Did William Smith (1769–1839), the father of biostratigraphy,discover a Jurassic pterosaur tooth?

A partial, isolated tooth from the Middle Jurassic (Bathonian) Stonesfield ‘slate’ of the Taynton Limestone Formation of Oxfordshire is identified as likely coming from a ctenochasmatid pterosaur. Referral to Ctenochasmatidae is based on its very slender, slightly curved crown with near circular cross-section and subparallel margins, slightly inflated root and its stratigraphic age. The tooth is part of the William Smith fossil collection held at the Natural History Museum, London. The collection was assembled as part of William Smith's attempt to identify and map strata around England and Wales in the last decade of the 18th century and the first 15 years of the 19th century. Smith's extensive fossil collection of more than 2500 specimens was purchased by the British Museum in 1816 (Wigley et al., 2018), and thus the specimen is the first pterosaur to be accessioned to the national collection.     

Elastic strain effects in coherent perthitic feldspars

For coherent cryptoperthites, the compositions inferred from X-ray spacing curves are incorrect due to elastic distortions of the structure; a method is described for correcting these apparent compositions. This method uses the elastic compliances and stress-free lattice parameters to calculate the change in a ^* due to the coherency strain, and thus the corresponding compositional correction; this method applies only to cases in which both phases are monoclinic The magnitude of the correction depends on the bulk composition, but is typically on the order of 2 to 10 mol % Or. Compositional corrections calculated using this model are roughly half as large as those obtained using Smith's (1961) less rigorous constant volume method.     

William Smith's map brought alive by digital remastering

The geological mapping carried out by William Smith, which resulted in the publication of his famous map in 1815, was remarkable in many respects, not least because it relied on him being able to make consistent and accurate observations on the rock types he encountered during his fieldwork. This ability, gained from his many years studying rocks, allowed him to observe features with his own eyes (or at the very least, with the aid of a simple magnifying device) that others could not. We take a new look at William Smith's original stratigraphical sequences, and with samples collected from his classic field areas (many of which are around the city of Bath, Somerset, UK), demonstrate how spatial mineralogy mapping can be incorporated into the modern age of digital mapping.     

Additional observations on the evolution of Gryphaea

The view that Gryphaea became uncoiled as it evolved, recently presented by T. P. Burnaby (1965), is shown to be based on the incorrect use of a size dependent parameter. His result is largely the outcome of the larger mean size of the higher subzone specimens in Hallam's collections. When this size dependence is allowed for, then the results of Burnaby's method are similar to those given by Philip (1962). An additional treatment of Hallam's data is given and it is shown that the slopes of the reduced major axes fitted to Hallam's samples by Philip (1962) are an adequate index of the tightness of coiling (estimated by s/r) of the larger specimens in the samples. Limitations of Burnaby's method are briefly discussed.     

Stability properties of the Newmark,Houbolt and Wilson θ methods

This paper analysis the stability of several methods for obtaining numerical solutions of second-order ordinary differential equations. The methods are popular in structural and geotechnical engineering applications and are direct, that is they do not require the transformation of the second-order equation into a first-order system. They include Newmark's method in both implicit and explicit forms, Wilson's θ-method, Houbolt's method and some variants on this latter method. We shall examine the stability of the methods when applied to the second-order scalar test equation where a and c are real.     

Measurements of sand transport by wind on a natural beach

Bagnold's (1954) and Kawamura's (1951) formulae may be used for the calculation of the sand movement on a natural beach, provided the shear stress velocity U_* > 0·D4 m/s. Great discrepancies have been found between calculated and measured sand transport rates for U_* < 0·D4 m/s, mainly because of the capillary forces acting on a wet beach. The measured critical shear velocity U_*c at the beginning of sand movement on a clean dry beach agrees very well with that predicted by Bagnold's formula. On a dry beach where the sand grains are stuck together, U_*c was found to be about 10% higher. On a wet beach U_*c appeared to depend on the moisture content of the surface layer. Grain size is a determining parameter in the U_*c-moisture content relation. When the angle a between the wind direction at sea and the dune face is between 15° and 85° the streamlines of the wind will bend in the vicinity of the dune face. In consequence this may influence the direction of sediment movement.     

