Lias Group Research Articles

The influence of earthworks construction on porewater pressures in clays and mudstones of the Lias Group

Monitoring the changes in porewater pressure associated with the construction of earthworks can yield information on the stiffness and permeability of the ground, as well as how the natural groundwater regime might be impacted. This paper presents 3 years of porewater pressure measurements in weathered Lias Group mudstone, obtained from a trial cutting and a trial embankment constructed for the UK's High Speed Two (HS2) railway. The immediate changes in porewater pressure were small in relation to the changes in total stress imposed. This can be explained by the consolidation or swelling during the period of construction, combined with the sensitivity of very stiff clays and mudstones to a very small (0.5%) reduction in the degree of saturation. In the longer term, porewater pressures reduced across the site owing to the reduction in ground level at the trial cutting. Rates of porewater pressure change were accelerated by more permeable limestone within the ground profile reducing drainage path lengths. It was concluded that construction-induced porewater pressure changes may be smaller, and their rate of dissipation more rapid, in weathered clays and mudstones such as those of the Lias Group than in younger, more compressible clay deposits.

The Early Jurassic sequence of Lyme Regis, Dorset, England and its place in the history of geology and palaeontology

Abstract The cliffs and foreshore at Lyme Regis on the Dorset coast expose a sequence of Early Jurassic marine limestones and mudstones of the Blue Lias Formation and the overlying Charmouth Mudstone Formation, the lowest units of the Hettangian–Aalenian Lias Group. Known for its fossils since at least the mid-seventeenth century, this coastal section became famous in the early nineteenth century for the bones of ‘fossil crocodiles’. Many of the most significant discoveries were made by a family of fossil dealers whose best-known member was Mary Anning (1799–1847). Anning and her family recovered the first scientifically described ichthyosaurs, the first complete plesiosaur and the first British pterosaur to be identified. Anning's finds from Lyme Regis formed the basis of the pioneering palaeoenvironmental reconstruction Duria antiquior . Her geologist friends, some with close personal associations to the town, did much to publicize her discoveries and contribute to both her fame and that of the locality. This famous coastal section, with its important historical associations with a key period in the development of geology and the source of so many significant discoveries in the early nineteenth century, now lies within the Jurassic Coast UNESCO World Heritage Site.

Initial results of coring at Prees, Cheshire Basin, UK (ICDP JET project): towards an integrated stratigraphy, timescale, and Earth system understanding for the Early Jurassic

Abstract. Drilling for the International Continental Scientific Drilling Program (ICDP) Early Jurassic Earth System and Timescale project (JET) was undertaken between October 2020 and January 2021. The drill site is situated in a small-scale synformal basin of the latest Triassic to Early Jurassic age that formed above the major Permian–Triassic half-graben system of the Cheshire Basin. The borehole is located to recover an expanded and complete succession to complement the legacy core from the Llanbedr (Mochras Farm) borehole drilled through 1967–1969 on the edge of the Cardigan Bay Basin, North Wales. The overall aim of the project is to construct an astronomically calibrated integrated timescale for the Early Jurassic and to provide insights into the operation of the Early Jurassic Earth system. Core of Quaternary age cover and Early Jurassic mudstone was obtained from two shallow partially cored geotechnical holes (Prees 2A to 32.2 m below surface (m b.s.) and Prees 2B to 37.0 m b.s.) together with Early Jurassic and Late Triassic mudstone from the principal hole, Prees 2C, which was cored from 32.92 to 651.32 m (corrected core depth scale). Core recovery was 99.7 % for Prees 2C. The ages of the recovered stratigraphy range from the Late Triassic (probably Rhaetian) to the Early Jurassic, Early Pliensbachian (Ibex Ammonoid Chronozone). All ammonoid chronozones have been identified for the drilled Early Jurassic strata. The full lithological succession comprises the Branscombe Mudstone and Blue Anchor formations of the Mercia Mudstone Group, the Westbury and Lilstock formations of the Penarth Group, and the Redcar Mudstone Formation of the Lias Group. A distinct interval of siltstone is recognized within the Late Sinemurian of the Redcar Mudstone Formation, and the name “Prees Siltstone Member” is proposed. Depositional environments range from playa lake in the Late Triassic to distal offshore marine in the Early Jurassic. Initial datasets compiled from the core include radiography, natural gamma ray, density, magnetic susceptibility, and X-ray fluorescence (XRF). A full suite of downhole logs was also run. Intervals of organic carbon enrichment occur in the Rhaetian (Late Triassic) Westbury Formation and in the earliest Hettangian and earliest Pliensbachian strata of the Redcar Mudstone Formation, where up to 4 % total organic carbon (TOC) is recorded. Other parts of the succession are generally organic-lean, containing less than 1 % TOC. Carbon-isotope values from bulk organic matter have also been determined, initially at a resolution of ∼ 1 m, and these provide the basis for detailed correlation between the Prees 2 succession and adjacent boreholes and Global Stratotype Section and Point (GSSP) outcrops. Multiple complementary studies are currently underway and preliminary results promise an astronomically calibrated biostratigraphy, magnetostratigraphy, and chemostratigraphy for the combined Prees and Mochras successions as well as insights into the dynamics of background processes and major palaeo-environmental changes.

