Abstract A major stratigraphical problem in the offshore Paleozoic of the Inner Moray Firth is the identification of the top of the Devonian Old Red Sandstone Group beneath the lithologically similar Permian Rotliegend Group. Wireline log criteria for a revised Old Red Group to Permian boundary are given for the Inner Moray Firth. Section lines drawn using these criteria and flattened on the overlying Triassic Smith Bank or Permian Kupferschiefer formations show a relatively thin development of Rotliegend with two depocentres. The underlying Devonian when flattened on the Eday Marl shows a systematic subcrop pattern. There is currently no exposed onshore Old Red to Rotliegend boundary, but the possibility remains that a Permian section is present in the ‘Upper Old Red Sandstone’ of Tarbat in Easter Ross. An exposed Permian–Devonian boundary is present in East Greenland and provides an analogue for the Inner Moray Firth.

Abstract The distribution of sand dunes over the southern half of Arabia conforms to the influence of two wind systems: the northern Shamal, which is a strong wind that blows to the SSE down the Persian (Arabian) Gulf and then swings to the SW across the hyperarid Rub al Khali towards North Yemen; and the strong winds of the SW Monsoon system, which were responsible for forming linear dunes that trend north-south in the Wahiba Sands of eastern Oman and SW-NE in the Thar Desert (NW India). In the Thar Desert, the SW Monsoon alternates with the weaker NE Monsoon. The dating of exposures of older dune systems by isotopic, radiometric and optically stimulated luminescence (OSL) analyses has shown that the Shamal was active throughout the latter part of the Quaternary period, and probably as long ago as Mid-Miocene time ( c. 15 Ma). At times of glacial maxima, when global sea level was some 100-120 m or more lower than now, siliciclastic and carbonate grains were deflated from the exposed surface of the Persian Gulf and transported into the NE Rub al Khali within the United Arab Emirates. It is suspected that occasionally the Shamal also transported some quartz sands from the NW onto the exposed narrow continental shelf of SE Arabia, with silt-size particles being carried into the Arabian Sea. The SW Monsoon, on the other hand, was re-established over the coast of SE Arabia several millennia after the last glacial maximum and was fully established near the coast of SE Arabia during the early Holocene interglacial after the atmospheric high-pressure system associated with the glacial period had become weaker. Early during the Holocene interglacial periods when the SW Monsoon dominated, a combination of quartz and carbonate sands was deflated from the exposed continental shelf and transported to the north into the Wahiba Sands. Aeolian activity in the Thar Desert also peaked during this period of transition from full glacial to interglacial conditions. The dune systems of SE Arabia overlie the distal edges of older alluvial fans that in Oman date back at least 350 ka. The sediments of some of these fluvial sequences in Oman reached the Arabian Sea via Wadi Batha, only to be removed by along-shore currents driven by the SW Monsoon. In the Thar Desert, the supply of aeolian sediment is mostly from fluvial sources. Marine sediments from the Arabian Sea between Arabia and Thar record the contrasting effects of the Shamal and the SW Monsoon: the former mostly as a source of wind-blown dust from Arabia and the latter by causing upwelling of nutrient-rich waters leading to organic blooms.

Abstract Permian and Triassic rocks are widely distributed beneath the seas surrounding Scotland but have only limited, mostly basin-margin, exposures on land ( Fig. 10.1 ). They occur on the coast of the Moray Firth near Elgin and Golspie, in several small basins in the south and southwest of Scotland, including Dumfriesshire, Ayrshire and the Isle of Arran, and in a series of small exposures along the western seaboard of Scotland from Kintyre, through Mull and Ardnamurchan, Skye and Raasay to the vicinity of Stornoway on the Isle of Lewis. Each of these areas will be described in the context of the adjacent, mostly offshore, basinal development. The widespread distribution of rocks of Permo-Triassic age is indicative of a former very extensive cover. The historical reasons for the offshore extent but limited onshore exposure of the Permo-Triassic sequences are outlined below. Global sea level during the Permian and Triassic was generally fairly low (Vail et al . 1977), and Scotland was located far from the coast within the former Laurussian part of the megacontinent Pangaea ( Fig. 10.2 ), thus onshore exposures of Permian and Triassic rocks are almost entirely the product of terrestrial sedimentation. Over parts of continental Europe, such conditions of deposition commenced during the Late Carboniferous. Several (4-6) Late Permian (Zechstein) marine transgressions, with intervening evaporation almost to dryness, affected the North Sea area. No route can be found for marine flooding of the time equivalent Bakevellia Sea of the Irish Sea and Antrim (Smith & Taylor 1992; Jackson