Phytoclasts in palynofacies definition: the example of Rhaetian sedimentary organic matter in SE France

The aim of this paper is to calibrate palynofacies with eight classes of phytoclasts using statistical methods in order to construct a reference. Seven categories of palynomorphs are compared to the phytoclast reference. Principal components analysis (PCA) were performed, firstly using separated phytoclast and palynomorph parameters and, secondly, the two grouped describers on samples from two Rhaetian sections that outcrop in SE France. Factor plots of phytoclast data show an arrangement that we assume to be relevant to a crescent buoyant phytoclast order previously described by literature. This arrangement is associated with palynomorph describers (abundance of spores and acritarchs Micrhystridium and pollen Ovalipollis). Some lithological observations are antinomic with an interpretation of these groupings in terms of depositional energy but are presumably coherent with the water depth. Testing all the parameters simultaneously, we define six types of palynofacies ordered on a hypothesized water depth gradient, sustained by an inferred “buoyant factorial plan”. A low water depth palynofacies is associated with lagoons, beaches and marine-shelves. The phytoclasts present are the most buoyant particles on the palynomaceral arrangement. Bays, lagoons, foreshores, beaches, restricted-marine and marine-shelves produce the highest water depth palynofacies. The phytoclasts present are the poorest buoyant particles on the palynomaceral arrangement. Although the exact nature of the relations between energy, water depth and phytoclasts are unknown, the definition of palynofacies by PCA is an objective method for investigating and correlating sedimentary sections.     

A lamellibranch-stromatolite bioherm in the Lower Keuper (Ladinian, Middle Triassic), South Germany

Summary A unique small bioherm, 0.7 m in diameter and 0.25 m high, is described from the Lower Keuper in South Germany. Its core consists of the attached right valves of the tiny oyster-like lamellibranchPlacunopsis ostracina (Pectinacea). It is overgrown by a cm-thick laminated stromatolitic crust formed by microbial mats and sponges. The bioherm was dolomitized during early diagenesis and represents the temporary transition from restricted marine to more saline depositional environments. It is one of the stratigraphically youngestPlacunopsis bioherms found so far in the Germanic Triassic.     

Upper Ladinian to Lower Carnian sedimentary evolution in the Idrija-Cerkno Region,Western Sovenia

Summary An Upper Ladinian to Lower Carnian succession in the Idrija-Cerkno region (W Slovenia) is described and correlated with similar successions in the Dolomites. Structurally, the area belongs to the Rodne unit (Trnovo nappe, NW Dinarides). The succession was reconstructed from three stratigraphically superimposed sections. The Orehovska Grapa section is characterised by finegrained turbidites composed of sandy mudstones with intercalations of lenses and beds of trachy-andesite tuff and resedimented tuffs. Beds of hemipelagic light grey wackestone are rarely interstratified. These rocks are correlative with the Upper Ladinian Wengen Group. The Police1 section is composed of black shaly marls and mudstones, hemipelagic wackestone, tuffaceous sand-stones, and in the upper part, of calciturbidites overlain by black laminated shales. The section is correlated with the lower part of the San Cassiano Formation. The Police 2 section consists mainly of wavy bedded peloidal and bioclastic limestone, alternating with thin interbeds of shaly mudstones and marls. The limestone and mudstones are interpreted as tempestites and gradually pass into bedded and massive dolomite of Early Carnian age. This succession is similar to the transition from the San Cassiano Formation to the Cassian Dolomite. The studied succession represents a shallowing upward basinal sequence capped by carbonate platform deposits. Palaeogeographically it is a Late Ladinian transition from the carbonate platform in the south to the typical basinal area in the north.     

