Clee Hill Research Articles

A baptism by fire: fossil charcoal from eastern Euramerica reveals the earliest (Homerian) terrestrial biota evolved in a flammable world

Charred fossils from the Wenlock (Wales) and Ludlow (Poland) are evidence of the earliest wildfires to date, showing that this phenomenon was contemporaneous with the earliest records of land plant macrofossils. These data indicate that fires began to influence Earth system processes alongside those wrought by the advent of an embryophytic terrestrial flora. By the mid-Silurian, fires affected atmospheric composition, sedimentary systems, carbon and nutrient cycling, landscape diversity, community composition and species interactions. As global heating alters wildfire regimes, greater recognition is being given to fires and their ecosystem impacts, a relationship we now know extends back >430 myr. Here we document the taxonomic composition of charred phytoclasts, evidence of wildfire activity, from two discrete Silurian localities: the Pen-y-lan Mudstone, Rumney, Wales, and the Winnica Formation, Holy Cross Mountains, Poland. Nematophytes dominate each mesofossil assemblage and quantitative reflectance data indicate generally low-temperature fires at both sites, but with locally intense conditions. These and other Silurian assemblages, herein documented as bearing charcoal, are used to evaluate the systematics, fuel load and burn temperatures of these earliest wildfires. We propose a diagrammatic reconstruction to explain the seeming disparity between the diminutive size of the embryophytic biota and the highest temperatures (>700°C) recorded in these charcoals. Supplementary material : Raw mean random reflectance ( R o %) data from Rumney Borehole, Winnica, Ludford Lane and North Brown Clee Hill, sorted by both locality and morphotype, are available at https://doi.org/10.6084/m9.figshare.c.6179309

Reconstructing the Lower Devonian (Lochkovian) vegetation from the Anglo-Welsh Basin: Two spore masses containing Emphanisporites McGregor spores

In situ spores have gone some way towards harmonising the prominent disparity between the Early Devonian dispersed spore and megafossil records, greatly advancing but often challenging our understanding of early vegetation. Here, we investigate an elongate and a discoidal spore mass, yielding Emphanisporites epicautus Richardson and Lister and Emphanisporites sp. respectively from the early (not earliest) Lochkovian (Lower micrornatus-newportensis spore assemblage biozone) of the Ross-Tewkesbury Spur (M50) motorway section in the Anglo-Welsh Basin, UK. We explore their morphology and spore wall ultrastructure using SEM and TEM. A paucity of useful phylogenetic characters precludes formal identification or description of the parent plants but a relationship to the rhyniophytes is hypothesised. A dearth of vascular tissues, however, necessitates their placement amongst the rhyniophytoids. Both the sporangial morphology and spore wall ultrastructure differs between the specimens, distancing them from each other and from other Emphanisporites species. While similarities exist, no unequivocal relationships with contemporaneous or extant taxa, or indeed lineages, can be made using sporangial morphology or spore wall architecture. These differences lend further support to deliberations that the ‘emphanoid’ condition was a consequence of convergent evolution. Using the dispersed spore record we explore the paleoecology of the plants, which points towards them being minor components of the vegetation, restricted to areas away from river catchment. This interpretation is redolent of the middle Lochkovian cf. Horneophyton sp. (E. cf. micrornatus parent plant) from North Brown Clee Hill, but that plant may have been restricted to a more specialised niche. What characterised the niches of these plants is uncertain, but they may have been ephemerally water stressed, perhaps hinting at a moisture sensing function for the ‘emphanoid’ spore structure.

Stem chondrichthyan microfossils from the Lower Old Red Sandstone of the Welsh Borderland

Placoid and polyodontode scales of stem chondrichthyans have been found in the early Lochkovian “Ditton Group” of the Brown Clee Hill district, Shropshire, England and at Talgarth, south Wales. One of the forms is assigned to a new species of Altholepis Karatajūtė-Talimaa, 1997, a genus already recognised from Lochkovian shallow marine deposits in Celtiberia, Spain and the Northwest Territories, Canada as well as the type locality in Podolia, Ukraine. Altholepis salopensis sp. nov. is based on small polyodontode scales with typically three to eight high odontodes; the scale form was previously considered to belong to acanthodian “ Nostolepis ” robusta (Brotzen, 1934). The structure of other scales formerly assigned to “ Nostolepis ” robusta has led us to erect a new genus Jolepis for this scale form, which differs from Altholepis in lacking an ordered layout of odontodes . Jolepis robusta (Brotzen, 1934), originally (and possibly still) considered to be an acanthodian, is also known from the Baltic countries, Russia, and northern Germany (ex erratic limestones). Scales of acanthodian Parexus recurvus Agassiz, 1845, and/or possibly from the stem chondrichthyan Seretolepis elegans Karatajūtė-Talimaa, 1968 (scales of these two taxa are barely distinguishable), and of stem chondrichthyan Polymerolepis whitei Karatajūtė-Talimaa, 1968 are also present. Altholepis , Jolepis gen. nov., Seretolepis Karatajūtė-Talimaa, 1968 and Polymerolepis Karatajūtė-Talimaa, 1968 are found in marine deposits elsewhere; the British occurrence of these taxa adds to the debate on the sedimentological origins of the Lower Old Red Sandstone deposits in the Welsh Borderland. The geographic range of several early sharks is now known to extend around the Old Red Sandstone continent and beyond.

