Arm hooks of coleoid cephalopods from the Jurassic succession of the Wessex Basin,Southern England

The Jurassic succession of the Wessex Basin – especially that cropping out within the Dorset and East Devon Coast World Heritage Site – contains important lagerstätten for coleoid cephalopods. The Blue Lias and Charmouth Mudstone formations of West Dorset, the Oxford Clay Formation of North Wiltshire and the Kimmeridge Clay Formation of Purbeck have provided large numbers of important body fossils that inform our knowledge of coleoid palaeobiology, including the hooks present in the arms. Isolated hooks are also found in the processed residues studied by micropalaeontologists and these occurrences can be used – in some cases – to record the presence of key taxa in the absence of well-preserved body fossils. While some hook morphotypes can be attributed to known species, there are many forms of hook described where the parent animal remains unknown. The present state of our knowledge of the Jurassic assemblages in the Wessex Basin is presented and remaining issues identified.     

A commentary on coastal research in New Zealand universities

Abstract:    University research in coastal geomorphology, processes and management has made a major contribution to the fundamental understanding of coastal systems in New Zealand over the past 43 years. This article examines the growth in university-based coastal research since 1964 and discusses the geographical pattern and themes of this research. Data indicate a significant geographical concentration of research effort and focus on a narrow range of research themes. Underlying reasons for these characteristics of New Zealand coastal research are explored and challenges facing university based research are discussed. Such challenges can be overcome through a more coordinated research effort to realize the huge potential to undertake coastal science of national relevance and international significance.     

Geochemical studies to delineate topsoil contamination around an ash pond of a coal-based thermal power plant in India

In the present study, an attempt was made to delineate soil contamination around the ash pond of a coal-based thermal power plant. The topsoil in the study area was found to be contaminated to varying degrees from ash disposal. The soil drawn from various profiles was largely contaminated by ash fall out, predominantly in the prevalent wind direction. Pb, Zn, Cu, Ni, Co, Mn, Cr, V and Ba were found to be enriched in the topsoil around the ash pond with respect to the crust as well as the background, while Mn, V, Cr, Co and Ni were enriched compared to their maximum permissible concentrations prescribed for agricultural soils. These observations have been further strengthened from the contamination index map and lognormal distribution pattern of the elements. As a consequence of this contamination, many of the important physicochemical properties of topsoil in the direction of the wind have been modified significantly.Electronic Supplementary Material Supplementary material is available in the online version of this article at     

Statistical techniques and their application in palynology

The basic principals of hypothesis testing are reviewed, including the development of the hypothesis, the statistical assumptions made, and the test of the hypothesis. The appropriate experimental design and sampling technique for evaluation of hypotheses posed are discussed. Because the analysis of variance involving the F-test should be used in a wide variety of geological experiments, emphasis is placed on this analysis. Many geological experiments result in the measurement of one or more factors on a continuous scale, whereas others are recorded in a discrete fashion. This necessitates the use of a covariance analysis to evaluate the effect of discrete and continuous factors in the same model. Orthogonal comparisons are discussed as they are used to evaluate specific hypotheses following the general test of hypothesis in the analysis of variance or covariance. All procedures discussed are illustrated using actual palynofloral data.     

An experimental study of nonlinear baroclinic instability and mode selection in a large basin

This paper reports on two-layer rotating liquid experiments designed to study the behavior of non-linear baroclinic waves under conditions where the Rossby radius of deformation R_d is much smaller than the geometric length scale L imposed by the size of the laboratory apparatus. The apparatus is constructed to consistently simulate f-plane dynamics. When F = L²/R_d² > > 1, it is found that the unstable waves first encountered as friction is decreased have high frequencies, in accord with linear theory. As the friction parameter $\text{Q = 0.7 E}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}\text{/R}{}_0$ (where E is the Ekman number and R₀ the Rossby number) is further decreased into the non-linear region, singlewave amplitude vacillation is observed. Generally, as Q decreases lower frequencies (and low wavenumbers) dominate the response, which ultimately becomes turbulent at values of Q of the order 0.1. This is contrary to the result expected from an extrapolation of linear theory. Further observations show that the finite-amplitude state is not unique: multi-equilibria are possible depending on the initial conditions.     

Characterization of colloidal and particulate matter transported by the magela creek system,Northern Australia

The composition and amount of colloidal and suspended participate matter transported during a small flood event in Magela Creek in tropical northern Australia was investigated. The flood studied constituted approximately 3 % of the total annual flow, most (90%) of which occurred between mid-January and mid-February of the study year. Three fractions were separated from water samples using a sequential method involving a continuous flow centrifuge to separate suspended particulate matter (SPM; nominally > 1 μm) followed by hollow fibre filtration, first using a 0.1 μm filter to separate course colloidal matter (CCM; nominal size 1–0.1 μm) and then a 0–015 μm filter to separate fine colloidal matter (FCM; nominal size 0.1–0.015 μm). The SPM was predominantly inorganic (organic matter 21 %), whereas the colloidal fractions were dominantly organic matter (CCM 60%; FCM 83%). Analysis of individual particles using electron microprobe and automated image analysis indicated that the mineral fractions in both the SPM and CCM were dominated by iron-enriched aluminosilicates (including kaolinite) (72–82%) and quartz (9–10%), indicative of a highly weathered and extensively laterized catchment. Surprisingly there was very little difference in the composition of the SPM or CCM fractions during the flood event studied, which may indicate either that sediment availability was restricted following the major run-off events in January and February, or that all the sediment sources within the catchment are geochemically similar. Approximately the same amounts of particulate (20 tonne), colloidal (21 tonne) and dissolved material (17 tonne) were transported during the 25 hour period of the main flood peak; over 90% of the colloidal matter was 0.1–1.0 μm in size. These data suggest that previous estimates of the amounts of particulate (and colloidal) matter transported by Magela Creek, which were based on suspended solids measurements, may have underestimated the particulate matter load by as much as 50%. It is possible that the relatively high proportion of colloidal matter is unique to Magela Creek because coagulation and aggregation of colloidal matter to particulate matter is slow due to the very low concentations of calcium and magnesium in these waters. However, if the result is more widespread, there are important implications for the global estimates of fluvially transported particulate and dissolved materials as many of the previous studies may have underestimated the particulate load and overestimated the dissolved load.