High-resolution sequence interpretation of epeiric shelf carbonates by means of palynofacies analysis: An example from the Germanic Triassic (Lower Muschelkalk, Anisian) of East Thuringia, Germany

Summary The Steudnitz quarry (East Thuringia, Germany) exposes the entire Lower Muschelkalk (Middle Triassic, Anisian) with a thickness of 103 m. In this paper, a primarily palynofacies-based sequence-stratigraphical interpretation supported by lithological investigations is proposed. Palynofacies of the sampled carbonate rocks is dominated by land-derived phytoclasts and pollen grains. Spores are quite rare. Marine plankton reaches its maximum abundance in an interval around the ThuringianSpiriferina-bed and the Terebratel-beds. In accordance with lithological features, this interval may be interpreted as a third-order maximum-flooding zone. Two different third-order interpretations are presented and discussed. Third-order sequences and parasequence sets can be identified by use of palynofacies analysis. Furthermore, palynofacies analysis provides an additional possibility of recognizing partly eroded or originally incomplete cycles (‘missed beats’). In some cases, a resolution down to the level of parasequences is possible. High-resolution palynofacies analysis is a powerful new tool in sedimentology but should always be combined with lithofacies interpretation. It provides very useful, additional information for high-resolution sequence analysis and palaeoenvironmental interpretation. Being a rather young method, high-resolution palynofacies analysis still shows some calibration problems with classical methods. However, these should be solvable by further research.     

The mud mound nature of the Cassian Platform Margins of the Dolomites A case history: the Cipit boulders from Punta Grohmann (Sasso Piatto Massif, northern Italy)

Summary The sedimentological features and the microbiofacies of the Cassian platforms (Late Ladinian-Carnian) of the Dolomites can be studied only on the basis of the socalled “Cipit boulders”, that are platform-derived olistoliths and clasts fed to the basin and escaped to the extensive dolomitization affecting the buildups. Our paper deals with the Cipit boulders occurring in the Punta Grohmann section (Wengen and S. Cassiano formations, Late Ladinian, Archelaus and Regoledanus Zones). The dominant microfacies are represented by boundstone, consisting of nearly 60% of micritic limestone occurring both as peloidal or aphanitic micrite, mostly organized into stromatolitic laminites of thrombolites. The skeletal organism (Tubiphytes, skeletal cyanobacteria, sphinctozoan sponges, etc.) represent only a minor component of the rock (usually less than 10%). Early cements are widespread and consist both of fan-shaped calcite (replacing former aragonite), bladed isopachous magnesian calcite and radial-fibrous calcite (neomorphic after Mg-calcite). The carbonate platforms from which the olistoliths derive were made up mainly of carbonate mud that underwent early lithification, as witnessed by the considerable amount of early cements: therefore they may be regarded to as mudmounds, and more precisely as microbial mud-mounds, due to the clearly accretionary, organic-controlled nature of most micrites. The micrites, subdivided into auto- and allomicrite on the basis of micromorphological and fabric characteristics, have been tested for epifluorescence. The results confirm the organic control on the deposition of automicrite, also in the cases in which a microbial influence is not obvious (i.e. aphanitic micrite without internal organization).     

Correlations among vegetation strata and environmental variables in subalpine spruce-fir forests,southeastern British Columbia

A set of forest vegetation-environment data consisting of 110 plots from subalpine spruce-fir forests in southeastern British Columbia was analyzed with multivariate methods. The aims were to describe and compare relationships among plots using species composition data from four strata of the forest (trees, shrubs, herbs, bryophytes), and to compare patterns in the separate strata with patterns in the environmental data. Weak but statistically significant correlations were detected among PCA axes from all four strata, with a tendency for correlations to be stronger between axes of adjacent strata. Relationships between stratal patterns and environmental variation were examined by correlating PCA axes with environmental variables separately, and jointly with canonical correlation analysis. Linear composites of the environmental data identified by the first canonical axis were similar for shrub, herb, and bryophyte strata implying similar responses to environmental variation in understorey strata; however, < 16% of the total variance was explained. No clear relationships emerged between tree stratum and environmental variation. Probable determinants of pattern in the tree stratum include historical events such as fire and winter snowpack, as well as possible interactions between species. Collectively, these events bear little resemblance to existing environmental conditions in the forest.Nomenclature used by BCMF follows Crum, Steere & Anderson (1973), Hale & Culberson (1970), and Stottler & Crandall-Stottler (1977) for non-vascular plants, and Taylor & MacBryde (1977) for vascular plants.The British Columbia Ministry of Forests provided the data on which this paper is based, as well as a grant to pay for the computer time used. We are grateful to G. Utzig for initially suggesting that a project of this nature be done, and to S. Phelps for helping with the retrieval of computer data files from tape. This paper has greatly benefited from discussions with P. Comeau and R. K. Scagel, and the comments of two anonymous reviewers.     

