The Phuket Group is the oldest rock unit in the Phuket-Takua Pa-Krabi region of the Thai Peninsula. The Group comprises two Formations: a Lower Formation of Ordovician, or possibly Cambrian, to Lower Permian age, exceeding 3 km in thickness, and an Upper Formation of early Permian age between 100 and 200m thick.

Facies analysis shows that the Lower Formation consists of mass flow deposits and sandstones comparable to the deposits of modern continental rises and continental slopes. The Upper Formation was deposited in a shallow marine and probably deltaic environment. The Phuket Group and litho-logically similar sedimentary rocks to the north and south occupy an elongate belt extending from the Shan States of Burma to the Langkawi Islands in Malaysia. The sediments, which are rich in quartz, were derived from a continental area and deposited on its margin. In contrast to previous interpretations of the Palaeozoic history of Peninsular Thailand, it is considered that the continental source lay to the east. The continental margin resembled modern margins of either Atlantic or Japan Sea type.

Two cleavages occur in the sandstones: coarse fissuring, and a fine irregular fracturing, which may form conjugate sets. Linear structures of five styles, all of which are parallel to the fold axis, are developed on the bedding due to the intersection of this element by the cleavages.

The paper represents a reassessment of the drift stratigraphy at Porth-clais. The characteristics of the various Pleistocene deposits at the site are analysed in detail, and the sequence of drifts is then examined in its regional context. While the age of the raised beach at Porth-clais is still open to doubt, it seems that the non-calcareous till was deposited during a Late Weichselian glaciation by the Irish Sea glacier. This glacier probably extended much further south in St. George's Channel than suggested by other workers, although the ice stream which crossed St. David's Peninsula may not have been very thick.

The Loch Awe Syncline (Bailey, 1913), affecting the Middle and Upper Iltay Dalradian Successions of Argyllshire, is recognised as an F1 structure. The present work shows that the west limb is arched over a pre-O.R.S., late Caledonian monoform responsible for the fan of first cleavage over the area investigated. Reflecting the style of the earlier Ben Lui-Tarbert Monoform (Roberts & Treagus, 1964), the newly described Kilmelford–Turnalt Monoform adds to the symmetry of the Iltay Nappe Complex. “Mushroom” Structure (Rast, 1963).

A continuous profile of 430 large sand waves shows a progressive decrease in height (with some increasing crest separation) in their inferred migration direction, as well as showing the changing effectiveness of the ebb and flood tidal currents to move sand. The height of these and other sand waves around the British Isles is virtually unrelated to the depth of the sea, contrary to what has been suggested elsewhere. However, most sand waves occur on the continental shelf broadly because it is there that the currents reach a suitable range of speeds and sufficient sand is available at the present time.