A new subsurface record of the Pliensbachian–Toarcian, Lower Jurassic, of Yorkshire

Here, we describe the upper Pliensbachian to middle Toarcian stratigraphy of the Dove's Nest borehole, which was drilled near Whitby, North Yorkshire, in 2013. The core represents a single, continuous vertical section through unweathered, immature Lower Jurassic sedimentary rocks. The thickness of the Lias Group formations in the Dove's Nest core is approximately the same as that exposed along the North Yorkshire coast between Hawsker Bottoms and Whitby. The studied succession consists of epeiric-neritic sediments and comprises cross-laminated very fine sandstones, (oolitic) ironstones, and argillaceous mudstones. Dark argillaceous mudstone is the dominant lithology. These sediments were deposited in the Cleveland Basin, a more subsident area of an epeiric sea, the Laurasian Sea. We present a set of geochemical data that includes organic carbon isotope ratios ( δ 13 C org ) and total organic carbon (TOC). The δ 13 C org record contains a negative excursion across the Pliensbachian–Toarcian boundary and another in the lower Toarcian that corresponds to the Toarcian Oceanic Anoxic Event (T-OAE). Below the T-OAE negative excursion, δ 13 C org values are less 13 C-depleted than above it. We find no evidence of a long-term δ 13 C org positive excursion. TOC values below the T-OAE negative excursion are lower than above it. Sedimentary evidence suggests that, during much of the Pliensbachian–Toarcian interval, the seafloor of the Cleveland Basin was above storm wave-base and that storm-driven bottom currents were responsible for much sediment erosion, transport, and redeposition during the interval of oceanic anoxia. The abrupt shifts observed in the δ 13 C org record (lower Toarcian) are likely to reflect the impact of erosion by storms on the morphology of the δ 13 C record of the T-OAE. Supplementary material: stratigraphic and geochemical data [organic carbon isotope ratios ( δ 13 C org ) and total organic carbon (TOC)] are available at https://doi.org/10.6084/m9.figshare.c.6154436

The influence of weathering on index properties and undrained shear strength for the Charmouth Mudstone Formation of the Lias Group at a site near Banbury, Oxfordshire, UK

The Lias outcrop extends continuously from Dorset to Yorkshire in England, with outlying areas in Somerset and Wales. It underlies the transport routes between a number of major UK cities. Understanding the material properties of the Lias Group is therefore important for infrastructure construction and maintenance across England and Wales. This study examines the influence of weathering on the engineering properties of the Charmouth Mudstone Formation (Lias Group) in light of recent developments in ground-investigation practice including: (i) the use of modern visual weathering classifications for soils and rocks; and (ii) the availability of large ground-investigation datasets from the construction of the High Speed Two (HS2) railway. The variability in the undrained shear strength data was consistent with the moisture content, liquidity index and plasticity index of the samples, but they were poorer indicators than shown in previous studies. The visually-assessed weathering class and the depth below ground level were found to be more useful indicators of the undrained shear strength of the clay and mudstone samples of the Charmouth Mudstone Formation. Supplementary material: Dataset for the Undrained Shear Strength and Index Properties of Charmouth Mudstone Formation Samples Excavated Near Banbury, Oxfordshire, UK, is available from the University of Bath Research Data Archive at https://researchdata.bath.ac.uk/id/eprint/1012

