INSTITUTE OF GEOLOGICAL SCIENCES Mineral Assessment Report 26 Natural Environment Research Council The limestone and Eyarn dolomite resources SK 07 SK 17 of the country around Monyash,Derbyshire MONYASH Description of 1:25 000 resource sheet SK 16 Parwlch SK05 SK15 @ SK 25 0 Grlndon Wirksworth F. C. Cox and D. McC.Bridge With a contribution by J. I. Chisholm M and N. Aitkenhead LondonHer Majesty's Stationery Office 1977 Thefirst twelve reportson the assessmentof British sand and gravel resources appearedin the Report Seriesof the Institute of Geological Sciences as a subseries. ReportNo. 13 onwards are appearingin the Mineral Assessment Report Seriesof the Institute. Details of published reports appear at theof endthis Report. It is recommended that reference to this report be made in the following form: Cox, F. C. and BRIDGE, D. McC. 1977.The limestone and dolomite resourcesof the country around Monyash, Derbyshire: Description of 1 : 25 000 resource sheet SK 16. Miner. Assess. Rep. Inst. Geol. Sci., No. 26, 137 pp. The authors F. C. Cox, BSc, PhD Institute of Geological Sciences Ring Road Halton Leeds LS15 8TQ D. Mc C. BRIDGE,BSc Institute of Geological Sciences, 154 Clerkenwell Road, London EClR 5DU ISBN 0 11 881263 7 @ Crown copyright 1977 ii PREFACE National resources of many industrial minerals may seem so large that stocktaking appears unnecessary, but the demand for minerals and for land for all purposes is intensifying and it has become increasingly clear in recent years that regional assessments of resources of these minerals should be undertaken. The publication of information about the quantity and quality of deposits over large areas is intended to provide a comprehensive factual background against which planning. decisions can be made. The interdepartmental Mineral Resources Consultative Committee recommended that limestone should be investigated, and following a feasibility study initiated in 1970 by the Institute and funded by the Department of Education and Science, the Mineral Assessment Unit began systematic surveys in 1972. The work is now being financed by the Department of the Environment and is being undertaken with the cooperation of members of the British Quarrying and Slag Federation. This Report describes the limestone and dolomite resources of some 91 km2 of country around Monyash, Derbyshire, shown on the accompanying 1:25 000 resource map SK 16. The survey was conducted by Dr F. C. Cox and Mr D. McC. Bridge with the assistance of Mrs L. C. Jones and Messrs J. T. Dove and J. L. Grayson. The work was controlled from a sub-unit based in Leeds (officer-in-charge, J. H. Hull) and is based on a geological survey at the 1:lO 560 scale conducted in 1968-1972 by Dr N. Aitkenhead, Mr J. I. Chisholm and Mr D. Price of the Institute's North-West England Field Unit. The first two officers also contributed the section on the geology. Mr J. W. Gardner, CBE (Land Agent) was responsible for negotiating access to land for drilling. The ready cooperation of land owners and tenants in this work i-s gratefully acknowledged. A. W. Woodland Director Institute of Geological Sciences Exhibition Road South Kensington London SW7 2DE 1 May, 1976 Any enquiries concerning this report may be addressed to Head, Mineral Assessment Unit, Institute of Geological Sciences, Keyworth, Nottingham, NG12 5GQ iii CONTENTS Page INTRODUCTION 1 TOPOGRAPHY 1 GEOLOGY Limestone Succession Dolomitisation Structure Lead-zinc Mineralisation ASSESSMENT PROCEDURES Field Survey Laboratory Programme Classific.ation RESULTS 7 Stratigraphical Petrography 7 Dolomitisation 17 Non-carbonate Fraction 17 Rock Chemistry 17 Colour 21 Mechanical Properties 21 THE MAP 25 Carbonate Resource Information 26 Structural and Mineralisation Data 27 Drift Geology 27 MAU Site Data 27 HorizontalSections 27 DESCRIPTION OF RESOURCE BLOCKS 27 BLOCK A 27 BLOCK B 29 BLOCK C 29 BLOCK D 30 BLOCK E 30 SUMMARY OF ASSESSMENT 35 APPENDIX A: CLASSIFICATION, TERMINOLOGY ANDGLOSSARY 37 Classification 37 Terminology 37 Glossary 38 APPENDIX B: EXPLANATIONOF FORMAT FOR BOREHOLE LOGS 41 APPENDIXC: RECORDS OF BOREHOLES AND SECTIONS 43 Resource Block A 43 Resource Block B 77 Resource Block C 91 Resource Block D 114 Resource Block E 133 REFERENCES 137 iv Page ILLUSTRATIONS Plate 2.1. Characteristicdark grey well bedded limestones of P2 age(Eyam Lime st ones) 11 Plate 2.2. Palegrey limestones of probable D2 age(Monsal Dale Limestones) 11 Plate 3.1. Flatcomplex reef ofEyamLimestones the (P2 zone) 12 Plate 4.1. LatkillDale. Dark lithofacies of theMonsal Dale Limestones (D2 zone)13 Plate 4.2. AshfordQuarry. Thinly bedded D2 limestones and chert in the 'dark facies' the Monsal Dale Limestones 13 Limestones Dale Monsal of the Plate 5.1. HartingtonStationQuarry. Massively limestonesbedded Dl 14 Plate 5.2. LatkillDale. Base of thickshell bed thein Monsal Dale Limestones 14 Plate 6.1. Pelsparite:rounded micrite grains and shell debris micritised by encrusting algae in clear spar matrix 31 Plate 6.2. Biosparite:many euhedral quartz grains in a biosparitecontaining algae and other shell debris shell other and 31 M icrite: allochems virtually absent virtually Plate allochems7.1. Micrite: 32 Plate 7.2. mosaicDolomite:equant of crystalsdolomite 32 Plate 8.1. Algalbiosparite: chiefly Dasycladacean algae with associated brachiopod and crinoid debris in debris crinoid and matrix spar a clear 33 Plate 8.2. Bryozoabiosparite: bryozoan fragments in a cloudy sparmatrix 33 Plate 9.1. Brachiopodbiomicrite: brachiopod shell and spines in a micritematrix 34 Plate 9. 