A regional strain study of Snowdonia, North Wales, has used clast orientation data from Caradoc volcanic rocks. The data, analysed using the Rf/Φ technique, have revealed that while the local strain pattern is very heterogeneous in intensity and style, it can be processed to define a regional 'average' strain. This regional strain closely approximates to plane-strain in both rigid and ductile markers. This, when considered with the style of folds, leads to the tentative suggestion that the deformation mechanism in Snowdonia is one of gently inclined and ductile simple shear from the northwest.
Seismic facies, provenance and marine faunal associations of a nearshore prograding sediment wedge offshore eastern Scotland are studied to investigate environmental changes in the adjacent North Sea during Lateglacial–Holocene time. The sediments form part of the St. Andrews Bay Member (Forth Formation), which is divided into four lithozones (L1–L4) that represent distinct pulses of sedimentation during the sequential growth of the sediment wedge. Radiocarbon dates, combined with the local curve of relative sea level change, indicate that progradation was initiated as a fluvio‐deltaic deposit (L1) during the Younger Dryas Stadial. Further construction of the sediment package took place during the mid‐ to late Holocene by sublittoral tidal processes that deposited three discrete, highstand shoreface wedges (L2–L4), which display both progradation and longshore migration (to the NE), and may have experienced episodic brackish marine conditions. A depositional cyclicity of about 1000 years is proposed for lithozones L2–L4, separated by hiatuses of 1000–2000 years. We tentatively suggest that the Holocene development of the prograding wedge offshore eastern Scotland was a response to phases of strong westerly winds driving an enhanced influx of Atlantic Water into the North Sea. A concomitant increase in rainfall may account for the freshening of the coastal zone at this time. However, correlation with the recently postulated global periods of Holocene rapid climate change remains unclear.
The faunas recorded from the Chalk of the Ipswich sheet are predominantly of BGS19 foraminifera zone (pilula to very basal quadrata macrofaunal Zone). A few samples contained longer ranging taxa which prevented accurate age determinations, although all fell within the socialis to basal quadrata zones. The occurrence of Pullenia cf. quaternaria appears to be outside its stratigraphical limits compared to southern England, but careful examination of this foraminifer indicates that it is a new species and that interpretation of some other records in eastern England may deserve reconsideration.
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