Uppermost Triassic to Lower Jurassic stratigraphy in the Lough Foyle Basin of County Londonderry, Northern Ireland

The Lough Foyle Basin is a half-graben that straddles the border between Northern Ireland and the Republic of Ireland and contains sediments that range in age from Lower Carboniferous to Holocene. The basin’s post-rift succession is represented by sediments of the Penarth Group and Lias Group. The lithostratigraphy and biostratigraphy of that interval are revised using new borehole material and existing outcrop. Palaeontological data provide a chronostratigraphic framework and aid palaeoenvironmental interpretations. Foraminifera, ostracods, palynomorphs indicate a nearshore, marginal marine depositional setting throughout much of the Rhaetian with a more marine, shelf and nearshore depositional setting for the Lias Group. The Penarth Group succession is similar to that elsewhere in Northern Ireland but the Lias Group (Waterloo Mudstone Formation) differs in that five distinct members can be recognised (Clooney Mudstone, Drummans Siltstone, Gortmore Mudstone, Tircreven Sandstone and Ballyleighery Mudstone), four of which are newly described. The deltaic and shelf sandstones of the Tircreven Sandstone Member are the only such examples preserved in the Jurassic strata of Northern Ireland and are some of the oldest in the Jurassic of the UK and Ireland, providing evidence of the proximity of the nearby Irish Landmass and representing a useful comparison for Early Jurassic sandstone reservoirs in offshore basins.

Ammonites from the Lias Group (Lower Jurassic, Sinemurian and Pliensbachian) of White Park Bay, Co. Antrim, Northern Ireland

Northern Ireland's Jurassic succession has received relatively little detailed investigation. Late Sinemurian and early Pliensbachian strata are present in parts of north Antrim but they are poorly exposed at outcrop and have been penetrated by just a single borehole, at Portmore, in which parts of the succession are missing. Collecting from White Park Bay over more than two decades, augmented by examination of museum material, has established the presence within the Rathlin (North Antrim) Basin of ammonite zones and subzones additional to those proven in the Portmore Borehole. This suggests that parts of the Sinemurian and Pliensbachian stages, from the Obtusum Zone through to the Davoei Zone, and possibly even higher, may be preserved in onshore or nearshore parts of the basin. Despite the generally poor exposure, the material recovered encompasses more than 40 ammonite species, including several taxa that are poorly represented elsewhere in the UK, of which two, Vicininodiceras dalriatense sp. nov. and Cheltonia howarthi sp. nov., are previously undescribed.

Palaeoecological patterns of change in marine invertebrate faunas across the End-Triassic mass extinction event: Evidence from Larne, Northern Ireland

The End-Triassic mass extinction event [ETE] (201.5 Ma) marks a drastic turnover and loss of >50% of marine biodiversity. Suggested environmental factors include extreme climate change and global carbon-cycle perturbations linked to Central Atlantic Magmatic Province (CAMP) volcanism. Considerable attention has been paid to disentangling the causes and selectivity of the ETE, whilst downplaying the patterns of change in the structure and functioning of marine paleofauna. Here we provide detailed quantitative information from across the Triassic-Jurassic boundary at Waterloo Bay, Larne, Northern Ireland, to describe patterns of changes in different palaeoecological parameters across the ETE. The analysis was based on abundance data of species sampled from approximately 1 m intervals through the sequence. Dominance and richness were estimated using rarefaction techniques and β-diversity index, and distinctness diversity indices were calculated. Changes in species composition were evaluated by multivariate analysis (nMDS, ANOMSIM and SIMPER). Rank abundance models were fitted, and functional diversity were estimated based on an ecospace model, applied to each sampled unit to detect changes in structure and ecological complexity. Across the ETE three distinctive states were identified: the pre-extinction state (Westbury Formation), characterised by an assemblage with high species richness and ecological redundancy, and with low taxonomic variation and functional diversity. The extinction state (Cotham and Langport members) represents a shift of the marine ecosystem, where >70% marine species disappears decreasing the ecosystems functioning the marine ecosystem around 80%. The recovery state (Lias Group), commencing some ~150 ky after the extinction, with ecologically complex assemblages as new taxa colonised, increasing variation in taxonomic distinctness and new contributing ecological traits and functional richness through the Hettangian. The palaeoecological patterns described here are robust enough to discount possible facies effects, but more important, is consistent with other studies reported globally, and demonstrates that the ecological signals detected in this study are real.

