pile stacked up by Cansi Formation volcanism apparent/y began to pour over oceanic crust that may have previously been emplaced perhaps during the Early Cretaceous. Paleogeographic reconstruction for the Mesozoic may place this oceanic crust to be continuous with, but older than, the oceanic crust
represented by the Angat Ophiolite and the ophiolitic Mt. Manapao Basalt of Masbale.