From Centre to Circumference

This book began with one site in Ireland and closes with another. The Loughcrew Hills in County Meath include at least twenty-five megalithic tombs, located on three summits along a prominent ridge. Many of them were investigated in the nineteenth century when Neolithic artefacts were found there. More recent work has been less extensive but features an analysis of the carved decoration inside these monuments, for the Loughcrew complex is one of the main concentrations of megalithic art in Europe (Shee Twohig 1981: 205–20). Early excavation in the westernmost group of monuments had an unexpected result, for Cairn H contained a remarkable collection of artefacts which must have been deposited three thousand years after the tomb was built. They included bronze and iron rings, glass beads, and over four thousand bone flakes (Conwell 1873). A new excavation took place in 1943, but its results only added to the confusion and, perhaps for that reason, they were not published for more than six decades (Raftery 2009). They seemed to show that the artefacts, which obviously date from the Iron Age, were directly associated with the construction of the monument; today it seems more likely that they were a secondary deposit. When they were introduced to the site, the tomb may have been rebuilt. One reason why the bone flakes attracted so much attention is that a small number of them—about a hundred and fifty in all— were decorated in the same style as Iron Age metalwork. Most of the patterns are curvilinear and show the special emphasis on circles and arcs that characterize ‘Celtic’ art (Raftery 1984: 251–63). This discovery illustrates a problem in Irish archaeology. A few stone tombs in other regions were decorated in a style that has been identified as either Neolithic or Iron Age (Shee Twohig 1981: 235–6), but in the case of the flakes from Loughcrew there is no such ambiguity. Not only do the incised patterns compare closely with those on metalwork, the decorated artefacts were associated with beads and rings dating to the end of the first millennium BC. Even so, two problems remain.

The ‘Staffordshire Hoard’: the Fieldwork

The Staffordshire Hoard was found by a metal detectorist on arable land in the parish of Ogley Hay in south Staffordshire in July 2009, and was recovered by archaeologists from Staffordshire County Council and Birmingham Archaeology. More than 3,940 pieces were retrieved, mostly of gold or silver alloy and mostly representing what appear to be martial battle goods. The date of the material has yet to be ascertained but the artefacts appear to range from the late sixth to the early eighth centuries AD. The reasons for burial remain, as yet, largely unknown. The choice of location, on the north-western spur of a prominent ridge, could have been intended to facilitate its rediscovery, unless the locale held a symbolic significance within the wider landscape. The second stage of fieldwork, in March 2010, identified a number of undated field boundaries and undated palisade trenches perhaps associated with a small farmstead of pre- or post-Roman date, unlikely to be associated with the hoard.

Launde, a Terminal Palaeolithic Camp-site in the English Midlands and its North European Context

The paper describes a small late Upper Palaeolithic open-air site situated on a prominent ridge top interfluve in the English Midlands. A discrete cluster of worked flint of late Palaeolithic blade technology was discovered within an excavated area of 100 m2. The lithic scatter represents the hearth-side activities of a short-term occupancy by a small hunting group with evidence for provisioning of flint, production of blades/bladelets, and toolkit maintenance. Spatial analysis provides some dynamics to these activities. The assemblage has strong affinities with the Late Glacial–early Post-glacial Long Blade industries of southern England and northern France but displays many attributes that are atypical of the classic sites. The Launde assemblage appears to be a missing fades of the Long Blade tradition. The blade technology and the typology of the projectile points are also closely paralleled further afield in Belgium, the Netherlands and western Germany, what might be termed a late Western Ahrensburgian, probably dating to the early Pre-Boreal at the beginning of the 10th millennium BP.

Geology and origin of the Brandon Hills, southwest Manitoba

The Brandon Hills, formed during the deglaciation of southwestern Manitoba in Late Wisconsinan time, are usually mapped as end moraine, although glaciofluvial deposits are common and are responsible for some distinctive landforms. In the central and western part of the study area a series of subparallel ridges, composed of glaciofluvial deposits overlain by up to 5 m of till, are believed to have originated when sediments were deposited in a series of tunnels within or beneath the ice. Near the eastern end of the hills, a prominent ridge, 4 km long and up to 60 m high, exhibits many of the attributes of an esker. A smaller ridge on the south side of the hills is also esker-like in form.The pebble lithology of the till and of the glaciofluvial deposits is similar and is dominated by material derived from the Precambrian Shield and the Paleozoic outcrop belt to the northeast rather than from local shale bedrock. Dolomite in the till exhibits bimodal frequency distribution with the terminal grade < 0.062 mm.