Fossil echinoderms from the Triassic and Jurassic of Ireland

An overview is provided of fossil echinoderm taxa recovered from the Jurassic (Lias Group) and Triassic (Penarth Group) of Ireland. Despite limited outcrop and generally poor exposure, at least 12 species are recorded (6 crinoids, 2 echinoids, 3 ophiuroids and one asteroid), with significant new material recovered from an early Hettangian lagerstätte. The crinoid Isocrinus angulatus (Fraas, 1858), omitted from an earlier Palaeontographical Society Monograph on Lower Jurassic crinoids, is described based on articulated material.

First dinosaur remains from Ireland

Several specimens from the Lias Group (Lower Jurassic) of Northern Ireland have been suspected as dinosaurian in origin. Bone histology and morphology demonstrates that two of these, both from the same locality in Co. Antrim, demonstrably are from dinosaurs. We interpret one as the proximal end of the left femur of a basal thyreophoran ornithischian, and tentatively assign it to cf. Scelidosaurus. The other is the proximal part of the left tibia of an indeterminate neotheropod, perhaps a member of the averostran-line similar to Sarcosaurus, or a megalosauroid. These are the first dinosaur remains reported from anywhere in Ireland and some of the most westerly in Europe, and they are among only a small number of dinosaurs known from the Hettangian Stage. Two additional specimens are no longer considered to be from dinosaurs. We interpret one as a surangular or mandible fragment from a large marine reptile, perhaps an ichthyosaur or pliosaur; the other is a polygonal fragment of Paleocene basalt.

A small theropod dinosaur from the Lower Jurassic Lias Group of Charmouth, Dorset

Terrestrial reptile remains are rare in Early Jurassic deposits from the UK but include important records of early dinosaurs and pterosaurs. Here we report an isolated limb bone from the Charmouth Mudstone Formation (upper Sinemurian) of Charmouth, Dorset that was previously misidentified as a referred specimen of the pterosaur Dimorphodon macronyx. Comparisons with other Early Jurassic tetrapods indicate that this element is the fibula of a neotheropod dinosaur, representing one of only a handful of theropod remains from the Lias Group. Although the material is limited the fibula is distinct from other penecontemporaneous European theropods and might represent a new – though currently undiagnosable – taxon. This, alongside other isolated discoveries, indicates that there might have been a higher diversity of theropod taxa in the Early Jurassic of Europe than is generally appreciated.

Lower Jurassic (Hettangian–Pliensbachian) microfossil biostratigraphy of the Ballinlea-1 well, Rathlin Basin, Northern Ireland, United Kingdom