On the interpretation of principal components analysis in ecological contexts

Summary Principal components analysis is well suited for many data analysis problems in ecology, particularly for data reduction and hypothesis generation; but the structure of PCA is poorly suited for indirect gradient analysis. Whatever the intended application of PCA, the user must exercise special care in selecting data transformations to prevent the analysis from being overwhelmed by the purely numerical effects in the variance structure of the data.I would like to thank R. H. Whittaker, H. G. Gauch, R. E. Moeller, and S. R. Searle for their guidance and assistance.     

Congenital defects of the upper lateral incisors: Multivariate analysis of measurements of the other teeth,the superior arch,head and face

The survey of a French male population allowed us to ascertain 75 propositi with one or two missing ULI, 59 propositi with one or two reduced ULI and 99 controls on whom measurements (mesiodistal and buccolingual diameters) of all teeth of the superior arch are available. Principal Component Analysis gave a first estimated principal component highly correlated with each of the dental measurements or arch measurements. This size factor was eliminated by observing the plane of the second and third principal components. Strikingly different clusters of MD diameters or BL diameters were observed for the controls, the propositi missing one or two of the ULI and the propositi with reduced ULI. For the controls, the arch length is correlated with the MD molar diameters and the MD incisor diameter, the arch width being isolated from the other measurements. For the propositi with missing ULI, among the dental measurements the MD and BL diameters cluster, the arch length is isolated as are the arch widths. For the propositi with reduced ULI, the arch length is closer to the dental measurements while the widths, especially the first one, are isolated. The best discriminant measurements are the diameters of the first premolars and the canine, the first arch width and the arch length. Among controls, the arch is narrowed and shorter for the propositi with absence and wider for the propositi with reduction. Teeth measurements are always smaller in propositi.     

Statistical significance analysis of nuclear magnetic resonance-based metabonomics data

Use of nuclear magnetic resonance (NMR)-based metabonomics to search for human disease biomarkers is becoming increasingly common. For many researchers, the ultimate goal is translation from biomarker discovery to clinical application. Studies typically involve investigators from diverse educational and training backgrounds, including physicians, academic researchers, and clinical staff. In evaluating potential biomarkers, clinicians routinely use statistical significance testing language, whereas academicians typically use multivariate statistical analysis techniques that do not perform statistical significance evaluation. In this article, we outline an approach to integrate statistical significance testing with conventional principal components analysis data representation. A decision tree algorithm is introduced to select and apply appropriate statistical tests to loadings plot data, which are then heat map color-coded according to P score, enabling direct visual assessment of statistical significance. A multiple comparisons correction must be applied to determine P scores from which reliable inferences can be made. Knowledge of means and standard deviations of statistically significant buckets enabled computation of effect sizes and study sizes for a given statistical power. Methods were demonstrated using data from a previous study. Integrated metabonomics data assessment methodology should facilitate translation of NMR-based metabonomics discovery of human disease biomarkers to clinical use.     

Long Pleistocene pollen sequences from the Velay Plateau (Massif Central,France)

In June 1988, a 50-m-deep boring was made in the lacustrine infilling of the explosion crater of Ribains (Haute-Loire). On the basis of pollen analyses the following chronology is proposed for this sequence: 0–5.10 m, Holocene and Lateglacial (hiatus); 5.70–17.48 m, last pleniglacial; 17.48–27.70 m, early glacial; 27.70–31.55 m: last interglacial, referred to as the Ribains Interglacial; 31.55–53.50 m, penultimate glaciation. The zone between 32.0 and 22.5 m, corresponding to a thick diatomite layer, provided a detailed record of the last interglacial and the early glacial vegetation succession. This enabled precise correlations with the neighbouring site of Lac du Bouchet and other long European sequences, confirming the proposed chronology. In particular, the temperate phase correlated with the St-Germain I of Grande Pile is well characterized, as at Lac du Bouchet, by the presence of an abrupt cooling corresponding to the Montaigu Event. In contrast, the last pleniglacial deposits contain great amounts of reworked pollen from earlier temperate phases, this making a comparison with Lac du Bouchet impossible. The thick sequence representing the penultimate glaciation is also affected by sediment loss during coring. However, several cold episodes are recorded that are characterized either by a total absence of vegetation or by a treeless steppe vegetation or a Pinus woodland, like the successions observed in the last pleniglacial at Lac du Bouchet.

