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Durham E-Theses Mineralization of the stainmore depression and northern part of the askrigg block Small, Andrew Terry How to cite: Small, Andrew Terry (1977) Mineralization of the stainmore depression and northern part of the askrigg block, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/8341/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk 2 MINERALIZATIOM OF THE STAIMORE DEPRESSION AND NORTHER!" PART OF THE ASKRIGG BLOCK ANDREW TERRY Si'IALL, B.Sc., (Dunelm), of GREY COLLEGE Abstract; Pb - Zn - Cu - F - Ba mineralization occurs in Carboniferous Strata in veins and associated replacement flats. Veins are most productive when of small.displacement, and in thick limestones and cherts. Mineralization is especially rich near to the horizon of the Main Limestone. Faulting and therefore vein formation is controlled by basement structure especially the Stockdale Hinge Line. Bedded cherts around the eastern part of the Stockdale Line have increased competant-reactive strata thicknesses and therefore the number of productive veins. Spatial variations of mineral occurrence have been elucidated and four zones set up to describe themJ- Q Zone, quartz + chalcopyritej F Zone, fluorite ± barite + galena ± chalcopyrite + sphalerite 1 witherite; P Zone, galena i sphalerite + barite ± calcite; C Zone, copper minerals ± galena ± barite ± calcite. Parageneses etc. suggest that the Q Zone is proximal and the C Zone distal to the source. This is supported by the spatial variations of yttrium in fluorite and antimony and silver in galena. Fluid inclusion homogenization temper• atures are close to 100° C in the F Zone. Leachates of quartz, fluorite, sphalerite and barite show a systematic increase of Na/K ratio towards the north and east. Very low ratios are found suggesting an evaporitic source of solutions. Primary zonations are thought to be due to a proximity mechanism, although a small contribution is possible from mixing and heterogeneous source mechanisms. Recent oxidation has affected many deposits on the watersheds producing baritic gossans with lead ore, and secondary enrichment of copper mineralization in the C Zone is thought to be Permian. The zonal pattern, trace element studies etc, may prove useful in exploration and development when conditions are suitable for reopening the orefield. 4.' O So I^OM PLATE 1 • • ' MINERAUZATICN CP THE 3TAINM0RE DEPRESSICW AND NORTHERN PART (F THE ASKRIGG BLOCK ANDREW TERRY 31ALL, B.Sc,, (Dunelm) of CSEY COLLEGE A thesis presented for the degree of Ph.D. at the University of Durha-^, May 1977. The copyright of this thesis rests with the author. No quotation from it should be published without his prior written consent and information derived from it should be acknowledged. Frontispiece, Plate li Photomicrograph of fluorite, (pale with few inclusions) associated with barite (platen with nry s'-'all f-clu-ions). 02T', Clouds. "THE ORE IS WHERE THEY'VE LEFT ITo" -The Authoro 1l977o- iti PREFACE. This thesis has been compiled with tables, figures and plates at the end of each relevent chapter and in that order, so that the text is interupted as? little as possible. Section A is tthe main text, with Sections B,C, and D foir reference rather than fojr straight reading. CONTENTS age SECTION A A.l Introduction 1 + 2 plates (2, 3) f.p. A Structure A.2 5 Stratigraphy A.3 2A KA Mineral Occurrence AO + 7 tables + 6 plates (4 - 9) f.p.72 A. 5 Trace and Minor Element Study 73 + 6 Geochemistry Tables f.p.92 A.6 Evidence from Inclusions 93 + 2 tables + 5 plates (lO - U) f.p.110 A. 7 Conclusions 111 SECTION B B. l (a) Inner Q Zone 120 Q Zone (b) Outer Q Zone 127 (c) Stainmore 131 B.2 (a) Dent Line 132 F Zone (b) Wensleydale IA5 (c) Swaledale 164 B.3 (a) South of River Ure 195 P Zone (b) Swale - Ure Watershed 199 (c) North of River Swale 217 B. A C. Zone 248 SECTION C _ APPENDICES C.l (a) X.R.F. Analysis Conditions 258 (b) X.R.F. Standards 260 (c) Electron Probe Data 265 C.2 Computer Programs 266 C.3 Zonation of Pb - Zn - Cu - F - Ba 310 Mineralization in part of the North Yorkshire Pennines SECTION D - BIBLIOJRAPHY 335 List of Figures Following page Fig. 1.1 Production, smelt mills, and veins ^ Fig. 2.1 Structural features of northern England Fig. 2.2 