This work is protected by copyright and other intellectual property rights and duplication or sale of all or part is not permitted, except that material may be duplicated by you for research, private study, criticism/review or educational purposes. Electronic or print copies are for your own personal, non- commercial use and shall not be passed to any other individual. No quotation may be published without proper acknowledgement. For any other use, or to quote extensively from the work, permission must be obtained from the copyright holder/s. THE SEDIMENTOLOGY AND STRATIGRAPHY OF RED BEDS IN THE WESTPHALIAN A TO C OF CENTRAL ENGLAND Thesis submitted to the University of Keele for the degree of Ph.D. by Bernard Maurice Besly B.A. 1983 M7S308 Abstract Red beds in the Westphalian A to C of Central England belong to the Etruria Formation. Examination of exposures and cores has allowed subdivision of this Formation into three Facies Associations. Facies Association I forms the gradational base of the red bed sequence. The sediments resemble the underlying Productive Coal Measures, consisting dominantly of grey organic-rich mudstones. Much of this Association is formed by seat-earth palaeosols, which occasionally contain red pigment. Facies Association II forms most of the Etruria Formation, and consists largely of dark red mudstone. Throughout there are mottled horizons which are interpreted as lateritic palaeosols. Occasional upward-fining sand bodies containing lateral accretion surfaces are present. Facies Associations I and II are interpreted as fluvial deposits. The rivers were dominated by suspended load and deposited thick overbank sequences. In Association I the overbank areas were swampy, while in Association II good drainage prevailed. Facies Association III comprises red mudstones and palaeosols, and a range of conglomerate and sandstone sheets and channel fills. This Association occurs near inferred fault bounded margins of the depositional basin. It is interpreted as the deposits of muddy alluvial fans deposited in a humid tropical climate. The petrography of the Etruria Formation is described. Derivation was from an area of mixed composition which was undergoing tropical weathering. The diagenetic alteration of the sandy sediment occurred soon after deposition in fresh water conditions. Red pigment in the mudstones was mainly inherited from a lateritic mantle in the source area, but was also partly generated by oxidation during water table fluctuation soon after deposition. Compilation of stratigraphic data shows a complex pattern of diachronism between the Etruria Formation and the Productive Coal Measures. Red bed deposition began during Westphalian A in the slowly subsiding southern margins of the depositional basin, and spread progressively northwards from Westphalian B to late Westphalian C in response to uplift of the Wales-Brabant ridge. He had been eight years upon a project for extracting sunbeams out of cucumbers, which were to be put into vials hermetically sealed, and let out to warm the air in raw inclement summers. Swift. Le supreme charme qu' on trouve a lire une page de de Selby est qu' elle vous conduit inexorablement al'heureuse certitude que des sots vous n' etes pas Ie plus grand. du Garbandier Preface This study of the Etruria Formation was started in 1976 at a time when economic pressures were causing the closure of many brick- and tileworks in the Central England coalfields. The consequent loss of clay pit exposures to the pressure of waste disposal was threatening to leave large areas without representative exposures of the Formation. The scale of this decline can be seen from the following figures. In 1900 there were 90 brickworks listed in Kelly's Directory for Staffordshire which were probably working the Etruria Formation (39 in North Staffordshire; 8 in the Cannock areaj 7 in the Aldridge areaj 36 in the Black Country). In 1976 there were only 16 brickworks working Etruria Formation clays in Staffordshire (8 in North Staffordshirej 2 in the Cannock area; 2 in the Aldridge area; 4 in the Black Country). Of 40 exposures examined in the present study, 19 have since been partially or completely infilled, are threatened with infilling, or have become degraded. It was felt that, as a matter of urgency, a record should be made of the geology of this Formation. To this end this thesis includes considerably more illustrative material than would otherwise have been necessary. It is hoped that the available exposures provided a representative sample of the Formation. At the same time large amounts of new data were becoming available as a result of the National Coal Board's 'Plan for Coal' and 'Plan 2000' exploration programmes. The National Coal Board has very kindly allowed access to these data, subject to the following minimal conditions: i) that, to protect the confidentiality of some data, no depths from surface are given, and in most cases the thicknesses of coal seams not specifiedj ii) that the mentioning of individual coal seams relates only to their stratigraphic significance, and