Hook Head Research Articles

Discovery and recovery of an exceptional accumulation of Carboniferous echinoids at Hook Head, Wexford

Geoconservation is a burgeoning area of activity within the Earth sciences and the preservation of significant fossil finds remains crucial for the advancement of palaeontological knowledge and protection of geoheritage. Here, we report on the discovery of an unusually large and remarkably well-preserved cluster of Carboniferous echinoids at Hook Head in County Wexford, Ireland. The fossil accumulation was located in the upper part of the Ballysteen Limestone Formation, which is Tournaisian in age and records sedimentation on a mixed carbonate-siliciclastic shelf/ramp. The fossil record of Paleozoic echinoids is generally poorly sampled; however, the fossil cluster from Hook Head includes at least 250 partially imbricated echinoid specimens in close association and preserves features such as the spines, Aristotle's lantern and peristomal plates. The fossil-bearing surface was precariously located on a coastal outcrop and at serious risk of being removed by storm activity, prompting an emergency rescue operation. The successful recovery of this important fossil find, which included securing official permission for extraction of the slab and its lodgement with the National Museum of Ireland, represents something of a first for Irish geological conservation.

Discovery and Recovery of an Exceptional Accumulation of Carboniferous Echinoids at Hook Head, Wexford.

Geoconservation is a burgeoning area of activity within the Earth sciences and the preservation of significant fossil finds remains crucial for the advancement of palaeontological knowledge and protection of geoheritage. Here, we report on the discovery of an unusually large and remarkably well-preserved cluster of Carboniferous echinoids at Hook Head in County Wexford, Ireland. The fossil accumulation was located in the upper part of the Ballysteen Limestone Formation, which is Tournaisian in age and records sedimentation on a mixed carbonate-siliciclastic shelf/ramp. The fossil record of Paleozoic echinoids is generally poorly sampled; however, the fossil cluster from Hook Head includes at least 250 partially imbricated echinoid specimens in close association and preserves features such as the spines, Aristotle’s lantern and peristomal plates. The fossil-bearing surface was precariously located on a coastal outcrop and at serious risk of being removed by storm activity, prompting an emergency rescue operation. The successful recovery of this important fossil find, which included securing official permission for extraction of the slab and its lodgement with the National Museum of Ireland, represents something of a first for Irish geological conservation.

Development and Application of R pin insulator insulating rod with pincer

In the field of live working of transmission lines, the R pin insulator has been put into application as an emerging type of insulator connection in recent years. In view of the difficulty in eliminating the prior art and tools, and affected by the working environment, this scheme has designed a kind of R pin insulator insulating rod with pincer. The design scheme consists of a hook body and connecting members, an insulating operating rod, etc., and does not change the operation method of the original insulating rod for the pincer, and the hook head is horizontally moved by the rotation of the nut to achieve the loading and taking of the R type limiting pin. The deductor has a simple structure, is simple and flexible to operate, and is convenient to carry. The process of taking off the sales is less difficult, greatly shortening the time, improving the efficiency of the work, and achieving the purpose of optimizing the operation process. And it has a broad market prospects.

Case Study of Potential Vorticity Tower in Three Explosive Cyclones over Eastern Asia

AbstractThree cases of explosively developing extratropical cyclones over eastern Asia are analyzed using ERA-Interim data. The morphological characteristics of the upper-tropospheric potential vorticity (PV) were examined. The common feature of all of these three cases is a hook-shaped high-PV streamer wrapping counterclockwise around the center of surface cyclones on the southern and eastern sides and an arch-shaped low-PV tongue that wrapped the high-PV hook head from the north. The hook-shaped high-PV tongue overlaps with the maximum centers of both the relative vorticity and static stability parameter, indicating the stratospheric nature of the PV source inside the hook-shaped high-PV tongue.The analysis indicates that there existed a deep tower of high PV above the surface cyclone at the time when these cyclones underwent explosive cyclogenesis. The high PV in the upper troposphere originates from the polar stratospheric PV reservoir associated with the tropopause-folding process. The high PV in the lower troposphere, however, is associated with the latent heat release, as nearly 70%–90% of the high-PV values in the lower troposphere reside in the region where the rainfall is the heaviest.

Multilevel Direct Repair Surgery for Three-Level Lumbar Spondylolysis

A 45-year-old man presented to our clinic requesting evaluation for surgical treatment of chronic low back pain of more than 20 years duration. He was diagnosed with 3-level lumbar spondylolysis at L3–5. Direct repair using the pedicle screw and hook-rod system was conducted for all three levels. After the surgery, his low back pain completely disappeared. Six months later, he felt discomfort and heard a metallic sound as he twisted his trunk. Computed tomography and radiography indicated that the hook head for L3 and the screw head for L4 were interfering with each other, causing the sound. We confirmed bony union at L3 and removed the L3 system. Surgeons should be aware of such complications if direct repair using a pedicle screw and hook-rod system is conducted for multilevel spondylolysis.