Structures and Ice Deformation in the White Glacier, Axel Heiberg Island, Northwest Territories, Canada

The major structures in the long, narrow tongue of a sub-polar valley glacier are described: namely, longitudinal foliation, crevasses, clear-ice layers related to crevasses, debris-rich layers (frequently referred to as thrust or shear planes in the past), and folds. The foliation is vertical, is as well-developed in the centre of the glacier as at the margins, and does not, apparently, form perpendicular to the principal compressive strain-rate axis, nor exactly parallel to a line of maximum shearing strain-rate, although it sometimes approximately coincides with the latter. The intensity of foliation development is not related to the magnitude of the strain-rates, but the structure consistently lies parallel to flow lines through the glacier. There is no critical extending strain-rate, as such, associated with the development of new crevasses. Some crevasses have formed where the principal extending strain-rate is as low as 0.004 a-1while, in other areas, extending strain-rates of 0.163 a-1have not always resulted in fracturing. Prominent clear-ice layers, referred to as crevasse traces as displayed at the glacier surface, have formed in crevasse belts parallel to the main fracture directions. These are interpreted either as tensional veins or as the result of the freezing of water in crevasses. Extension parallel to the layering occurs during flow and, near the snout, the surface dip decreases rapidly. The fact that the crevasse traces can be followed to the snout implies that fracture occurs almost to the bottom of the glacier in the source area of the traces. Near the snout, debris-rich layers have developed parallel to the crevasse traces; frequently these are marked by prominent ridge-like ice-cored moraines. It is suggested that these structures are formed by a combination of basal freezing and thrusting. Isoclinal and tight similar folds on all scales are present. Some may be formed by the passive deformation of clear-ice layers as a result of differential flow; others may arise from the lateral compression of the original stratification in areas where ice flow becomes constricted by the narrowing of the valley. An axial plane foliation sometimes is associated with these folds.

Structures and Ice Deformation in the White Glacier, Axel Heiberg Island, Northwest Territories, Canada

The major structures in the long, narrow tongue of a sub-polar valley glacier are described: namely, longitudinal foliation, crevasses, clear-ice layers related to crevasses, debris-rich layers (frequently referred to as thrust or shear planes in the past), and folds. The foliation is vertical, is as well-developed in the centre of the glacier as at the margins, and does not, apparently, form perpendicular to the principal compressive strain-rate axis, nor exactly parallel to a line of maximum shearing strain-rate, although it sometimes approximately coincides with the latter. The intensity of foliation development is not related to the magnitude of the strain-rates, but the structure consistently lies parallel to flow lines through the glacier. There is no critical extending strain-rate, as such, associated with the development of new crevasses. Some crevasses have formed where the principal extending strain-rate is as low as 0.004 a-1while, in other areas, extending strain-rates of 0.163 a-1have not always resulted in fracturing. Prominent clear-ice layers, referred to as crevasse traces as displayed at the glacier surface, have formed in crevasse belts parallel to the main fracture directions. These are interpreted either as tensional veins or as the result of the freezing of water in crevasses. Extension parallel to the layering occurs during flow and, near the snout, the surface dip decreases rapidly. The fact that the crevasse traces can be followed to the snout implies that fracture occurs almost to the bottom of the glacier in the source area of the traces. Near the snout, debris-rich layers have developed parallel to the crevasse traces; frequently these are marked by prominent ridge-like ice-cored moraines. It is suggested that these structures are formed by a combination of basal freezing and thrusting. Isoclinal and tight similar folds on all scales are present. Some may be formed by the passive deformation of clear-ice layers as a result of differential flow; others may arise from the lateral compression of the original stratification in areas where ice flow becomes constricted by the narrowing of the valley. An axial plane foliation sometimes is associated with these folds.