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The Culzean Field, located in UK CNS Block 22/25a between the Lomond Deep and the Heron Cluster, was discovered in 2008 by the 22/25a-9Z well and subsequently appraised by wells 22/25a-10, 22/25a-10Z, 22/25a-10Y and 22/25a-11. The primary reservoir is the Triassic Skagerrak Formation, with a secondary reservoir in the Middle Jurassic Pentland Formation. Total recoverable reserves are estimated to be 250 – 300 MMBOE. One principal challenge concerning the Skagerrak reservoir in Culzean is the stratigraphy, and especially how it relates to adjacent wells in Quadrant 22. Historically, biostratigraphic age determinations of the Skagerrak Formation in Quadrant 22 have been unsuccessful, unlike in Quadrant 30 where biostratigraphic recovery is good and ages are well established. However, good recovery in the Culzean discovery well 22/25a-9Z enabled identification of the Jonathan Mudstone Member, the Joanne Sandstone Member, the Julius Mudstone Member, the Judy Sandstone Member and Marnock Mudstone. The Joanne Sandstone Member and the Jonathan Mudstone Member are therefore more widely distributed in Quadrant 22 than has been hitherto recognized. The Skagerrak Formation in Culzean also has a well-defined heavy mineral stratigraphy, enabling correlation into the adjacent Marnock, Skua, Egret and Heron fields. This correlation shows that the reservoir succession in Egret and Heron is largely equivalent to the Joanne Sandstone Member, whereas Marnock and Skua contain the Judy Sandstone Member overlain by truncated Joanne Sandstone Member and Julius Mudstone Member intervals.

The Ionian zone is a classic thinskinned linear fold and thrust belt forming a part of the external Hellenides, in westernmost Greece. The region has been a focus of intensive paleomagnetic investigation since the early 1980s, and it is now generally believed to have undergone a multiphase clockwise vertical-axis rotation of 40°-60°since the Miocene, although the timings are disputed, and spatial variations within this trend have been largely ignored thus far. We present data from thirty new paleomagnetic sites and a reappraisal of previous results from the Ionian zone in an attempt to construct a unified model for the tectonic evolution of the Ionian zone. We find that the clockwise rotations may be due, at least partially, to rotation during thrust sheet emplacement, with evidence of a forelandward decrease in rotation. However, superimposed on this pattern of thinskinned rotations we observe post-Pliocene rotations that affect multiple thrust sheets in a consistent manner. These are interpreted to result from regional tectonics associated with, for example, the Kefallonia fault zone at the western termination of the Hellenic arc and from deformation in the transition zone between Anatolian westward extrusion and southern Aegean extension. Overall, the result is a pattern of thinskinned , westward-decreasing clockwise rotations distorted by superimposed thickskinned rotations resulting from the complex interplay of plate motions in the eastern Mediterranean.

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