The succession of the Lower Old Red Sandstone (Siluro-Devonian) along the Ross-Tewkesbury Spur Motorway (M.50), Hereford and Worcester

The motorway cuts approximately 1900 m of strata, of which about 56 per cent are continuously exposed in numerous long sections, a new standard being afforded for the Lower Old Red Sandstone in the southern Welsh Borders. The succession recognized is: LOWER OLD RED SANDSTONE Brownstones (L. Dev.) at least 795 m St. Maughan's Group (L. Dev.) 630 m Raglan Marl Group (Siluro-Dev.) 385 m Clifford's Mesne Sandstone (Sil.) at least 9 m LUDLOW SERIES (Silurian) at least 5 m The uppermost Ludlow Series and the Clifford's Mesne Sandstone are exposed in the core of the May Hill-Woolhope upfold. They are overlain in the complimentary syncline to the west by the Raglan Marl Group, St. Maughan's Group and Brownstones, in ascending order. Above the Clifford's Mesne Sandstone, there is a progressive upward increase in the number and thickness of sandstone relative to mudstone beds. Pedogenic limestones are largely concentrated in two short stratigraphic intervals. The lowest, mainly in the uppermost Raglan Marl Group but reaching into the St. Maughan's Group, includes the “Psammosteus” Limestone recognised elsewhere in the area. The second concentration occurs in the uppermost St. Maughan's Group. Vertebrates in the Raglan Marl Group and the St. Maughan's Group allow the Downtonian and Dittonian “stages” to be recognized.     

Yangtzedonta is Undoubtedly a Junior Synonym of Xianfengella

With the verification of the type specimen by six experts from the Nanjing Institute of Geology and Palaeontology, the specimen of Xianfengella prima He and Yang, 1982 described by Qian （Qian, 2001, flge2： la-c） is confirmed to be the holotype specimen （NIGP. 84430） of Yangtzedonta primitiva Yu, 1985, and consequently, Yu Wen＇s view that they are not the same specimen is impractical. This fact demonstrates that Yangtzedonta primitiva Yu, 1985 is undoubtedly a junior synonym of Xianftngella prima He and Yang, 1982, and is invalid. Qian＇s conclusion （Qian, 2001 ） that no bivalve appeared in the early Meishucunian Stage of the Early Cambrian is rational.     

两类经典滑坡发生时间预报模型的理论分析

老化和应变速率对土体强度和变形性质的影响研究,以及野外事例观察,已经证实大多数滑坡的形成机制可以由深部蠕变理论解释。土体蠕动速率在滑坡爆发之前将随着造成滑坡因素的增加而增加。根据这一理论,人们可以建立早期滑动的唯象蠕变方程来预测滑坡。早期的这类代表模型是Saito模型和Voight模型。本文重新进行的理论分析表明:这些模型具有丰富的理论内涵和深入的理论基础,具备滑坡预报模型要求的所有条件,包含的参数物理意义明确,因而具有新的生命力。      

Analytical prediction of aggregates' effects on the ITZ volume fraction and Young's modulus of concrete

In order to evaluate analytically the ITZ volume fraction (f_ITZ) in concrete, a three phase model is proposed for the random concrete microstructure using the Voronoï tessellation. Within this model, the ITZ local thickness is a statistical variable depending on the local paste thickness available between each couple of neighbouring aggregates. The f_ITZ is found to not exceed 7% for typical concretes. Then, the concrete Young's modulus is predicted analytically using a four‐phase generalized self consistent model but in which the proposed f_ITZ is considered. It is found that the concrete Young's modulus increases when increasing aggregates volume fraction, aggregates maximum size and the proportion of coarse aggregates and when decreasing the ITZ thickness and Young's modulus. Finally, the validity of the proposed model is discussed based on a comparison between its predictions and three sets of experimental results related to normal and high strength concretes taken from literature. Copyright © 2016 John Wiley & Sons, Ltd.     

A rediscovered fossil locality at Shedden,near Burnley,Lancashire

Carbonicola agrestis (Brown 1843), described with C. heyae, C. rugosa and C. smithii, were recorded from “Ironstone Shale” at or near “Sheden”, a locality lost for many years. Non-marine bivalves closely comparable with Brown's figures of C. agrestis and C. heyae were recently discovered in an old tip at Shedden, about 6–5 km south-east of Burnley. With other evidence the material suggests that Brown's species were collected from a small mine in this locality and from a horizon not more than 3.7 m above the Arley Mine.     

