We present new interpretations of Digital Elevation Model (DEM) data and marine fossils collected from three sites on the Rhins of Galloway which, contrary to recent proposals, suggest that the landforms and deposits of the region do not represent evidence for a readvance during the Lateglacial Period. Rather we suggest that the high-arctic fauna found in the region are representative of an earlier, colder part of a Middle Devensian ice-free interval. The predominantly streamlined topography, and distinct lack of identifiable discrete moraine limits argues for only minor, local glacial advances, in combination with widespread rapid retreat across the peninsula at the end of the Lateglacial
Geological notes and local details for 1:10 000 sheet TM 35 SE (Snape) : part of 1:50 000 sheets 190 (Eye) and 208 (Woodbridge)
This report describes the geology of the 1:10 000 sheet TM 35 NE which is included in the Eye (190) and Woodbridge (208) geological maps. The area was f i r s t surveyed by W Whitaker and W H Dalton as part of the Old Series One-Inch sheet 50 SE published in 1883. The primary six-inch survey of the Snape area was made by J A Zalasiewicz in 1982-3 under the direction of D r W A Read as Programme Manager. Uncoloured dyeline copies of the map can be obtained from the British Geological Survey, Keyworth. The sheet area lies some 10 Km north-east of Woodbridge, Suffolk. Most of the ground is broadly f l a t and lies a t c 20-25 m OD. It is underlain largely by Boulder Clay and given over to arable farming. Boulder Clay is absent from the south-east of the area, where a broad outcrop of Kesgrave Sands and Gravels largely coincides with coniferous forest. The south-eastwards flowing River Alde and its tributaries have incised wide valleys in the central and northern parts of the area. Kesgrave Sands and Gravels and the underlying Chillesford Sand crop out in the valley sides, together with irregular masses of Fluvio-Glacial Sand and Gravel and Boulder Clay. The wide f l a t valley floors are underlain by freshwater and estuarine alluvium, and are given over to arable farming with some pasture. The major settlement is Snape, where The Maltings is now a well-known concert hall. There are two smaller settlements, Tunstall and Blaxhall, and a number of scattered farmsteads
Rapidly changing geomagnetic field variations constitute a natural hazard, for example in navigation and, through geomagnetically induced currents, to power grids and pipeline networks. To understand this hazard we have continuous magnetic measurements across the world for typically less than 100 years. Much of the older data is also in analogue form, or is only available digitally as hourly or daily magnetic indices or mean levels. So it may not yet be clear what the true extremes in geomagnetic variations are, particularly on time scales - seconds to minutes - that are relevant for estimating the hazard to technological systems. We therefore use a number of decades of one minute samples of magnetic data from observatories across Europe, together with the technique of 'extreme value statistics’ to explore estimated maxima in field variations in the horizontal strength and in the declination of the field. These maxima are expressed in terms of the variations that might be observed once every 100 and 200 years. We also examine the extremes in one-minute rates of change of these field components over similar time scales. The results should find application in both hazard assessment for technologies and in navigation applications. The results can also be used to more rigorously answer the often-asked question: “just how large can geomagnetic storms and field variations be?
The roddons of the English Fenlands are fossilised silt and sand-filled tidal creek systems of mid- to late-Holocene age, incised into contemporaneous clay deposits. However, anthropogenic change (drainage and agriculture) has caused the former channels to become positive topographical features. Three stratigraphically discrete generations of roddon have been discriminated. They all show well-developed dendritic meander patterns, but there is little or no evidence of sand/silt infill during meandering; thus, unlike modern tidal creeks and rivers they typically lack laterally stacked point bar deposits, suggesting rapid infill. Major “trunk” roddons are rich in fine sands and there is little change in grain size from roddon mouth to the upper reaches, suggesting highly effective sand transport mechanisms and uniform conditions of deposition. Tributaries are silt-rich, while minor tributaries also have a significant clay component. During infill, active drainage networks appear to have been choked by sediment, converting mudflat/salt-marsh environments into widespread peat-forming freshwater reed swamps
We review the scientific literature, especially from the past decade, on the impacts of human activities on the Antarctic environment. A range of impacts has been identified at a variety of spatial and temporal scales. Chemical contamination and sewage disposal on the continent have been found to be long-lived. Contemporary sewage management practices at many coastal stations are insufficient to prevent local contamination but no introduction of non-indigenous organisms through this route has yet been demonstrated. Human activities, particularly construction and transport, have led to disturbances of flora and fauna. A small number of non-indigenous plant and animal species has become established, mostly on the northern Antarctic Peninsula and southern archipelagos of the Scotia Arc. There is little indication of recovery of overexploited fish stocks, and ramifications of fishing activity oil bycatch species and the ecosystem could also be far-reaching. The Antarctic Treaty System and its instruments, in particular the Convention for the Conservation of Antarctic Marine Living Resources and the Environmental Protocol, provide a framework within which management of human activities take place. In the face of the continuing expansion of human activities in Antarctica, a more effective implementation of a wide range of measures is essential, in order to ensure comprehensive protection of the Antarctic environment, including its intrinsic, wilderness and scientific values which remains a fundamental principle of the Antarctic Treaty System. These measures include effective environmental impact assessments, long-term monitoring, mitigation measures for non-indigenous species, ecosystem-based management of living resources, and increased regulation of National Antarctic Programmes and tourism activities
The zircon age spectrum in a sample from the Canonbie Bridge Sandstone Formation (Asturian) of southern Scotland contains two main peaks. One is Early Carboniferous in age (348– 318 Ma), and corresponds to the age of igneous activity during the Variscan Orogeny. The other is of late Neoproterozoic to early Cambrian age (693–523 Ma), corresponding to the Cadomian. Together, these two groups comprise 70 % of the zircon population. The presence of these two peaks shows unequivocally that a significant proportion of the sediment was derived from the Variscides of western or central Europe. The zircon population also contains a range of older Proterozoic zircons and a small Devonian component. These could have been derived from the Variscides, but it is possible that some were locally derived through recycling of northerly derived sandstones of Devonian–Carboniferous age. The zircon age data confirm previous suggestions of Variscide sourcing to the Canonbie area, made on the basis of petrographical, heavy mineral and palaeocurrent evidence, and extend the known northward distribution of Variscan-derived Westphalian sediment in the UK