The thickest section of Early Jurassic strata known from onshore Ireland (total Jurassic thickness 566 m) is reported from the Ballinlea-1 well (Rathlin Basin) situated on the north coast of Northern Ireland. A biostratigraphical and palaeoenvironmental assessment is presented for this section largely based on calcareous benthic microfossils (foraminifera and ostracods). The Early Jurassic Waterloo Mudstone Formation (Lias Group) of Northern Ireland has previously received little micropalaeontological attention, therefore this work provides an opportunity to enhance palaeogeographic and palaeoenvironmental understanding for the Early Jurassic of the province, and this paper illustrates the key microfossil taxa of this age from Ireland for the first time. The records, based on ditch-cuttings samples, demonstrate a stratigraphical range from Hettangian to Early Pliensbachian, consistent with other wells and boreholes in this basin. The assemblage compositions are comparable to those elsewhere in the European boreal Atlantic realm. Hettangian to earliest Sinemurian microfossil assemblages are generally of low diversity and are numerically dominated by metacopid ostracods with occasional influxes of foraminifera. Gradually, foraminiferal abundance (often dominated by species of the Lagenida) come to exceed those of the ostracods in the Early Sinemurian reaching their greatest diversity in the Late Sinemurian. The sediments are considered to represent an inner to mid-shelf environment throughout while the record thickness for this region indicates ongoing syn-sedimentary fault movement along the basin margins within this period.

Stratigraphy, palaeoenvironments and geochemistry across the Triassic–Jurassic boundary transition at Carnduff, County Antrim, Northern Ireland

The latest Triassic to earliest Jurassic transition has been widely studied due the occurrence of a major global extinction associated with a global hyperthermal event in this interval. Furthermore, a number of distinct geochemical events in the global carbon cycle can be recognised in the stable-isotope record across this boundary interval at many localities. Two fully-cored boreholes from East Antrim in Northern Ireland (Carnduff-1 and Carnduff-2) have penetrated sediments of latest Triassic to Early Jurassic age (Rhaetian to Early Sinemurian). Ammonites, foraminifera, ostracods and palynomorphs provide a robust chronology as well as insights to palaeoenvironmental conditions during this period. The sedimentary and palynological evidence support a largely marginal-marine setting for the sediments of the Triassic Penarth Group while a range of palaeontological evidence shows that the Early Jurassic Waterloo Mudstone Formation represents shallow-marine, shelf conditions that represent generally well-oxygenated bottom waters, with little evidence for dysoxia. Detailed ammonite biostratigraphy (ammonites first occur about 7.5 m up from the base of the Lias Group) indicates that the cores represent largely continuous sedimentation through the Hettangian and earliest Sinemurian (to Turneri Chronozone, Birchi Subchronozone). Stable-isotope analysis of both carbonate and organic carbon show a distinct carbon isotope excursion (CIE) in both fractions through the Cotham and Langport members (Lilstock Formation, Penarth Group, latest Triassic) which are considered to correlate with the distinctive ‘Initial’ CIE witnessed in SW England and probably the GSSP and other sites across the world.

Uppermost Triassic to Lower Jurassic sediments of the island of Ireland and its surrounding basins

The uppermost Triassic to Lower Jurassic interval has not been extensively studied across the island of Ireland. This paper seeks to redress that situation and presents a synthesis of records of the uppermost Triassic and Lower Jurassic from both onshore and offshore basins as well as describing the sedimentological characteristics of the main lithostratigraphical units encountered. Existing data have been supplemented with a re-examination and logging of some outcrops and the integration of data from recent hydrocarbon exploration wells and boreholes. The Late Triassic Penarth Group and Early Jurassic Lias Group can be recognised across the Republic of Ireland and Northern Ireland. In some onshore basins, almost 600 m of strata are recorded, however in offshore basins thicknesses in excess of two kilometres for the Lower Jurassic have now been recognised, although little detailed information is currently available. The transition from the Triassic to the Jurassic was a period of marked global sea-level rise and climatic change (warming) and this is reflected in the lithostratigraphical record of these sediments in the basins of Northern Ireland and offshore basins of the Republic of Ireland. In general, the sediments of this interval are thicker than those in Great Britain and have potential for detailed study of climatic and sea-level fluctuation.