Two formulations for dynamic response of a cylindrical cavity in cross‐anisotropic porous media

Two formulations for calculating dynamic response of a cylindrical cavity in cross‐anisotropic porous media based on complex functions theory are presented. The basis of the method is the solution of Biot's consolidation equations in the complex plane. Employing two groups of potential functions for solid skeleton and pore fluid (each group includes three functions), the u–w formulation of Biot's equations are solved. Difference of these two solutions refers to use of two various potential functions. Equations for calculating stress, displacement and pore pressure fields of the medium are mentioned based on each two formulations. Copyright © 2009 John Wiley & Sons, Ltd.     

The formation of dunes,antidunes, and rapidly damping waves in alluvial channels

Under the effect of a constant current for a long time, a water channel of infinitely long and constant depth interacting with a uniform sandbed of infinite thickness is used to simulate the formation of dunes, antidunes and rapidly damping waves in alluvial channels. The theory of potential flow is applied to the channel flow, while Biot's theory of poroelasticity is adopted to deal with erodible bed material. The governing equations, together with free surface, bed surface, and far field boundary conditions, form a complete boundary‐value problem without applying empirical sediment discharge formulas as in conventional researches. The comparison of the present result with Kennedy's (Journal of Fluid Mechanics, 1963; 16 : 521–544) instability analysis not only indicates the appropriateness of the present work, but also reveals the advantage of the present study due to its ability to find all kinds of bed forms (including the rapidly damping waves that Kennedy could not find) and of solving for the unclear lagged distance δ introduced in Kennedy's work. Copyright © 2001 John Wiley & Sons, Ltd.     

Methods of computation of suspended load from bed materials and flow parameters

Computation of the grain-size distribution of the suspended load above a sand bed must take into consideration: (1) sorting processes from the bed to the bed layer and (2) sorting between the bed layer and suspension. Grain-size distributions of the bed layers above sand beds of three different types have been computed in this work, both by the Einstein and the Gessler methods. Using these as references, suspended load distributions have been obtained in each case by the Rouse suspension equation. A new formula has also been developed in partial modification of Hunt's method for direct computation of bed load and suspended load from a bed's grain-size distribution and flow parameters. Comparison of the computed data with actual observations in laboratory flumes show that no one method is particularly superior to the others, but the present method is advantageous because it affords direct computation of the suspended load from a bed's grain-size distribution, without going through an intermediate stage (bed load). The possible sources of error in each of the methods have been discussed.     

Blueschist facies metamorphism in Nordenskiöld Land of west‐central Svalbard

Recent fieldwork in Nordenskiöld Land, Svalbard's Southwestern Basement Province, has established the presence of high‐pressure (HP) lithologies. They are strongly retrogressed blueschists consisting mainly of garnet and Ca‐amphibole with remnants of ferroglaucophane and phengite. The pressure–temperature (P–T) conditions were estimated using phase equilibrium modelling in the NCKFMMnASHTO system. P–T estimates based on the garnet, phengite and ferroglaucophane compositional isopleths and modelled paragenetic assemblage indicate peak metamorphism at 470–490 °C and 14–18 kbar. These data fall close to the 7–8 °C km^?1 geotherm, which is similar to that from Motalafjella, the only previously known occurrence of blueschists in Svalbard's Caledonides. The newly discovered blueschists could have formed during the early stage of the Caledonian Orogeny and may represent a vestige of missing marginal basins of the western Iapetus developed at the onset of subduction. The likely counterpart to Svalbard's blueschists is the ophiolitic sequence in the Pearya Terrane of northern Ellesmere Island.     

生物纳米FeS包覆层对灰岩中和能力的影响

本文采用硫酸盐还原菌(SRB)和嗜酸铁还原菌(JF-5)合成纳米FeS,并将其包覆在灰岩表面,采用溶解动力学实验研究了不同纳米FeS包覆层对灰岩溶解和中和能力的影响。结果表明,X射线衍射表面包覆层矿物为纳米的四方硫铁矿,光电子能谱(XPS)结果进一步显示包覆层中Fe的价态为+2,S的价态为-2;包覆层对灰岩的溶解有明显的钝化影响,中和能力随厚度的增加而降低,最厚包覆层的存在能够使最终中和p H值降低1.5个单位。利用Frick第一定律推导了包覆层存在下灰岩的溶解过程公式,建立了包覆层溶解动态模型。     