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Résumé En juin 1988 un sondage de 50 m a été réalisé dans les dépôts lacustres qui comblent le cratère d'explosion de Ribains (Haute-Loire). Les analyses polliniques conduisent à proposer pour cette séquence la chronologie suivante: 0–5,10 m, Holocène et Tardiglaciaire (hiatus); 5,70–17,48 m, dernier Pleniglaciaire; 17,48–27,70 m, glaciaire précoce; 27,70–31,55 m, dernier Interglaciaire, nommé Interglaciaire de Ribains; 31,55–53,50 m, penultième glaciation. Entre 32,0 et 22,5 m, l'enregistrement des successions de végétation du dernier interglaciaire et du glaciaire précoce est excellent car cet intervalle correspond à un épais dépôt de diatomites. Ceci permet d'établir des corrélations précises avec le site voisin du Lac du Bouchet et avec d'autres longues séquences européennes, qui justifient la chronologie adoptée. En particulier, la phase tempérée corrélée avec St-Germain I de la Grande Pile est bien caractérisée, comme au Lac du Bouchet, par la présence d'un court refroidissement abrupt correspondant à l'événement de Montaigu. Au contraire, les dépôts du dernier pléniglaciaire contiennent des quantités importantes de pollen secondaire remanié à partir des phases tempérées antérieures, rendant impossible toute comparaison avec le Lac du Bouchet. De même la très épaisse séquence correspondant au pénultième glaciaire est perturbée par de nombreuses pertes au sondage. Cependant sont individualisés plusieurs épisodes froids sans végétation, à végétation steppique non arborée ou avec boisement en Pinus qui évoquent les successions observées dans le dernier pléniglaciaire au Lac du Bouchet.

     

A Lower Silurian (Aeronian) radiolarian assemblage from black cherts of the Armorican Massif (France)

The Chalonnes-sur-Loire outcrop is the most complete Llandovery section in the Ligerian domain (Armorican Massif, NW France); it displays a ca. 10 m-thick sequence of organic-rich black bedded cherts alternating with black graptolitic shales, which were deposited above glaciomarine diamictites of the Hirnantian glaciation. It is likely the black cherts accumulated under eutrophic waters, on the outer shelf part (distal offshore) of a Gondwanan margin, situated at intermediate to high latitudes of the Southern hemisphere. Hydrofluoric acid processing allowed the extraction of radiolarians; seven species are identified in the best preserved sample discovered so far. All seven are common species in tropical assemblages known from Alaska and Nevada, which are characteristic of the Orbiculopylorum assemblage, of Aeronian to early Telychian age. This age is in good agreement with independent age control from graptolites in the Chalonnes section, suggestive of an Aeronian age for the radiolarian-yielding level.     

A morphometric analysis of extant and early miocene fossil hominoid maxillo-dental specimens

It is demonstrated in this paper that before we can hope to formulate phylogenetic relationships between and amongst fossil hominoid material it is first necessary to sex the material accurately. In order to determine whether the morphological and morphometrical variability seen in fossil specimens is due to sexual or inter species dimorphism, it is necessary to calibrate fossil specimens against extant hominoid species' morphologies. Only after fossil specimens have been sexed is it possible to differentiate between morphologies that are related to sex and those that are species specific. This will help reduce fossil misallocation. A morphometric analysis of extant and fossilProconsul hominoid material is presented. Each fossil specimen has been sexed according to symplesiomorphic sex morphologies as defined in this paper. After the fossil specimens have been sexed they are analyzed using multivariate statistics. The identification of differing sex patterns within the specimens examined here suggests that a new species ofProconsul may have to be considered.     