Progress in reconstructing vegetation on the Old Red Sandstone Continent: two Emphanisporites producers from the Lochkovian sequence of the Welsh Borderland

Abstract Small coalified fossils (mesofossils) have yielded new insights into vegetation of the Old Red Sandstone Continent in early Devonian times. Particularly useful are those containing spores that can be placed in dispersed spore taxa, although patinate and emphanoid spores have not hitherto been found in situ. Emphanisporites cf. micrornatus Richardson & Lister is described in a bifurcating cylindrical sporangium preserved as a cuticular sheath. A terminal dehiscence feature is compared with that in Horneophyton . The sporangium is encased in amorphous detritus with some tubular fragments. Similar associations occur on other sporangia, e.g. Tortilicaulis and axes at this North Brown Clee Hill locality, and they are interpreted as remains of a microbial or fungal film. Fragmentary cuticles, interpreted as isolated sporangial valves, bear an undescribed species of Emphanisporites with fine interdigitating proximal muri and laevigate distal surfaces referred to Emphanisporites sp. A Richardson & Lister. Analysis of dispersed spore assemblages from the locality and others in the Welsh Borderland indicate that the two emphanoid taxa were not common components of the spore ‘rain’. This evidence, coupled with the dearth of mesofossils of the producers, suggests that the plants grew at the upper reaches of the drainage basin of the river that deposited the sediment, although the paucity of sporangia may also be attributed to their low fossilization potential.

Exceptional preservation in Lower Devonian coalified fossils from the Welsh Borderland: a new genus based on reniform sporangia lacking thickened borders

Reniform sporangia, comprising two equal valves and containing retusoid spores, recovered from Lower Old Red Sandstone strata of Devonian age (micrornatus-newportensis Spore Biozone: lower Gedinnian lower Lochkovian) on North Brown Clee Hill in the Welsh Borderland are placed in Resilitheca salopensis gen. et sp. nov. Conventional compression fossils from Targrove, Ludlow of fertile axes showing isotomous branching with limited overtopping are considered conspecific because the terminal reniform sporangia contain the same spores. Spore ultrastructure is described using scanning and transmission electron microscopy. Sections show faint traces of lamellae. Particles associated with spores and sporangium wall are compared with the globules of pteridophytes and Ubisch bodies of angiosperms, and related to the development of the sporangium. The new plants are compared with Cooksonia caledonica Edwards known only from impressions, and with Renalia Gensel showing far more pronounced pseudomonopodial branching.

Exceptional preservation in Lower Devonian coalified fossils from the Welsh Borderland: a new genus based on reniform sporangia lacking thickened borders

Reniform sporangia, comprising two equal valves and containing retusoid spores, recovered from Lower Old Red Sandstone strata of Devonian age (micrornatus-newportensisSpore Biozone: lower Gedinnian ± lower Lochkovian) on North Brown Clee Hill in the Welsh Borderland are placed inResilitheca salopensisgen.etsp. nov.Conventional compression fossils from Targrove, Ludlow of fertile axes showing isotomous branching with limited overtopping are considered conspecific because the terminal reniform sporangia contain the same spores. Spore ultrastructure is described using scanning and transmission electron microscopy. Sections show faint traces of lamellae. Particles associated with spores and sporangium wall are compared with the globules of pteridophytes and Ubisch bodies of angiosperms, and related to the development of the sporangium. The new plants are compared withCooksonia caledonicaEdwards known only from impressions, and withRenaliaGensel showing far more pronounced pseudomonopodial branching.