Les foraminifères agglutinants du Quaternaire récent dans le domaine profond du Golfe de Gascogne

The bathymetric distribution of recent arenacous Foraminifera has been studied in samples from the bottom surface in the Bay of Biscay, from depths of between 560 and 4450 m. Comparison could be made with the results obtained by Saidova from the Pacific Ocean. These forms have been studied in late Quaternary cores from the same area. This microfauna is very abundant and characteristic of the late Holocene. Some species are of stratigraphic or climatic index value: the rapid decline of Siphotextularia rolshauseni characterizes the beginning of the late Holocene. Adercotryma glomerata now lives at depths exceeding 3500 m, but at least up to the middle Würm it lived on the continental slope. Karreriella is represented only after the Würm II-Würm III interstade. Eggerella is represented at least since the end of Riss and disappears during Würm III. Some genera may provide information on the foraminiferal invasion of the abyssal plain. Les foraminifères agglutinants récents sont étudiés dans divers échantillons prélevés à la surface du fond marin du Golfe de Gascogne, entre 560 et 4450 m de profondeur; ainsi peut-on envisager la distribution bathymétrique de ces formes et comparer nos résultats avec ceux obtenus par Saidova dans l'Océan Pacifique. Une série de carottes prélevées dans la m eme région permet létude de ces foraminiféres agglutinants durant le Pleistocéne supérieur. Cette microfaune est trés abondante durant lépisode le plus récent de l'Holocéne qu'elle caractérise. Certaines formes peuvent aussi servir de repères stratigraphiques ou climatologiques: Siphotextularia rolshauseni caractérise, par sa disparition brutale, la partie la plus récente de l'Holocène. Adercotryma glomerata vit actuellement audelà de 3500 m, mais habitait la pente continentale au moins jusqu'au Würm moyen. Karreriella se manifeste seulement depuis l'interstade Würm II-Würm III. Eggerella, présent depuis au moins le sommet du Riss, disparait durant le Würm III. Enfin, certains genres nous permettent d'aborder le problème de l'origine du peuplement des grands fonds.     

The effect of Poisson's ratio and the far-field boundary conditions on the accuracy of finite element calculations

It is shown that a finite element calculation which approximates an ‘infinite medium’; problem by a mesh with finite boundaries will yield greater accuracy when stress boundary conditions are applied on the far-field boundary than is obtainable with displacement boundary conditions. In particular, with Poisson's ratio close to 0.5, the accuracy of the latter model is severely impaired, whereas the stress boundary condition model is unaffected for Poisson's ratio of 0.49 and a reasonable mesh. The eight-node quadratic isoparametric element displays superb accuracy for the axisymmetric thick cylinder with either type of boundary condition.     

Beecher's Trilobite Bed

Beecher's Trilobite Bed in the Upper Ordovician of New York State has yielded some of the most completely preserved trilobites. Abundant specimens of Triarthrus, and fewer of Cryptolithus, were buried in a single catastrophic influx of sediment, and the limbs and other features are preserved in pyrite. A recent re-excavation of the bed provided an opportunity to investigate the controls on the pyritization of soft tissues, an extremely rare phenomenon. Larval and juvenile specimens are common in the Trilobite Bed, allowing the life histories of the trilobites to be pieced together. The nature of the transition from larva to adult was significant in determining the trilobites' chances of surviving the mass extinction at the end of the Ordovician.     

Relations between load and settlement of circular foundations on or in a dense sand expressed by a function of diameter and depth

When load acts on a circular foundation on or in a dense sand, average contact pressure on the lower surface of the foundation is q and settlement of the foundation is s. Diameter and depth of the foundation are B and D_f. When the sand, B and D_f are given, we can know the relation between q and s/B by, e.g. a loading test, i.e. the relation is determined by B and D_f for the sand. Using the results of numerical analyses, we express a relation between q and s/B up to s=0.1B by functions of a single variable which is a linear combination of B and D_f. Consequently when two foundations have different B's and different D_f's but have the same value of the variable, the relations are the same. Then we examine whether the functions can express the results of eleven tests of model foundations of wide range of B and/or D_f. In all the tests, the relations are expressed with sufficient accuracy. Copyright © 2005 John Wiley & Sons, Ltd.