A principal components analysis of human odontometrics

It has long been recognized that tooth crown diameters in hominoids are all positively intercorrelated one with another. This study reports on sex-specific correlation matrices derived from 2,650 individuals from the Solomon Islands, Melanesia. Mesiodistal and buccolingual diameters of all permanent teeth from one side are used, excluding third molars. Analysis discloses significant sex dimorphism in the strengths of the intercorrelations, with females being better integrated. Principal components analysis (PCA) provides an objective means of data reduction (shown here to be preferable to simple size summation methods) and decorrelation of the resulting linear combinations. Four components are extracted (with results being virtually identical in the two sexes) and arguments are put forth that varimax rotation to "a simpler solution" may be counterproductive. Before rotation, the four components are 1) overall size, 2) buccolingual widths contrasted with mesiodistal lengths, 3) anterior (I,C) contrasted with posterior (P,M) teeth, and 4) premolars contrasted with molars. Most of the explained (shared) variance (63%) extracted by PCA is in overall size of the dentition. There is a strong urge to view the results of these principal components analyses as reflective of biologically and genetically meaningful entities.     

四川九顶山东坡植物群落的区系研究

对九顶山东坡植物群落野外调查 ,得到种子植物 10 4科 345属 4 85种。通过植物区系成分分析可知 ,该区区系比较复杂 ,15种分布类型在该区均有分布。其区系特征具有明显的温带性质 ,温带成分 2 0 1属 ,占总属的 5 8 2 6 % ,而且以北温带分布 (96属 )为主 ;与热带有一定的亲缘关系 ,热带成分 10 5属 ,占 30 4 3% ;中国特有植物多 ,17属 18种 ;区系起源古老。     

四川西部石渠地区夏季藏狐巢穴选择的生境分析

通过对四川石渠地区夏季藏狐洞穴生境选择的研究 ,以水源距离、洞口朝向、坡向、坡度、坡位、植被类型及鼠兔和鼠类洞穴等 7项指标为变量 ,运用主成分分析和聚类分析相结合的方法对收集到的 5 4个藏狐洞穴样本进行了分析。主成分分析在 4个主成分下达到 85 %的显著性。在第一主成分中水源距离、坡度和坡位是重要的影响变量 ,在另外 3个主成分中鼠类洞穴数量以及植被类型两变量也非常重要。聚类分析显示 ,5 4个洞穴样本在 3个水平上聚成 5类。藏狐易于选择草甸地带 ,中缓坡和低坡位 ,坡向多为阳坡或半阳坡 ,水源距离小于5 0 0m的地方筑巢 ,其穴口朝向多位于 135°～ 36 0°之间。此外 ,鼠兔和鼠类洞穴在藏狐洞穴样方内的出现 ,但数量变异较大 ,揭示小型哺乳动物和藏狐之间可能存在着复杂的相互关系。通过对四川石渠地区夏季藏狐洞穴生境选择的研究 ,以水源距离、洞口朝向、坡向、坡度、坡位、植被类型及鼠兔和鼠类洞穴等 7项指标为变量 ,运用主成分分析和聚类分析相结合的方法对收集到的 5 4个藏狐洞穴样本进行了分析。主成分分析在 4个主成分下达到 85 %的显著性。在第一主成分中水源距离、坡度和坡位是重要的影响变量 ,在另外 3个主成分中鼠类洞穴数量以及植被类型两变量也非常重要。聚类分析显示 ,5 4     

The Laboratory of Photosynthesis and its successors at Gif-sur-Yvette,France*

This article is not a survey of all the research made during the last half century at the ‘Laboratoire de Photosynthèse’ of the ‘Centre National de la Recherche Scientifique’ (CNRS) in Gif-sur-Yvette, but rather some personal recollections, as faithful as possible. Not all people could be mentioned and the scientists named here are mainly those who, at different stages of the laboratory's evolution, created their research teams, within or outside the laboratory. The laboratory, closed now as an administrative entity, was founded in 1953 by the CNRS in Gif-sur-Yvette, near Paris. Besides the emerging research groups in Paris and at Saclay, it was then the only one in France to be entirely dedicated to photosynthesis. Initially, the focus was on metabolic biochemistry of photosynthesis in whole plants and unicellular algae. In 1959, biophysics of primary and associated processes was added and in 1966, the laboratory was enlarged to include molecular genetics and, somewhat later, structural biology. Most of the early members of the laboratory have now gone offstage, but the research goes on, in Gif and elsewhere, thanks to the numerous high-level scientists that have been trained there. Most of the basic questions have now been answered, and interest has shifted in two directions, atomic and integrated, while many other facets of research are no longer specific to photosynthesis but part of more general biological problems, a normal situation for an area that has reached its maturity. This paper is dedicated to the scientists, technicians, students and visitors who could not all be cited here, but who contributed so much to the life of the laboratory. This revised version was published online in June 2006 with corrections to the Cover Date.     

