Catalogue of the Palaeozoic plants in the Department of Geology and Palaeontology, British Museum (Natural History).

Bibliography: p. 265-275.

Pleistocene occupation of New Guinea's highland and subalpine environments

New Guinea's mountains provide an important case study for understanding early modern human environmental adaptability and early developments leading to agriculture. Evidence is presented showing that human colonization pre-dated 35ka (ka = thousands of uncalibrated radiocarbon years before present) and was accompanied by landscape modification using fire. Sorties into the subalpine zone may have occurred before the Late Glacial Maximum (LGM), and perhaps contributed to megafaunal extinction. Humans persisted in the intermontane valleys through the LGM and expanded rapidly into the subalpine on climatic warming, when burning and clearance may have retarded vegetation re-colonization. Plant food use dates from at least 31ka, confirming that some of New Guinea's distinctive agricultural practices date to the earliest millennia of human presence.

The palynology of the Plenmeller Coalfield and adjacent areas in Northern England

The samples collected in the present investigation from Featherstone, Plenmeller and adjacent areas in the North of England, yielded diverse, well preserved miospore assemblages with marked vertical variation, which compare fairly closely with those previously described from strata of the same age elsewhere. Six major Assemblages are recognised from coal and shale samples collected within Namurian and Westphalian A and B strata which have not previously been dated by miospore evidence. Oetailed comparisons are made with miospore assemblages previously described by several authors from similar stratigraphical horizons in Scotland, North England and. the Central Province. Formal taxonomic description is presented for 206 species belonging to 71 genera.tions 22 new types are described and one new combination is suggested.

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.

Elemental, biomarker, palynology and maceral data from Seam 1, Schöningen and associated interbeds

Sphagnum moss is the dominant plant type in modern boreal and (sub)arctic ombrotrophic bogs and is of particular interest due to its sensitivity to climate and its important role in wetland biogeochemistry. Here we reconstruct the occurrence of Sphagnum moss - and associated biogeochemical change - within a thermally immature, early Paleogene (~55 Ma) lignite from Schöningen, NW Germany using a high-resolution, multi-proxy approach. Changes in the abundance of Sphagnum-type spores and the C23/C31n-alkane ratio indicate the expansion of Sphagnum moss within the top of the lignite seam. This Sphagnum moss expansion is associated with the development of waterlogged conditions, analogous to what has been observed within modern ombrotrophic bogs. The similarity between biomarkers and palynology also indicates that the C23/C31n-alkane ratio may be a reliable chemotaxonomic indicator for Sphagnum during the early Paleogene. The d13C value of bacterial hopanes and mid-chain n-alkanes indicates that a rise in water table is not associated with a substantial increase in aerobic methanotrophy. The absence of very low d13C values within the top of the seam could reflect either less methanogenesis or less efficient methane oxidation under waterlogged sulphate-rich conditions.