2. Foraminiferalbiosparite: foraminifera and brachiopod spines in coarse spar 34 matrix Figure location1.showing themapSketch of sheet SK 16 2 Figure 2. Topography 4 Figure 3. mapSimplifiedgeology solid of the 6 Figure 4. Distributionsecondary of anddolomite mineralveins 8 Figure 5. Structure 10 Figure 6. Generalisedvertical sections ofMonsal the DaleLimestones 16 Figure 7. Contoursshowing regional variations in the distribution of thenon- carbonate fraction 18 Figure 8. Thevariation in non-carbonate fraction (acid-insoluble residue) across the northern half of sheet SK 16 20 Figure 9. Therelationship between insoluble residue and chemistry in borehole NW 6 B 22 Figure 10. Histogram of point load strength test index values 24 Figure 11. Zones of intermixing produced at the contact of disparate qualities 26 Figure 12. Distribution of res0urc.e blocks and data points 28 Figure13. Explanation of symbols used on graphical logs 40 V Page TABLES Table 1. The geological sequence in sheet SK 16 5 Table 2. Classification of limestones by purity, with possible industrial uses 9 Table 3. Thickness variations in the Monsal Dale Limestones 15 Table 4. Summary of the mean chemistry of the main limestone divisions 19 Table 5. Correlation matrix 23 Table 6. Distribution of rock colour 25 Table 7. Summary of powder reflectance results for very high purity rocks 25 Table 8. Summary of point load strength indices 26 Table 9. Summary of carbonate resources of sheet SK 16 36 Table 10. Classification of limestone rocks (based on Folk, 1959) 37 SUMMARY The study of samples specially collected from 23 cored boreholes and 15 major exposures, together with information from the records and geological maps of the Institute of Geological Sciences, form the basis of the assessment of limestone and dolomite resources in the Monyash area, Derbyshire. Eighteen boreholes were drilled under contract for the Mineral Assessment Unit and in addition, members of the Unit drilled five shallow holes using a small portable drilling machine. The limestones have been classified on the basis of their calcium carbonate content, and the accompanying 1:25 000 resource map shows the distribution of the recognised categories of limestone in the uppermost 10 m of strata, for which most information is available. Horizontal sections constructed from the borehole data and from knowledge of the regional geology, indicate the categories likely to be encountered below this depth. Five resource blocks have been outlined and for each, the geology, categories of limestones and occurrences of other rocks are described. The results of investigations of chemical and mechanical properties are presented with outline borehole logs and the data statistically analysed for the strati- graphical units described. vi The limestone and dolomite resources of the country around Monyash, Derbyshire F. C. Cox and D. McC. BRIDGE Introduction depth of the deepest working quarry; exception- ally, one borehole was drilled down to 207 m In recent years it has become clear that more to prove the geological sequence. The petro- detailed and comprehensive information on the logical, mineralogical, chemical and certain physical and chemical constitution of limestones of the physical properties of the samples have is required to generally extend knowledge of the been determined in the laboratory. Conventional resource, to facilitate land-use and mineral geological nomenclature is used for technical planning by central and local government and descriptions, ensuring compatibility between this other interests and to assist in the formulation report and the literature; a glossary is appended. of national policies to ensure continuing supplies The rocks are classified in terms of their to all the industries for which limestone is an calcium carbonate (CaCO ) content so that the 3 essentialraw material. Ideally, the information relation between limestone category and possible should relate to all the multiple uses of this end use can be easily deduced. commodity,ranging, for example, from strength, Whilst detailed results are set out in the which relates to its use as aggregate, to trace following report and its appendices, the accom- element composition, important in more panying resource map is more generalised. It specialised uses, for example, in the glass and should be noted that the distribution of limestone steel industries. The provision of such informa- categories shown on the map was determined by tion on limestone resources is the objective of reference to th'e average calcium carbonate the survey. content over the uppermost 10 m of strata.