The Polis graben system in west Cyprus consists of two neotectonic extensional basins. The Polis graben is of Late Miocene age, bounded to both sides by major NNW-SSE trending normal faults. Around 7% extension occurred perpendicular to the fault trend. The Pegia half-graben, to the west of the Polis graben, is of latest Pliocene to earliest Pleistocene age and is bounded by WNW-ESE striking normal faults. Approximately 10% extension occurred perpendicular to these faults. In both graben normal faults are seen on three scales; extensional joints are also common. Faults of all scales bound generally internally undeformed fault blocks which are tilted perpendicular to the graben trend, normally back-rotated on synthetic faults and forward rotated on antithetic faults. In the Polis graben, transfer zones accommodate changes in the structural style and timing of faults along the length of the graben. The location of faults within the Polis graben system may be partly controlled by the underlying basement structure. Extensional structures in the Polis gaben are comparable with extensional features in other basins. The sedimentary sequence in west Cyprus reflects the structural development of the two extensional basins. Early to mid-Miocene pre-rift, Late Miocene syn-rift and Pliocene post-rift sequences are recognized in the Polis graben. The first depositional features related to neotectonic structures are seen at the Oligo-Miocene boundary. Erosion of the Palaeogene Lefkara Formation on the margins of the area was followed by deposition of Lower Miocene reef limestones (the Terra Member), whilst basinal chalk deposition (the Miocene Pakhna Formation) continued in the centre of the area. This is thought to reflect relative uplift of west Cyprus and development of a broad basin in the Early Miocene. Hemipelagic carbonates of the Pakhna Formation were deposited throughout the basin by mid-Miocene times. In the Late Miocene, shallowing of the basin occurred and early syn-rift reef limestones of the Koronia Member accumulated on the flanks of a narrow basin. Rapid eustatic fall in the Messinian led to emergence and erosion of the northern part of the graben, and of the area of the Pegia half-graben. The southern basin was the site of syn-rift evaporite deposition (the Kalavasos Formation). In the north, conglomerates and breccias derived from active fault scarps were locally deposited.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:660470 |
| Date | January 1995 |
| Creators | Payne, Anne Sheila |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/15605 |
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