Geophysical interpretation " Fig. 2.3 Stratum contours on the Main Limestone <' and major faults Fig. 2.4 Sections across the Stockdale Vein " Fig, 2.5 Formation of the Middleton-Tyas Anticline ' by salt movement Fig. 2.6 Fault refraction and vein width Fig. 2.7 Map of fault density smoothed by averaging over squares 9 x 9 km Fig. 2.8 Compound rose diagram of faults Fig. 2.9 Wrench fault details Fig. 2.10 Stockdale Line Faults Fig. 3.1 Principal rock divisions and subsurface features Fig. 3.2 Lower paleozoic outcrops and suggested " pre-Carboniferous basement Fig. 3.3 Basement "topography" Fig. 3.4 Section along grid line 37QE to illustrate <i the stratigraphy Fig. 3.5 Section along grid line 495N Fig. 3.6 Section along grid line 513N ^ Fig. 3.7 Synthetic sections of the Carboniferous • strata Fig. 3.8 Geological map of the Stainmore Trough and part of the Askrigg Block Fig. 3.9 Sections of the Upper Visean strata Vll Following page Fig. 3.10 Sections of the Namurian strata Fig. 3.11 The Permian unconformity and mineralization ^' Fig. 3.12 Productivity distribution in veins of different throw in Swaledale Fig. 3.13 Extent of cherts and isopachytes for the m Richmond Cherts Fig. 3.14. Map of the mineral veins " 72 Fig. i4.1 Paragenesis tables Fig. 4.2 Paragenesis localities Fig. 4.3 Distribution of quartz Fig. 4i.4 Distribution of fluorite Fig. 4.5 Distribution of barite >. Fig. 4.6 Strontium in barite by electron " microprobe {%) Fig. 4..7 Distribution of witherite " Fig. 4.8 Distribution of calcite and aragonite -i Fig. 4.9 X-Ray diffraction card for pyromorphite Fig. 4.9 Continued Fig. 4.10 Histograms of number of areas with specified mineral occuring in each assemblage Fig. 4.11 Histograms of proportion of areas of each assemblage with a specified mineral Fig. 4.12 Simplified paragenesis Fig. 4.13 Mineral zones of the North Yorkshire ^, Orefield Fig. 4.1i^ Relationships between minerals vi Fig. 5.1 Graphs of concentration in solid versus '^2. concentration in solution VIII Following page Fig. 5.2 Diagram of a depletion trend Fig. 5.3 Yttrium content of fluorite (ppm) it Fig. 5.4 Strontium content versus sodium/ >, potassium ratio Fig. 5.4(a) Strontium content of barite K Fig. 5.5 Silver - antimony for all galenas » (in range) Fig. 5.6 Silver - antimony for western localities 'i Fig. 5.7 Silver - antimony for Pry Hill and Keld Fig. 5.8 Silver - antimony, Staggs Fell to " Satronside Fig. 5.9 Silver - antimony, Harkerside to Cobscar Fig. 5.10 Silver - antimony, Arngill to Cleaburn M Pasture Fig. 5.11 Silver - antimony for Wensleydale Fig. 5.12 Silver - antimony, Gunnerside to Arkendale Fig. 5.13 Silver - antimony. Hurst to Feldom Fig. 5.14 Silver - smtimony for the north side of " Arkendale Fig. 5.15 Silver - antimony for the north west " Fig. 5.16 Distribution of antimony in galena " Fig. 5.17 Distribution of silver in galena (ppm) M Fig. 5.18 Silver (ppm) and Cadmium {%) content of u sphalerite Fig. 5.19 Silver and cadmium in sphalerite Fig. 6.1 Sodium/potassium ratios of fluorite and HO quart z Fig. 6.2 Sodium/potassium ratios of barite Following page Fig. 6.3 Sodium/potassium ratios of calcite and Ho sphalerite Fig. 6.4 Sodium/potassium ratios of galena and witherite Fig. 7.1 Pseudo-paragenesis diagram Fig. 7.2 Potential mineralizing solutions Fig. 7.3 Mineralization of the C Zone ACKNCWLEDGEMENTS I would like to thank Dr. G. A. L. Johnson who suggested and supervised this Ph.D. project. I am indebted to his interest, enthusiasm and also his critical reading of the manuscript. The project was sponsored by N.E.R.C. who provided the research student• ship. I would also like to thank various members of the Departm.ent of Geological Sciences:- Professor G. M. Brown, Dr. J. G. Holland, Mr. R. Phillips, Dr. A. Peckett, and Dr. D. Hurst for access to equipment and facilities etc.} Dr. F. W. Smith for advice and help with fluid inclusion workj Mr. R. G. Hardy for advice and help with X-Ray problems; Mr. G. Randall and others for technical back up; and Mr. A. Cobb, and other contemporaries for their companionship during the project. I am grateful to Professor W. S. Pitcher at Liverpool University who allowed me to continue writing up, whilst employed as demonstrator in his department. The typing was expertly carried out by Mrs.