The palynology of carboniferous strata in Northumberland off-shore boreholes

The work described represents a palynological study of Carboniferous coal seams of Upper Westphallan. A and Westphalian B age from eight off-shore boreholes sunk by the National Coal Board in Northumberland. When treated chemically the majority of the coal samples yielded well-preserved miospores which were studied by means of the optical and scanning electron microscopes. Systematic descriptions of 151 miospore species belonging to 57 genera, and including 18 new types, are given. One miospore assemblage is recognised from the coals of Upper Westphalian A age and two fUrther assemblages from those of Westphalian B age, These compare with assemblages described by earlier workers from strata of similar age elsewhere, but there are differences in the distributions of some of the more abundant taxa, and some of the stratigraphically significant species are not present. Correlations based on miospore distributions between the coal seams encountered in the eight off-shore boreholes agree fairly closely with those established by the National Coal Board on lithological criteria. Relations are discussed between palynology and palaeoecology and detailed comparisons made with the work of Smith and Butterworth 1967 from the adjacent on-shore area. It is concluded that the miospore assemblages described are restricted in that they contain very low representation of Smith's (1962) Densospore phase. This restriction, due to the relatively rapid subsidence of the depositional area, is reflected in the distributions of some of the less common spores as · well as in the abundances of species such as Densosporites sphaerotriangularis, Lycospora pusilla and Apiculatisporis irregularis.

Sedimentology, palaeontology and diagenesis of the Much Wenlock limestone formation

Lithofacies distribution indicates that the Much Wenlock Limestone Formation of England and South Wales was desposited on a shelf which was flat and gently subsiding in the north, but topographically variable in the south. Limestone deposition in the north began with 12m of alga-rich limestone, which formed an upward shoaling sequence. Deepening then led to deposition of calcareous silty mudstones on the northern shelf. The remainder of the formation in this area formed during a shelf-wide regression, culminating in the production of an E to W younging sandbody. Lithofacies distribution on the southern shelf was primarily controlled by local subsidence. Six bedded lithofacies are recognised which contain 14 brachiopod/bryozoan dominated assemblages, of which 11 are in situ and three consist of reworked fossils. Microfacies analysis is necessary to distinguish assemblages which reflect original communities from those which reflect sedimentary processes. Turbulence, substrate-type, ease of feeding and other organisms in the environment controlled faunal distribution. Reefs were built dominantly by corals, stromatoporoids, algae and crinoids. Coral/stromatoporoid (Type A) reefs are common, particularly on the northern shelf, where they formed in response to shallowing, ultimately growing in front of the advancing carbonate sandbody. Algae dominate Type B and Type C reefs, reflecting growth in areas of poor water circulation. Lithification of the formation began in the marine-phreatic environment with precipitation of aragonite and high Mg calcite, which was subsequently altered to turbid low Mg calcite. Younger clear spars post-date secondary void formation. The pre-compactional clear spars have features which resemble the products of meteoric water diagenesis, but freshwater did not enter the formation at this time. The pre-compactional spars were precipitated by waters forced from the surrounding silty mudstones at shallow burial depths. Late diagenetic products are stylolites, compaction fractures and burial cements.

Recent and Miocene carbonate sediments from Indonesia. Available in 2 volumes.

Mapping and sediment sampling in reefs of the Pulau Seribu group (southwest Java Sea) shows the existence of ten physiographic zones and subzones represented by seven lithofacies. Reefs in the northern part of the archipelago are smaller, more closely spaced and morphologically sim pler than those in the south. This pattern is attributed to differences in subsidence rate. A th reedimensional model is proposed for the evo lution of these reefs but borehole data are requi red to test this model. Miocene limestones are described in detail from hydrocarbon reservoirs in the Batu Raja Formation of the same area. Brief comparisons a re made with surface outcrops of approximately coeval carbonate developments. The lithofacies developed within these limestones reflect variations in hydrodynam ic regime and basement topography . Ele\le.n diagenetic processes affected the Batu Raja limestones and the dist ribution of these is primarily related to sealevel fluctuations. Early diagenesis was marine and characterised by micritisation and preCipitation of fibrous and bladed cements. Dolomitisat ion occurred in the mixed- water zone and its variable intensity is attributed to the configuration of the carbonate body relative to this zone. Subsequently the limestones were subjected to freshwater phreatic zone diagenesis resulting in dissolution and cementation, and a t a late stage underwent burial compaction. Secondary porosity, which \ar9e1.y determines the suitability of these limestones as hydrocarbon reserVOirs, is a function of the variable intensity of dissolution and cementation, burial compaction, dolomitisation and possibly micrite neomorphism. The sedimentary processes that generated the Batu Raja buildups are inferred f rom comparisons with the Pulau Seribu and other Recent analogues. The contrasting pinnacle form of the Pulau Seribu patch reefs compared with the low relief of the Batu Raja buUdups results from differences in the initial substrate topography and subsequent subsidence rate

The far right vote in France:from consolidation to collapse?

The presidential and legislative elections of 2007 are widely seen to have marked the end of the far right as a major political force in France. How could this occur only five years after Le Pen’s qualification for the presidential run-off, and with his party seemingly in the ascendant? This article discusses recent fluctuations in far-right electoral performance in France. It focuses largely on the presidential elections of 2002 and 2007, re-examining the (supposed) upswell of far-right support in 2002 and its (supposed) subsidence in 2007. Both elections require nuanced interpretation. Both confounded poll predictions, which in 2007 failed to measure the effect of Sarkozy’s hard-right campaign and, crucially, the extent to which the border between “mainstream right” and “far right” had shifted since 2002. This allowed Sarkozy to drain part of Le Pen’s electorate, and raises questions over the longer-term impact of Le Pen and the FN on the political agenda in France.