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This paper presents a new geological map of Kea, in the western Cyclades of Greece. The map shows the three-part tectonostratigraphy typical of many Cycladic islands: (i) Footwall of blue-grey calcitic marble mylonites and likely volcanoclastic-derived schists of the Cycladic Blueschist Unit, almost completely retrogressed to greenschist facies; (ii) Detachment zone of phyllonites, schistderived protocataclasites and foliated cataclasites, white calcitic marble ultramylonites and dolostone (ultra)-cataclasites; (iii) Hanging wall of dolostones, with a variable protocataclastic deformation, and occasional foliated calcitic marbles. In the footwall, relict blueschist facies assemblages are rare, being best preserved in gneisses and Fe-Mn-rich rocks (both uncommon lithologies). The bluegrey calcitic marble mylonites, which are generally thicker than elsewhere in the Western Cyclades are more common on the eastern side of the island. This may reflect a lateral ramp geometry between the footwall and overlying detachment-zone. Structural data indicate a consistent top-to-SW to S directed deformation, confirming that the detachment on Kea is part of the West Cycladic Detachment System. Few significant steep faults were observed on the island, although the linear coastlines and valleys suggest that many minor faults or fracture zones may be present. [ABSTRACT FROM AUTHOR]