Effect of magnetized water on morphologically abnormal sperms and histopathological status of testis in mice

ifty white Swiss male mice (6-7) weeks of age were randomly divided into two groups, and each group included 25 mice. Group 1 (treatment group) were get magnetic water, group 2 (control group) were get tap water. After whole experimental period (16 weeks), Animals sacrificed and sperms were collected from epididimyes, then histopathology for testis tissue was done and morphologically abnormal sperm of head sperm percentage were calculated. Results revealed that abnormalities of head sperm percentage in treatment group 0.99% were reduced compared with control group 1.03%, but the differences were not significant. Means of narrow head, loss hook head, hammer head and bacillary head in control group were insignificantly (P>0.05) more than treatment group, but mean of spherical head in treatment group 1.63 was mathematically higher than its similar in control group 1.44, simple correlation coefficient between all kinds of abnormalities was insignificant except that between loss hook head and hammer head (-0.27) which exhibited significant differences (p<0.05). No significant reduction was observed in motality percentage of sperms, dead and abnormalities of sperms in the treatment group compared to control group. Significant increase (P<0.01) was observed in seminiferous tubules diameters in the treatment group, whereas primary spermatocytes, spermatids and interstitial spaces exhibited insignificant increase in treatment group compared with control group.

Calendar Scale, Environmental Variation Preserved in the Skeletal Phenotype of a Fossil Bryozoan (Rhombopora blakei n. sp.), from the Mississippian of Ireland

A single large colony (20 cm) of Rhombopora blakei n. sp. from the Hook Head Formation of Ireland (Tournaisian Stage, Mississippian) permits an analysis of within-colony variation associated with environmental change at a calendar scale (days to decades). Morphometric data for three external characters—apertures spacing along a branch and diagonal to a branch as well as lateral zooecial spacing—were collected as growth series (16–30 generations) from 13 segments within the colony. ANOVA, post-hoc means testing and graphical analysis of standardized data revealed nearest neighbor effects at the zooecial level and non-random distribution of variances across the colony. Parametric tests for sequential nonrandomness revealed cyclic variation through growth transects at three levels (23.3, 9.4 and 5.3 generations). Comparisons to growth rates of modern bryozoans suggests that the longer-term cycles are annual and that the shortest cycles may be related to lunar tidal cycles. The exceptional size and preservation of this single specimen, which is a new species of rhabdomesine Bryozoa, reinforces the importance of collecting individual morphological measurements from randomly selected and widely spaced parts of a colony for taxonomic, evolutionary and ecological applications.

The Lower Carboniferous (Tournaisian) Crinoids from Hook Head, County Wexford, Ireland

The Lower Carboniferous (Tournaisian) Crinoids from Hook Head, County Wexford, Ireland

Biting back at Hook Head

Biting back at Hook Head

Biting back at Hook Head

Biting back at Hook Head

All is not well at Hook Head

All is not well at Hook Head

All is not well at Hook Head

All is not well at Hook Head

Different theory and practice at Hook Head

Different theory and practice at Hook Head

Taphonomy of Lower Carboniferous crinoids from the Hook Head Formation, Ireland

Ausich, W.I. & Sevastopulo, G.D. 1994 10 15: Taphonomy of Lower Carboniferous crinoids from the Hook Head Formation, Ireland. Lower Carboniferous strata at Hook Head, County Wexford, Ireland, record tempestite deposition on a mixed carbonate and siliciclastic shelf-ramp. Crinoidal remains occur in all facies, which allows for a comparative taphonomic analysis of crinoid preservation. Preservation of crinoid crowns was controlled by a balance between mean storm intensity and frequency. The best preservation occurs at moderate depths. Taphonomic resistance among Hook Head crinoids is interpreted as follows (from most to least resistant to disarticulation): monobathrid camerates -cladids - diplobathrid camerates — flexibles (with Platycrinites and Dichocrinus disarticulation more like cladids). Crinoidea, taphonomy, preservation, Lower Carboniferous, Ireland.