A rare and unusual trace fossil from the Lower Jurassic (Lias Group) of Ketton, East Midlands, UK

The top of the Whitby Mudstone Formation (Lias Group, Toarcian, Bifrons ammonite Zone) is exposed low in the geological Site of Special Scientific Interest at Ketton Quarry, East Midlands. A rare burrow of Fustiglyphus annulatus Vialov from this part of the succession, not reported from the Whitby Mudstone Formation hitherto, was collected from float. In the dull brown mudrock, the burrow has a contrasting fill of grey sandstone. The shaft of the burrow is cylindrical, with two broad, bell-shaped chambers. Fustiglyphus annulatus is found in deeper water deposits in the post-Palaeozoic, so its occurrence in the Whitby Mudstone Formation, an offshore shelf deposit, is not unexpected. However, orientation is equivocal; the burrow was either angled at 45° to bedding, based on the evidence of an associated Arenicolites isp., or parallel to bedding, its common configuration.

The spatial distribution and geochemical variation of fault and fracture hosted calcite and gypsum cements in the eastern Bristol Channel Basin

Abstract The spatial distribution and geochemical variation of fault- and fracture-hosted cements can be used to reconstruct the evolution and migration of pore fluids in sedimentary basins. Geochemical data, from stable oxygen and carbon isotope and strontium isotope analyses, of calcite and gypsum cements provide valuable insights into the source of pore fluids and their evolution in the eastern Bristol Channel Basin. Overall, at both an outcrop-scale and a basin-scale there were no observable relationships between the dip angle and direction of fractures with the oxygen and carbon isotopic composition of calcite cements, indicating that the movement and distribution of fluids in fractures is not controlled by the orientation of fracture opening. Radiogenic strontium isotopic compositions of calcite and gypsum cements indicate at least two different mineralising fluid compositions that are strongly controlled by the lithologies (fossiliferous limestones and shales, and marls with gypsum nodules, respectively) in which they occur. These fluids originated as connate pore fluids that were altered during the diagenesis of their host lithologies. Mineralising fluids within the Lower Jurassic Lias Group are characterised by enriched oxygen and strontium isotopic compositions and relatively depleted carbon isotopic compositions, associated with the alteration of labile minerals and carbonaceous fossils. Mineralising fluids within the Triassic Mercia Mudstone Group have enriched strontium isotopic compositions as a result of the interaction of fluids with evaporitic intervals. The mineralising fluids were redistributed through migration along faults and their associated damage zones. This study highlights the importance of integrating a range of geochemical analyses when attempting to understand the source of fluids and their evolution through time. The findings from this study can also be applied to nearby petroleum producing basins, e.g. the Wessex Basin, where equivalent rocks are economically significant source rocks and caprocks and have experienced similar structural histories.

Mesozoic Holcoptera (Coleoptera: Coptoclavidae) from England and the United States

The impact of mass extinctions on insect evolution is debated, so investigating taxa that span a crisis is important for understanding such large-scale environmental perturbations. The beetle genus Holcoptera has been found in deposits from the Late Triassic: Norian to the Early Jurassic: Sinemurian of England and the United States, and possibly Italy. Historical collections of Rev. P.B. Brodie and J.F. Jackson were re-examined and the ages of British localities reviewed, US collections were re-interpreted, and new material from the Dorset Coast was considered. Holcoptera schlotheimi and Holcoptera confluens are synonymised based on morphological similarities; Holcoptera giebeli remains distinct and a new complete specimen confirms the placement of this genus in the family Coptoclavidae. Three new species are described: Holcoptera pigmentatus sp. nov. from the Penarth Group of Warwickshire, Holcoptera alisonae sp. nov. (based on the rejected neotype of H. schlotheimi) from the Lower Lias of Dorset and Holcoptera solitensis sp. nov. from the Newark Supergroup of Virginia. H. schlotheimi and H. giebeli are known from the Late Triassic Penarth Group and Early Jurassic Lias Group and so survived the end-Triassic extinction, whereas H. alisonae and H. pigmentatus are only known from the Lias Group. H. solentensis is the oldest described species in this genus and is not known from any other locality.