Palynology of sediment profiles from 30 lakes in Germany

Dieser Datensatz beinhaltet 70 Pollenprofile und begleitende sedimentologische Daten aus 30 Seen in Deutschland, die im Verlauf der 70er und 80er Jahre vom NlfB gekernt und analysiert wurden. Der Datenatz wurde im Rahmen des im folgenden beschriebenen Teilprojektes des DFG-Schwerpunktprogrammes "Wandel der Geo-Biosphäre" von Prof. Dr. Josef Merkt der wissenschaftlichen Gemeinschaft zur Verfügung gestellt. Im Projekt "Laminierte Seesedimente als Archive für Untersuchungen der Änderungen von Umweltbedingungen während Spätglazial und Holozän" wurden die laminierten Abschnitte von Sedimentprofilen aus oberschwäbischen, nordschweizerischen und norddeutschen Seen, die die letzten 15 000 Jahre umfassten, mikroskopisch ausgewertet. Ziel war es für Deutschland eine jahrgenaue Chronologie nach Kalenderjahren aufzustellen. Poster: Kleinmann, A, Merkt, J, Müller, H, Küster, H (1998) Holocene lake-level changes in Germany. Institute of Geobotany, University Hannover & Geological Survey of Lower Saxony, Hannover. (pdf hdl:10013/epic.31687.d001 280kB) Einführung: Die meisten Seen in Deutschland bestehen seit mehr als 15 000 Jahren und sind seit Jahrtausenden attraktiv für menschliche Besiedlung. In den Seeablagerungen ist die Geschichte der Umwelt nahezu ungestört und hoch aufgelöst konserviert. Pflanzliche und tierische Reste, wie z. B. Blütenstaub, Birkenfrüchte, Bucheckern, Algen, Wasserflöhe, Käfer, Muschelkrebse und Rädertierchen können Auskunft über die Entwicklung der Flora und Fauna, über Wärme- und Kälteperioden seit der letzten Eiszeit bis heute geben. Weitere Zeugen sind z.B. klastischer Eintrag (wie Sand), vulkanische Aschen, chemische Ausfällungen und eine jahreszeitliche Schichtung, die nur unter Sauerstoffausschluß entsteht. Ist der Seegrund belüftet, leben dort Tiere, die die oberen Zentimeter des Seebodens zur Nahrungssuche durchwühlen und dabei diese Schichtung zerstören. Ist der Seegrund ganzjährig unbelüftet, bleiben die klastischen Partikel, die organischen Reste, die chemischen Fällungen wie Siderit und Kalzit in der Reihenfolge liegen wie sie abgesunken sind. Die Reihenfolge spiegelt den Ablauf der Jahreszeiten wider: Goldalgen fallen im Frühjahr und die Mehrheit der Kieselalgen im Frühsommer und Sommer auf den Seeboden. Eisenkarbonat und Kalk werden im Sommer ausgeschieden, die klastischen und organischen Partikel sedimentieren im Winter. Die Jahresschichten liefern das zeitliche Gerüst in dem sich Klimaumschwünge, Seespiegeltiefstände und andere Ereignisse der Paläoumwelt jahrgenau fassen lassen. Auch die Landnutzung durch den Menschen ist aus Seeablagerungen abzulesen, wie z. B. erster Ackerbau, Rodungshochphasen in der Römerzeit und im Mittelalter, Aufforstung Anfang des 19. Jahrhunderts, bronzezeitliche und jüngere Erzverhüttungen, Industrialisierung, sogar Atombombentests und das Reaktorunglück von Tschernobyl 1986. Diese deuten das umwelt-wissenschaftliche Potential der Seesedimente an. Wesentliche Antworten, die in Seesedimenten stecken und entschlüsselt werden, sind die auf Fragen nach Klimaänderungen und ihren Folgen. Neben den bekannten vulkanischen Aschenlagen Laacher Tuff aus der Eifel, Saksunarvatn Tuff aus Island und Kilian/Vasset Tuff aus dem Massif Central werden weitere gesucht, da sie trennscharfe Leithorizonte sind und zur absoluten zeitlichen Korrelation von See zu See dienen. Daneben können regional unterschiedliche Vegetationsentwicklungen über isochrone Tephralagen einander zugeordnet werden. Mit der Erfassung möglichst vieler Sedimentparameter können Kriterien gefunden werden, mit denen die natürlichen von den anthropogenen Umweltveränderungen zu unterscheiden sind. Klimatisch unruhige Zeitabschnitte wie der Übergang Alleröd/Jüngere Tundrenzeit vor 12700 Kalenderjahren, der Übergang Spätglazial/Holozän vor 11560 Kalenderjahren und die 120 Jahre später einsetzende vorübergehende Abkühlung, die Rammelbeekphase, wurden analysiert, um Dauer, Verlauf und Folgeerscheinungen kennenzulernen. Als Methoden wurden eingesetzt: Mikrofaziesanalyse mit Dünnschliffen, Pollenanalyse, Mikrofaunauntersuchungen, anorganisch und organisch geochemische Analysen, Isotopenanalyse (delta13C, delta18O, AMS an terrestrischen Makroresten).

Thermal decomposition of the synthetic hydrotalcite iowaite

The thermal stability and thermal decomposition pathways for synthetic iowaite have been determined using thermogravimetry in conjunction with evolved gas mass spectrometry. Chemical analysis showed the formula of the synthesised iowaite to be Mg6.27Fe1.73(Cl)1.07(OH)16(CO3)0.336.1H2O and X-ray diffraction confirms the layered structure. Dehydration of the iowaite occurred at 35 and 79°C. Dehydroxylation occurred at 254 and 291°C. Both steps were associated with the loss of CO2. Hydrogen chloride gas was evolved in two steps at 368 and 434°C. The products of the thermal decomposition were MgO and a spinel MgFe2O4. Experimentally it was found to be difficult to eliminate CO2 from inclusion in the interlayer during the synthesis of the iowaite compound and in this way the synthesised iowaite resembled the natural mineral.

New dimeric supramolecular structure of mixed (phthalocyaninato)(porphyrinato)-europium(III) sandwiches : preparation and spectroscopic characteristics

The mixed double-decker Eu\[Pc(15C5)4](TPP) (1) was obtained by base-catalysed tetramerisation of 4,5-dicyanobenzo-15-crown-5 using the half-sandwich complex Eu(TPP)(acac) (acac = acetylacetonate), generated in situ, as the template. For comparative studies, the mixed triple-decker complexes Eu2\[Pc(15C5)4](TPP)2 (2) and Eu2\[Pc(15C5)4]2(TPP) (3) were also synthesised by the raise-by-one-story method. These mixed ring sandwich complexes were characterised by various spectroscopic methods. Up to four one-electron oxidations and two one-electron reductions were revealed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). As shown by electronic absorption and infrared spectroscopy, supramolecular dimers (SM1 and SM3) were formed from the corresponding double-decker 1 and triple-decker 3 in the presence of potassium ions in MeOH/CHCl3.