Opencast coal mining: a unique opportunity for Clee Hill Quarry

Abstract Clee Hill Quarry is an active hardstone (dolerite) quarry located 5 miles to the east of Ludlow, Shropshire. The quarry is in Carboniferous Coal Measures which have been intruded by a thick ( c. 60m) conformable fine-grained olivine-dolerite sill. The whole sequence is now folded into a broad synclinal structure and is extensively faulted. The area is blanketed by glacial deposits, 2–12m thick. Historically, quarrying operations have been closely allied to the geological structure being confined to the margins of the syncline where the dolerite is devoid of overlying Coal Measures. In 1973 a programme was undertaken to assess the viability of using Coal Measures material for the production of lightweight aggregate. This programme was initiated because virtually all remaining, albeit substantial, planned reserves of dolerite were overlain by considerable thicknesses of Coal Measures and glacial deposits. While initial results from a technical viewpoint were encouraging, the project was abandoned for commercial reasons. The Coal Measures sequence overlying the dolerite sill comprises in excess of 30 m of mudstones, siltstones and sandstones as well as four recognized coal seams. Piecemeal mining of this coal had taken place on the Clee Hills for centuries, and in the area for future quarrying abundant evidence was available at surface of former bell-pit workings. In the early 1980s a decision was taken to evaluate the coal deposits at Clee Hill Quarry. The area for detailed assessment was defined using existing borehole data and evidence from old workings identified from site survey and aerial photographs. Exploration in two separate phases comprised the drilling of 44 open holes with spot coring and borehole geophysical logging. Coal quality was determined by analysing all relevant borehole core samples. Although coal reserve estimates assumed a high degree of past shallow mining activity, the economic viability of working the coal seams by opencast methods was established. In 1986 a planning application was submitted to Shropshire County Council to work and remove all coal overlying the dolerite, over a 3 year period. The proposal would allow exploitation of a valuable mineral asset, release substantial reserves of hardstone (dolerite) and allow restoration at an early date of large areas of former mining and quarrying dereliction. Planning permission was obtained in August 1988. Negotiations with the Opencast Executive of British Coal culminated in the granting of a licence to work both British Coal (vested) and ARC (alienated) coal. Coal mining was commenced in October 1988. Predictions of seam thickness and faulting were consistently accurate and vindicated the site investigation programme. In two aspects more detailed/accurate information would have been useful. Firstly, with regard to coal quality, borehole core samples did not accurately reflect in situ moisture content. Secondly, the extent of old workings in the upper coal seams was significantly overestimated. Neither aspect significantly affected the viability of the project. The mining phase including the major restoration works was completed in July 1992.

Palynological evidence for an early Namurian age of the Cornbrook Sandstone Formation, Clee Hill, Shropshire

SUMMARY The formational name Cornbrook Sandstone has been applied to a variable succession of conglomerates and coarse-grained sandstones, with thin mudstone and coal intercalations, which occurs between the Carboniferous Limestone (Dinantian) and Coal Measures (Westphalian) in the Clee Hills area of Shropshire. Previous biostratigraphical investigations have proved inconclusive, suggested ages ranging from Tournaisian to Westphalian B. Palynological investigations on material from surface exposures and from three cored shallow boreholes, which penetrated most of the Cornbrook Sandstone sequence together with part of the underlying Carboniferous Limestone, provide new evidence for the age of the formation. Well preserved miospore assemblages indicate an early Namurian (Pendleian-Arnsbergian) age. The palynological evidence suggests that the base of the Cornbrook Sandstone is younger than the base of the Drybrook Sandstone of Gloucestershire, which exhibits broad similarities in tectonic and depositional settings. The two sandstones may, therefore, represent unrelated sand bodies, located north and south of St George’s Land. Alternatively, if they represent remnants of a more extensive deposit, its base may have been diachronous, becoming younger to the north.

Miospores, correlation and age of some Scottish Lower Old Red Sandstone sediments from the Strathmore region (Fife and Angus)

Abstract. The age of some Lower Old Red Sandstone sediments (Arbuthnott Group) is reassessed and confirmed as Lower Devonian (lower Gedinnian) on the basis of a reinvestigation of spore assemblages. The data upon which this age assessment is based are provided by recent palynological researches in the Welsh Borderland, the type area of the Gedinnian (Belgium), and the graptolite-bearing parastratotype for the Silurian-Devonian boundary (Podolia). Samples from the Arbuthnott Group at Wormit (Fife), associated with rocks dated as 407± 6 Ma by Thirlwall (1983) and regarded by him as Silurian, have yielded miospore assemblages of early but not earliest Devonian when compared with the Podolian Silurian-Devonian sequence. Samples throughout the sequence of the Arbuthnott Group as exposed in Angus and Fife have yielded miospores. These assemblages, occurring at levels above and below the Wormit samples, are all of lower Gedinnian age. The whole of the spore-bearing succession of the Arbuthnott Group, which is about 1,800 m thick, belongs to the micrornatus-newportensis Zone (lower and middle subzones) and is equivalent to part of the lower Ditton Group of Brown Clee Hill (Shropshire) of 20 to 30 m in thickness. There is no critical palaeontological evidence for age in the strata associated with the Arbuthnott Group, neither in the underlying Dunnottar and Crawton Groups nor in the overlying Garvock Group so the exact position of the Silurian-Devonian and Gedinnian-Siegenian boundaries is uncertain. A new spore Anteturma, namely Cryptosporites, is proposed. Qualisaspora fragilis gen. et sp. nov. is described herein and appears to have potential as an index fossil for the lower Dittonian of the British Isles. Some regional differences also occur as ?Dibolisporites sp. A and ?Samarisporites sp. A occur in beds dated as lower Gedinnian in Sotland whereas spores of similar sculpture and structure are present higher in the Anglo-Welsh sequence in beds dated as lower Siegenian.