Landslide characterization using P- and S-wave seismic refraction tomography — The importance of elastic moduli

In the broad spectrum of natural hazards, landslides in particular are capable of changing the landscape and causing significant human and economic losses. Detailed site investigations form an important component in the landslide risk mitigation and disaster risk reduction process. These investigations usually rely on surface observations, discrete sampling of the subsurface, and laboratory testing to examine properties that are deemed representative of entire slopes. Often this requires extensive interpolations and results in large uncertainties. To compliment and extend these approaches, we present a study from an active landslide in a Lias Group clay slope, North Yorkshire, UK, examining combined P- and S-wave seismic refraction tomography (SRT) as a means of providing subsurface volumetric imaging of geotechnical proxies.The distributions of seismic wave velocities determined from SRT at the study site indicated zones with higher porosity and fissure density that are interpreted to represent the extent and depth of mass movements and weathered bedrock zones. Distinguishing the lithological units was facilitated by deriving the Poisson's ratio from the SRT data as saturated clay and partially saturated sandy silts showed distinctively different Poisson's ratios. Shear and Young's moduli derived from the SRT data revealed the weak nature of the materials in active parts of the landslide (i.e. 25kPa and 100kPa respectively). The SRT results are consistent with intrusive (i.e. cone penetration tests), laboratory, and additional geoelectrical data from this site. This study shows that SRT forms a cost-effective method that can significantly reduce uncertainties in the conceptual ground model of geotechnical and hydrological conditions that govern landslide dynamics.

Effects of high-impact aerobics vs. low-impact aerobics and strength training in overweight and obese women

Regular exercise is one of the factors determining weight reduction and fat loss, and at the same time it is associated with important health benefits. The purpose of this study was to compare the effects of two different modalities of exercise on changes in body composition, physical fitness, and CVR factors in healthy overweight and obese women. Thirty-two women were randomly assigned in 2 groups: a high-impact aerobics group (HIA, N.=16) and a low-impact aerobics combined with a strength training program group (LIAS, N.=16). Body weight (BW), body composition, aerobic fitness (AF), speed and agility, vertical-jump distance (VJ), abdominal muscle endurance (AME), the flexibility of the lower back and hamstrings, heart rate (HR), systolic (SBP) and diastolic blood pressure (DBP), total cholesterol (TC), triglyceride (TG), HDL-c, LDL-c, apolipoprotein A-I (Apo A-I) and B (Apo B) were measured at baseline and at the end of the training period. A significant decrease was noted in all anthropometric variables excepting fat-free mass (FFM) which increased in LIAS group (P<0.05). Comparisons between groups noted significant differences in favor of HIA group in BW, fat percentage and FM, and in favor of LIAS group in FFM (P<0.05 for all). DBP, HR, TC, LDL-c, TG, and Apo B significantly decreased, and HDL-c and Apo A-I significantly increased in both groups. No significant modifications were noted in SBP and glucose concentrations. Significant improvements in all physical fitness components were also noted in HIA group (P<0.05), however, only the AF, VJ, AME, and the flexibility were improved in LIAS group (P<0.01). Comparison between groups reported that values related to VJ and AME were higher in LIAS compared to HIA group (P<0.01). Our findings noted that a 24-week of HIA or LIAS training improved body composition, physical fitness and CVR factors in overweight and obese women. Nevertheless, the use of each training method remains tributary to wished effects. In fact, HIA training method is more effective in body weight reduction and fat loss, however, LIAS training method is more appropriate when the improvement of FFM, aerobic fitness and muscle strength is claimed.

The first definitive occurrence of Ichthyosaurus and Temnodontosaurus (Reptilia: Ichthyosauria) in Nottinghamshire, England and a review of ichthyosaur specimens from the county

The occurrence of ichthyosaurs from Nottinghamshire is poorly documented. Here, we report on at least 67 specimens from museum and university collections. The specimens range from isolated elements to nearly complete skeletons. Preservation varies, but some are three-dimensional. The identification of both Ichthyosaurus and Temnodontosaurus in the county adds additional localities for the occurrence of those genera. Nottinghamshire is one of only a few counties to have yielded a fairly substantial number of ichthyosaur specimens. They are from localities in the Upper Triassic (Penarth Group) and Lower Jurassic (Lower Lias Group) that can no longer be accessed.