Two populations of Phlebotomus ariasi in the Cévennes focus of leishmaniasis in the south of France revealed by analysis of cuticular hydrocarbons

Two distinct populations of Phlebotomus ariasi Tonnoir have been identified in the Cévennes focus of leishmaniasis in the south of France using gas-liquid chromatography (GLC) of cuticular hydrocarbons extracted from individual dried female flies. Results were obtained after analysis of flies collected from CDC light traps from a domestic and a sylvatic site separated by a distance of 900 m. Flies were provided for GLC analysis as six blind samples. Using cluster and discriminant analysis techniques, five of the samples were shown to form two distinct groups, while a sixth was identified as a mixture. These findings were subsequently confirmed to correspond exactly with the way the samples had been presented. Samples grouped together on the basis of the flies' cuticular hydrocarbon profiles had been taken from the same site, while the ungrouped sample had been deliberately mixed. Using a jack-knifed estimator, it is shown that specimens can be correctly allocated to the population to which they belong with a 92% success rate. These results confirm the value of the technique for the identification of populations of medical vectors. The implication of the findings for the epidemiology of leishmaniasis is discussed with special reference to the need to determine if both populations are vectors and to study differences in behaviour. In addition to adults, profiles of larval sandflies have been obtained for the first time.     

A multivariate analysis of fatness and relative fat patterning.

Skinfold measurements (triceps, subscapular, suprailiac and medial calf) in four samples (376 boys, 352 girs, 338 men and 380 women from rural Colombia) were subjected to principal components analysis to identify components of obesity and relative fat patterning. Three components emerged which were similar in the four samples: a first component of fatness explaining 70-80% of the variance and two fat pattern components each explaining 10-15% of the variance: trunk-extremity and upper-lower body. Fatness and the trunk-extremity pattern components changed with age in children (7-12 years), but none of the components changed with age in adults (25-60+). The fatter tended to be more patterned in both age groups. Canonical correlation analysis revealed that socioeconomic status was more related to fatness than to patterning. With the exception of brothers, all first degree relatives (sib, parent-off-spring) and spouses were correlated in fatness. Some of the correlations between relatives--usually sibs, but not spouses--were also significant for the pattern components, suggesting a genetic basis for the known stability of this characteristic (Garn, '55a). Principal components analysis is a useful multivariate alternative for quantitative studies of anthropometric patterning.     

Correlation between spatial distributions of pollen data, archaeological records and physical parameters from north-western France: a GIS and numerical analysis approach

New methodologies using Geographical Information Systems (GIS) and statistical tools were developed to provide new elements to the interpretation of fossil pollen records on the large spatial scale of north-western France. The originality of these methods lies in the analysis of the spatial distribution of the archaeobotanical data in order to identify correlations with other spatial parameters such as geological, climatic, pedological, topographical and archaeological characteristics. 218 pollen analyses from north-western France and a series of thematic maps (geological, archaeological, climatic, etc.) were used. The application of numerical analyses makes it possible to describe the spatial distribution of pollen data at a regional scale, and to identify spatial correlations between pollen data and other environmental parameters, and between archaeobotanical groups, archaeological and abiotic parameters simultaneously. Two examples are presented and discussed: (A) The spatial distributions of the predominance of hazel over oak between 6700 and 5700 cal b.p. and of modern precipitation are shown to be positively correlated, i.e. hazel is dominant in the most humid areas of the region. (B) The pollen data from the Bronze Age show associations of (1) pollen groups ascribed to meadows, shrubland, and forests with cooler temperatures, higher altitudes and northern latitudes, and (2) pollen groups ascribed to moor environments and anthropogenic vegetation with warmer temperatures, southern latitudes and lower altitudes. The latter implies that the agricultural landscapes of the Bronze Age were mainly confined to southern latitudes and low altitudes of the region, while the areas characterised by high altitudes and low temperatures were characterised by extensive activities such as grazing by cattle. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.