HIGH FARMING IN SHROPSHIRE 1845–1870

AbstractGeographically Shropshire partakes both of the nature of Wales and of England. In its physiographical and geological structure the west and south of the county represent an eastern extension of Wales, and its rocks of Palaeozoic age extend from the Uriconian and pre-Cambrian through to the Devonian of the Clee Hill Plateau. North of the river Severn the solid geology is submerged beneath a diverse cover of glacial till and drift and of post-glacial deposits. The two parts differ also in respect of physical relief and much of south Shropshire is ove 800 feet above sea level (244m) and most of north Shropshire below 200 feet (61m). As precipitation is largely cyclonic in origin and orographic in incidence, the south and west are far wetter than the lower ground of north Shropshire.

The structure of the Swansea Valley Disturbance between Clydach and Hay‐on‐Wye, South Wales

AbstractThe Swansea Valley Disturbance is one of four NE‐SW belts of faulting and folding which cross the northern limb of the South Wales Coalfield syncline at variance with the normal E‐W Variscan structures. The Disturbance extends from Hay‐on‐Wye (Herefordshire) southwestwards to Clydach (near Swansea) and may extend northeastwards to Titterstone Clee Hill (near Ludlow) and southwestwards along the Tircanol Fault to Swansea Bay.The main structural elements of the Disturbance are: impersistent NE‐SW folds; NE‐SW normal faults; and NE‐SW and NNW‐SSE wrench faults. The NE‐SW structures are confined to a narrow zone which seldom exceeds two kilometres in width.It is suggested that this narrow belt of faulting and folding has been controlled mainly by sub‐Devonian basement structures, which involve faulting and/or folding. The effect of the Variscan compression was to reactivate the basement structure, which had the effect of resolving this compression along the disturbed zone to produce sinistral wrench movements. The structure of the Disturbance has been complicated by folding, produced by the Variscan force driving the Upper Palaeozoic rocks against the Lower Palaeozoic block.It is concluded that the main movements are of Variscan age and that vertical movements may have taken place in post‐Carboniferous and post‐Neogene times.

Letter to the Editor

Sir, Regardless of the eventual resting place of the Silurian-Devonian junction in South Wales and the Welsh Borders, whether it be accepted by everyone either at the base of the Ludlow Bone Bed or at the Downtonian-Dittonian junction, the recent contributions on the subject by Westoll et al. 1971 and Turner (1971) raise important questions regarding the positioning of the upper of the two possible system boundaries. Currently, the most favoured position for the Downtonian-Dittonian boundary is at the somewhat imprecise base of the 'Psammosteus' Limestone Group in the Brown Glee Hill area of Shropshire, which is marked by a fairly abrupt change from estuarine to fluviatile conditions, and is coincident with the present known incoming of the Traquairaspis fauna in that area. Westoll et al. (1971, p. 286), aware of the doubtful value offish faunas in determining this junction, comment that it would not be unreasonable to suppose that Traquairaspis might be found below this position in the Welsh Borders, and indeed this is already the case, for, in Alteryn Quarry near Newport (Mon.), Traquairaspis pococki has been found (Squirrell & Downing 1969, pp. 38 and 45) in 2½ ft (0.8 m) of micaceous greyish green sandstone at 520 ft (I58 m) below the 'Psammosteus' Limestone. This is about 420 ft (128 m) below the base of the 'Psammosteus' Limestone Beds of Newport, which approximately equate with the 'Psammosteus' Limestone Group of the Brown Clee Hill area. This occurrence of Traquairaspis, much lower than the previously known first appearance

The Old Red Sandstone of Brown Clee Hill and the Adjacent Area. I. Stratigraphy.H. W. Ball , D. L. DineleyThe Old Red Sandstone of Brown Clee Hill and the Adjacent Area. II. Palaeontology.E. I. White