has no implication as to any present or future economic potential. In some of the area under consideration, the re-arrangement of local authority boundaries has resulted in changes in county names. As all literature pertaining to the Westphalian employs the county names used prior to 1971, this practice has been continued in this thesis. Acknowledgements This project was initiated and supervised by Dr. John Collinson. During its final stages supervision was taken over by Professor Gilbert Kelling. I would like to thank both for their continuing interest and help. Finance for the research was provided by an NERC Research Grant. Data has been obtained from a large number of industrial undertakings. Without the help and advice of staff in these enterprises the project could not have been completed. Access to borehole cores and records has been allowed by the Western and South Midland Areas of the National Coal Board (Deep Mines), and by the Opencast Executive of the National Coal Board. Special thanks are due to Bob Hoare (Western area) and Alan Jones (South Midland Area) for granting this permission. My task has been made easier by the assistance of Lloyd Boardman, Dave Mellor, Paul Norman, Keith Whitworth, Phil Richardson and Ian Fulton, who have guided me through the NCB filing system and made arrangements to view cores of the Allotment, Playground and Kibblestone boreholes. Ros Todhunter of the Opencast Executive made arrangements for me to examine the Street's Lane borehole cores. Permission to visit exposures has been granted by all companies approached. Mr. S. Davenport and Mr. K. Pate of G.H. Downing Ltd. (now Steetly Brick Ltd.) allowed unlimited access to their quarries, and enabled me to examine the Rosemary Hill borehole cores. Thanks are also due to: D. Platt & Sons Ltd.; J. Caddick & Son Ltd.; Mr. P.R. Powell; Haunchwood Lewis Ltd.; Hawkins Tiles Ltd.; Hinton, Perry & Davenhill Ltd.; Ibstock Brick (Aldridge) Ltd.; Ibstock Brick (Himley) Ltd.; Stourbridge Brick Co. Ltd.; Baggeridge Brick Co. Ltd.; Barnett & Beddows Ltd.; Wilnecote Brick Co. Ltd.; Butterley Building Materials Ltd.; Stoneware Ltd.; Blockleys Ltd.; Stanley Bros. Ltd.; A. Adams & Sons Ltd.; The Lilleshall Co. Ltd.; Michelin Tyre Co. Ltd.; London Brick Buildings (Garden Division); Land Reclamation Co. Ltd.; and Polymeric Treatments Ltd. Advice as to the ownership and location of exposures was given by the minerals officers of the following County Councils: Staffordshire (Mrs. L. Donovan); West Midlands (Mr. J. Boldon); Shropshire (Mr. T. Butler); and Warwickshire (Mr. T. Long). The study has benefited from discussion with members of the Institute of Geological Sciences who have worked on the Westphalian. I would particularly like to thank Richard Hamblin, Michael Calver, Wyndham Evans and Albert Wilson. Information from the Sidway Mill borehole is reproduced by kind permission of the IGS. I would like to thank the technical staff in the Geology Department at Keele for their ready and cheerful assistance: in particular David Kelsall (photography); David Emley (geochemistry); and Peter Greatbach (thin section preparation). The thesis has been efficiently typed by Jackie Dray and Julie Robinson (both of Shell UK) and Joan Cliff. Vic Haddon (Shell UK) helped with the reproduction of some of the line diagrams, and with the printing. Throughout the study I have been greatly helped by the accumulated experience of Bob Hoare, Lloyd Boardman, David Thompson and Peter Turner, who have spent many hours discussing coal measures and red beds. Mavis Butterworth, Stephen Daly, Nick Kusznir, Graham Lees, Peter McCabe, Nico Rossel and Dave Stewart have all helped by providing advice, criticism and various forms of practical assistance. I would like to thank all of these for having shown an interest in Carboniferous red beds at a time when it was neither popular nor profitable to do so. Finally, I would like to express my deepest gratitude to my future wife, Jane Whieldon, without whose encouragement this thesis would not have been written. CONTENTS Preface Chapter 1. General introduction; historical and regional review 1.1 Extent and aim of study 1 1.2 Geographical occurrence; nature of exposure 2 1.3 History of previous research 1.3.1 Stratigraphy 2 1.3.2 Other previous research 6 1.4 Palaeogeographic setting 1.4.1 Setting within the context of northern Europe 9 1.4.2 Global setting 11 1.5 Notes on sedimentary facies descriptions and interpretations 13 1.6 Organization of text 15 Chapter 2. Palaeo sol description, nomenclature, and classification 2.1 Prefatory remarks 17 2.2 Definition of the term palaeosol 17 2.3 The soil profile: processes, horizon nomenclature, and profile development 18 2.4 Preservation potential of pedogenic features and soil horizons 20 2.5 Effects of intermittent deposition on horizon and profile development 22 2.6 Palaeosol features other than horizon and profile development 24 36S307 2.7 Nomenclature and classification of palaeosols 2.7.1 Approach adopted by other workers 29 2.7.2 Approach adopted in this thesis 33 Chapter 3.