A Petrified Lycopod from the Uppermost Devonian of Hook Head, County Wexford, Ireland

A collection of pyritic permineralized axes of a new lycopod were made at Hook Head, County Wexford, Ireland, during the summers of 1982 and 1983. The fossil-bearing rocks are Latest Devonian (= Tournaisian 1a). The holotype of Wexfordia hookense gen. et sp. nov. consists of a forked axis of only primary tissues. The vascular tissue is organized into a medullated stele. The center of the axis is parenchymatous and surrounded by a smooth-surfaced cylinder of primary xylem. The tracheids are scalariform with vertical connections between scalariform bars. Protoxylem is peripheral, appearing at times as minute projections of the stelar surface. Presumed primary phloem occurs in a narrow band, 2-4 cells wide, surrounding the xylem. Phloem cells are elongate and thin-walled, and may have a beaded pattern on the walls in longitudinal section. The cortex is two-zoned: an inner cortex of polyhedral parenchymatous cells and an outer cortex of parenchyma cells that are isodiametrical in transverse section and elongate in longitudinal section. Leaf traces originate as terete strands of protoxylem and are associated, immediately, with an abaxial parichnos (lacuna). The parichnos extends into the leaf, becoming a central canal. Leaf bases are circular to oval and persist. Leaves, up to 3.6 mm wide and at least 4 mm long, consist of a thickened midrib with a canal and vascular strand and thinner wings on either side. Leaves are crowded, overlap, and are slightly deflexed at their base, then curve upward to become appressed. The new plant reveals a combination of characters intermediate between the Devonian Protolepidodendrales and the Upper Carboniferous Lepidodendrales.

Beaconites-type burrows from the Old Red Sandstone of Hook Head, Co. Wexford, Ireland

Burrows are numerous at several levels of the Late Devonian fluvial red beds of the Harrylock Formation, Hook Head, Co. Wexford. The burrows are endichnial tubes orthogonal to bedding up to 15 cm long and c. 7 cm across. Their openings are elliptical with long axes parallel to the cleavage/bedding intersection lineation. The openings often have a raised rim with a central depression. The elliptical shape is due to a low tectonic strain (1:1.2) developed when cleavage and monoclinal folds formed. The strain has been removed from the burrow diameters and reveals a normally distributed range of values with means varying from locality to locality. Unstrained burrow openings reveal no systematic pattern of distribution indicative of colonial behaviour in the animals. Burrow morphology is broadly similar to Beaconites antarcticus, a trace fossil widely reported from the Old Red Sandstone. The burrows are dissimilar in detail principally in the absence of meniscus structure in the burrow fill. The sediments were deposited in ephemeral river systems on a proximal alluvial plain and the burrows occur in the upper parts of sheetflood sands. The burrows are tentatively interpreted as escape burrows of xiphosurids swept in and buried by the sheetflood event.

The Courceyan stratigraphy of the Pallaskenry Borehole, County Limerick, Ireland

AbstractThe Pallaskenry Borehole, Co. Limerick, Ireland provides an almost complete Courceyan (Dinantian) succession from Old Red Sandstone facies up to Waulsortian limestones. A revised lithostratigraphic‐al nomenclature for this succession is presented. Examination of the conodont and coral faunas in the borehole has enabled biozones to be defined which can be recognized throughout the Limerick Province. Biostratigraphical correlations are made with Courceyan successions at Hook Head, Co. Wexford, in the Mendip Hills and in Knap Farm Borehole in the Southwestern Province of Britain. Conodont taxa show a clear distinction betweeen the shelf faunas of the Limerick Province, Hook Head and eastern Mendip, and distal shelf faunas from south Cork, Knap Farm and Dinant, Belgium, which probably reflect their different palaeogeographical positions.Acknowledgements. The authors wish to express their thanks to Professor G. D. Sevastopulo, Drs. R. L. Austin, J. R. Nudds and P. Strogen and Mr. M. Mitchell for constructive criticism of the manuscript. We would also like to thank Dr. T. R. Reilly, Mr. C. McDermot and Dr. A. Sleeman of the Geological Survey of Ireland, and Dr. M. E. Philcox for fruitful discussion on the Iithostratig‐raphical nomenclature. G. LI. Jones was a Research Fellow at Trinity College, Dublin during the period of this work. He was funded through the Upper Palaeozoic Atlas of Ireland (UPAIR) Project, financed by the Department of Energy and administered through the Geological Survey of Ireland and Trinity College. He gratefully acknowledges the organization and supervision provided by Professors C. H. Holland and G. D. Sevastopulo and Dr. D. Naylor; and the assistance with conodont processing given by Ms. B. Thornbury. Thanks are also extended to Mr. J. Kennedy and Mr. P. Moffat for assistance with the diagrams.