Previous articleNext article No AccessNew Biological Books H. W. Ball , D. L. Dineley The Old Red Sandstone of Brown Clee Hill and the Adjacent Area. I. Stratigraphy. H. W. Ball , D. L. Dineley The Old Red Sandstone of Brown Clee Hill and the Adjacent Area. II. Palaeontology. E. I. White Alfred S. RomerAlfred S. Romer Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Quarterly Review of Biology Volume 39, Number 1Mar., 1964 Published in association with Stony Brook University Article DOIhttps://doi.org/10.1086/404102 PDF download Crossref reports no articles citing this article.

Geology of Brown Clee Hill and the Adjacent Area

Geology of Brown Clee Hill and the Adjacent Area

The old red sandstone of Brown Clee Hill and the adjacent area I. Stratigraphy

The old red sandstone of Brown Clee Hill and the adjacent area I. Stratigraphy

The Age and Relationships of the Cornbrook Sandstone

AbstractThe Cornbrook Sandstone of Titterstone Clee Hill has plants of Westphalian (Middle Coal Measures) age. It is thus probably a correlative of the lower Kinlet Group of the Forest of Wyre. The base is unconformable to the Old Red Sandstone and Carboniferous Limestone while the top is apparently conformable with Productive Coal Measures of the Sweet Coal Group, also of Middle Coal Measures age.

The highest lower old red sandstone of Brown Clee Hill, Shropshire

The unfossiliferous Lower Old Red Sandstone beds above the Ditton Series at Brown Clee Hill, Shropshire, are chiefly sandstones with subordinate silt-stones, conglomerates, limestones and dolomitic rocks. They are divided into the Abdon Series (Hillside Dolomitic Formation, 12 feet; Nordybank Sandstone Formation, 200 feet; Abdon Limestone Formation, 17 feet) overlain by the Woodbank Series (Clee Sandstone Formation, 550 feet; Monkeys Fold Sandstone Formation, 220 feet). The beds are folded into a shallow asymmetrical syncline of caledonoid trend and are overlain unconformably by eastward-dipping Coal Measures. The Abdon Series is here correlated with the upper part (Upper Dittonian) of the Red Marls of South Wales and the Woodbank Series with the Senni Beds (Breconian). The Abdon Series and Woodbank Series were formerly known as the Clee Series (here discontinued), which was correlated with the Senni Beds alone.

The Namurian Usk anticline

The Armorican Usk anticline displays evidence of ‘Sudetic’ and possibly ‘Malvernian’ antecedents, details of which may be elucidated by the use of interpolated and deduced isopachytes. A reconstructed map of the sub-Namurian floor indicates that the present form of the fold was closely delineated during mid-Carboniferous times in the ground between South Wales and the Forest of Dean. On Titterstone Clee Hill the Cornbrook Sandstone belongs to the Millstone Grit, and oversteps Avonian rocks on to Old Red Sandstone. The general relations of the strata suggest that the outlier once occupied part of the eastern flank of a northern extension, or northern homologue, of the Namurian Usk fold.

Excavations at Titterstone Clee Hill Camp, Shropshire, 1932

Titterstone Clee Hill lies some five miles due east of Ludlow. It is crowned by a camp which comprises the whole of the comparatively flat top, measuring about ½ mile from east to west and ⅓ mile from north to south. In area (71 acres) and in elevation (1,749 ft. at its summit) it is abnormal amongst hill-forts in Great Britain; both these facts have important bearings on the excavation of 1932, particularly on the lack of finds (see p. 30).A full discussion of its topographical features and environs will be published shortly in Archaeologia Cambrensis. It will be sufficient here to call attention to the camps on Brown Clee Hill and the connexion between them and Titterstone; and to the main East–West trackway, which passes close under the rampart of the latter. The two main branches of this track to the west are well attested for the prehistoric period, and there can be little doubt that the camp on Titterstone was placed to command their point of junction.

XXVII.—The Forest of Wyre and the Titterstone Clee Hill Coal Fields.

The investigations recorded in this communication were begun some years ago, and arose chiefly as the result of two papers published on the Geology of the Forest of Wyre by Mr T. C. Cantrill, B.Sc.In the latter paper Mr Cantrill, after carefully summarising all the available data respecting the age of the so-called “Permian” of the Forest of Wyre (= Enville), arrives at the following conclusions:—I. That these “Permian” rocks are of the same age as those at Hamstead in South Staffordshire.II. That the Hamstead red rocks were shown by their flora to be Upper Coal Measures.