Carboniferous fossil forests

Forests of Carboniferous age, first described in detail in the nineteenth century, are often illustrated in textbooks, but their ecological and evolutionary significance has been largely overlooked or, worse, misrepresented. It has often been thought that the standing fossil forests found rooted in coals represent relicts of the peat-forming vegetation. Recent research has suggested that this is not always the case and that many of the standing trees represent an essentially non-peat-forming wetland ('clastic swamp') vegetation comprising a distinctive set of genera and species of plants. Recent investigation of several famous examples - Weaklaw, Arran and Joggins as well as new examples such as Mary Lee and Table Head - is throwing new light on the ecological and evolutionary significance of these fossil forests.     

Periglacial phenomena in the wooded areas of Northern Sweden - relicts from the Tärendö Interstadial

Frost-shattered bedrock and ventifacts interpreted to be abraded by drifting snow or ice particles occur frequently in the wooded areas of northernmost Sweden. Ice-wedge casts and periglacial involutions are encountered more sporadically. The phenomena cannot be explained by the present or the Holocene climate and demonstrably pre-date the last deglaciation. The relation to glacial and non-glacial stratigraphy, and to ice flow during the latest glacial stade, strongly suggests that the periglacial activity dates from the local Tärendö Interstadial, tentatively correlated with Odderade. The presence of the periglacial features implies not only that different morphological formations survived the erosive impact of the last continental ice sheet but also that in wide areas the very ground surface, including ventifacts in primary position, is the same today as during the interstadial. A similar situation appears to prevail in northernmost Dalecarlia and parts of Härjedalen and Jämtland in central Sweden.     

Striated Surfaces on Meteorites: Shock Fractures,Not Slickensides

Abstract Veined and brecciated chondrites commonly display striated fractures which have been interpreted as slickensides (fault dislocations). Observations on several such fractures in various collections suggest they are not true slickensides but, instead, are probably shock features related to shatter coning.     

Flow patterns, sedimentation and deposit architecture under a hydraulic jump on a non-eroding bed: defining hydraulic-jump unit bars

This paper presents results from two flume runs of an ongoing series examining flow structure, sediment transport and deposition in hydraulic jumps. It concludes in the presentation of a model for the development of sedimentary architecture, considered characteristic of a hydraulic jump over a non-eroding bed. In Run 1, a hydraulic jump was formed in sediment-free water over the solid plane sloping flume floor. Ultrasonic Doppler velocity profilers recorded the flow structure within the hydraulic jump in fine detail. Run 2 had identical initial flow conditions and a near-steady addition of sand, which formed beds with two distinct characteristics: a laterally extensive, basal, wedge-shaped massive sand bed overlain by cross-laminated sand beds. Each cross-laminated bed recorded the initiation and growth of a single surface feature, here defined as a hydraulic-jump unit bar . A small massive sand mound formed on the flume floor and grew upstream and downstream without migrating to form a unit bar. In the upstream portion of the unit bar, sand finer than the bulk load formed a set of laminae dipping upstream. This set passed downstream through the small volume of massive sand into a foreset, which was initially relatively coarse-grained and became finer-grained downstream. This downstream-fining coincided with cessation of the growth of the upstream-dipping cross-set. At intervals, a new bed feature developed above and upstream of the preceding hydraulic-jump unit bar and grew in the same way, with the foreset climbing the older unit bar. The composite architecture of the superimposed unit bars formed a fanning, climbing coset above the massive wedge, defined as one unit: a hydraulic-jump bar complex .     

Competition and co-operation in the semi-periphery: closer economic partnership and sectoral transformations in Chile and New Zealand

The signing of a strategic economic partnership (the Trans-Pacific SEP or P4) between Chile, New Zealand, Singapore and Brunei Darussalam in 2005 reveals the emergence of a new generation of trade agreements that seek to promote longer-term synergies and cooperation. This is in marked contrast with a purely competitive, market-based model of agreements whereby economies are opened up to oligopsonistic capital. The orientation is clearly more neostructural and strategic in construction, emphasizing the opportunities within the global economy of improved relations with similarly positioned economies within the semi-periphery. This article analyses both the basis for and implications of the P4 for Chile and New Zealand by looking at three sectors in which both countries are competitive in export markets: dairy, wine and fisheries. By assessing similarities and differences, and the ways in which competition or co-operation might be established, the potential impacts of the agreement can be posited. Within a global context of bilateral and multilateral commercial agreements, it is this type of agreement that perhaps best fits the needs of smaller economies in the periphery that seek to establish greater competitive space for their exports in core economies without engaging in a mutually destructive war of competition in similar sectors and products.     

A REVIEW OF GRAIN-SIZE PARAMETERS

This paper comprises a review of the many graphical and mathematical techniques that have been proposed for the statistical summary of grain-size data. Satellitic problems, such as laboratory techniques, choice of size scales, and interpretation, are only considered briefly.