Aspects of the sedimentology, palynology and palaeobotany of the Upper Devonian of southern Kerry Head, Co. Kerry, Ireland

AbstractThe uppermost 220 m of Upper Devonian sedimentary rocks of southern Kerry Head are described in terms of three lithofacies associations. Facies association 1 (about 49 per cent of succession) comprises fine to medium grained sandstones, with basal erosion surfaces and intraformational breccias, dominantly cross‐stratified, and usually displaying a multistorey character. They are interpreted as deposits of laterally migrating and aggrading single‐channel rivers, flowing in a southerly direction. Facies association 2 (43 per cent) comprises interbedded fine to very fine grained sandstones and siltstones, displaying a diversity of sedimentary structures, rapid lateral and vertical facies transitions, and occurring as broad sheets or channel‐filling sequences. They are interpreted as crevasse, levee, and channel‐fill deposits. Association 3 (8 per cent) is dominantly siltstone, with lenses and sheets of very fine sandstone, interpreted as the floodbasin deposits of a semi‐arid alluvial plain.Macrofloras and spores occurring in association 2 indicate: (1) major plants (woody seed ferns) grew in areas very close to palaeochannel margins; (2) a phytogeographic location within the Munster Basin comparable with Hook Head; and (3) a Late Devonian age for the succession.

Upper Devonian and Lower Carboniferous Miospore Assemblages from Hook Head, County Wexford, Ireland

Three successive miospore assemblages are described from the Upper Devonian and Lower Carboniferous strata of Hook Head in southeast Ireland. Their stratigraphic significance and position within the existing miospore zonation schemes of western Europe are discussed. Comparisons are made with Tournaisian microfloras described from eastern Canada. Twenty-two new species are erected, four new spore types are described, and one new combination is proposed. Upper Devonian and Lower Carboniferous miospore assemblages from Hook Head, County Wexford, Ireland INTRODUCTION AND STRATIGRAPHY The miospore assemblages described were obtained from samples of the Upper Old Red Sandstone facies, the overlying Porter's Gate Formation, and base of the Hook Head Formation of Hook Head, County Wexford, southeast Ireland. These sediments range from ?Famennian-Tournaisian to middle Tournaisian in age and represent a continuous transition from fluviatile to marine conditions. The present study was undertaken to investigate the stratigraphic distribution of miospores in this section and thereby enable the author to describe in detail the microfloral changes that had been observed during a preliminary investigation by Dolby (1970). The Old Red Sandstone succession is approximately 360 m. in thickness and consists of coarse conglomerates resting unconformably on Lower Palaeozoics and overlain by red sandstones, siltstones, and conglomerates. There follows a sequence of red and grey sandstones, and siltstones with occasional conglomerates and mudstones. This succession has not yet been fully described but has been subdivided by MacCarthy, Gardiner, and Horne (1971) and Gardiner and Horne (1973). There is no macropalaeontological evidence for the age of these sediments, but Dolby (1 970, p. 271, fig. 2) tentatively correlated a horizon approximately 11 5 m. below the top of the Old Red Sandstone with the Tnla-Tnlb boundary in Belgium. The strata overlying the Old Red Sandstone have recently been described by Sleeman et al. (1974) and is divided into the Porter's Gate Formation and the overlying Hook Head Formation. The Porter's Gate Formation consists of two members, the lower of which has been termed the Houseland Sandstone Member; the upper, the Lyraun Cove Shale Member. This scheme of stratigraphic subdivision has been adopted in the present study. Strata comprising the Porter's Gate Formation were considered by Smyth (1930) to be of K-Zone age in terms of Vaughan's (1905) coralbrachiopod zonation. The age of the formation based on conodont evidence was discussed by Sleeman et al. (1974), who closely compared faunas from the Lyraun Cove Shale Member with those recorded by Butler (1973) from the upper part of the Lower Limestone Shales at Maesbury in the eastern Mendips, England. Faunas from the Houseland Sandstone Member are similar to those obtained from the lower part of the Lower Limestone Shales in the same area. The strata referred to in this study are the basal metre of the Hook Head Formation, the Porter's Gate Formation, and the upper 99 m. of the Old Red Sandstone. micropaleontology, vol. 21, no. 4, pp. 393-419, pls. 1-7, october, 1975 393 This content downloaded from 207.46.13.179 on Tue, 18 Oct 2016 06:18:15 UTC All use subject to http://about.jstor.org/terms

New Irish Tournaisian Fenestellids

AbstractA new genus, Levifenestella, is erected, with L. maeve n.sp. from the Tournaisian of Co. Sligo, Ireland, as type species. A new species of Fenestella, F. polynodosa, from the same horizon and locality, is described. A Russian species, F. rossica Shulga-Nesterenko, is recorded from the Tournaisian of Hook Head, Co. Wexford.