Palencia,Tertiaryin a partand Quaternaryof the (Spain)DuerosedimentationBasin BY J. M. Mabesoone Contents Page Preface 34 Introduction 34 35 Acknowledgements ............ 36 I. Some geographical remarks ........... 1. Duero 36 basin ............. area of 39 2. The investigated in the province Palencia ...... 42 II. Previous authors ............. to 46 Bibliography up about 1938 .......... III. Stratigraphy 50 1. Lithofacies 50 Cuevas facies 50 de Biacos facies 53 Vega ........... 54 Carrion de los Condes facies ......... Relea facies 85 ............. 56 Páramos facies ............ facies 57 Zorita ............ sediments 57 Younger ........... 2. Dating of the deposits 57 Tertiary 57 sediments 58 The Palaeogene ......... sediments 58 The Neogene .......... 60 Quaternary ............. IV. Nomenclature and classification .......... 62 facies Sediment classes in the various ........ 65 Colours of 68 the deposits ........... V. 69 Grain size distribution ............ Methods of 69 investigation .......... values 70 Graphical representation and statistical ...... of the curves . 71 Interpretation . Cuevas facies 73 ............ de Biaeos facies 74 Vega ........... los Carrion do Condes facies . 81 Osornillo complex ...........83 Relea and Zorita facies 86 .......... Páramos facies ............90 92 Evaporites ............ Páramo de la a Miranda, type locality ....... 92 94 Final remarks ............ deposits 94 Quaternary ........... 96 Pisuerga terraces ........... Boedo and Valdavia terraces 96 ......... Carrion 98 terraces ........... 32 Page VI. Composition, shape and roundness of pebbles. ....... 99 Gravel composition ...........99 Morphometncal gravel analysis ........ 99 of indices Comparison some ..........loi Roundness-indices ...........101 Flatness- and slenderness-indices ........101 Pebble analyses in the various facies ........ 103 Dissymmetry-index ...........103 Roundness- and flatness-indices 103 Cuevas facies 104 Pebble composition ....... ... 104 Morphometrical analyses ..........104 of the Origin and further history conglomerates ..... 105 de Riacos facies Vega ...........106 Pebble composition ...........106 Morphometrical analyses ..........107 Origin of the quartzitie conglomerates . .108 The raña of Guardo and other remains of pediment debris . 109 terrace River deposits . .111 Terrace sediments of the Boedo and the Valdavia . .111 Pisuerga terraces 113 Carrion terraces 116 Pinal remarks ............118 VII. and roundness of sand Shape grains .........119 Introduction ............119 Distribution of sand grain types ........ 120 Cuevas facies ............120 Vega de Riacos facies 120 Carrion de los Condes facies 120 ......... Relea and Zorita facies ..........122 Páramos facies ...........122 Raña and debris .122 pediment . and Boedo terrace Pisuerga deposits ....... 122 Carrion terrace deposits . .124 Conclusions .............124 Appendix .............124 VIII. Mineral associations ............125 1. minerals Heavy ............. 125 Preparation of samples for mineral analysis . .125 Mineral counts and of the description grain types ..... 125 Grain size variations ...........126 mineral associations in the sediments Heavy Tertiary .... 128 Heavy mineral associations in the Quaternary sediments . .133 Final remarks 133 ............ 2. Light minerals 133 Introduction, method of investigation . -133 Mineral 134 description, comparison with other studies ..... Associations in the sediments Tertiary ....... 135 in the 137 Associations Quaternary sediments ....... Conclusions .............137 3. Clay minerals . .137 of fraction 137 Preparation the clay size ........ Method of 137 investigation .......... Depositional environment . .138 Cuevas facies ............140 de Eiacos facies Vega ...........140 The other Tertiary facies 142 Terrace sediments 142 Conclusions 143 33 Page IX. Geomorphology 144 Relief 144 the of the Duero basin Views on history . .145 Pre-Rhodanian of tho Duero basin 147 history ....... 147 Late-Tertiary development .......... The rafia problem . 148 Further area 149 Quaternary history of the investigated ..... Diversion of the river pattern ........ 150 Formation of the level .153 campiña . Final remarks ............155 X. Relief in source area the and palaooclimate ........ 156 Introduction 156 and Miocene Palaeogene ..........157 Cuevas facies ............157 Vega de Eiacos facies . .158 The Vindobonian and Pontian sediments 159 ...... Pliocene and Quaternary ..........160 Pliocene and Early-Pleistocene development ...... 160 The Pleistocene river terraces ........160 Recent climate and sedimentation ........161 Summary 167 Resumo 170 (en Esperanto) ............. Resumen (en español) .............173 References 176 ............... PREFACE INTRODUCTION The Tertiary sedimentary basins of the Spanish highland plateaus are well suited for sedimentologieal work, especially for establishing the relations between the sediments and the source areas in the surrounding mountain kind work started in and hitherto has ranges. This of only recently Spain, been limited to the wertem part of the Ebro basin and to some other basins in that region. The Sedimentologieal Section of the Geological and Mineralogical Institute of the Leiden University, under direction of Prof. Dr A. J. Pannekoek, selected a part of the Duero basin for this purpose. It adjoins the Cantabrian Mountain chain, where geological work is being done by Prof. Dr L. U'. de Sitter and his collaborators of the same institute. In the area chosen we could expect to obtain from sedimentologieal work some information on evolution of the Cantabrian the depositional environment, and also on the Mountains, along the lines expressed in Cadisch' well-known paper: "Das Werden der Alpen im Spiegel der Vorlandsedimentation" (1928). During the summers 1956—1958 a region south of these mountains, between the rivers and to their confluence Venta Pisuerga Carrion, up near de Baños, was investigated. The sediments were described according to their field characteristics, and some 600 samples were collected for laboratory In field the of the sediments carried analysis. the analyses coarse were out, in particular the pebble analyses of the conglomerates and of the terrace deposits. founded The laboratory work was executed in the recently sedimentological laboratory of the Geological Institute at Leiden. It consisted mainly of grain size analyses, preparing of the heavy mineral slides, and chemical investigations. X-ray analyses of clay minerals have been done by the Mineralogical and Petrological Section of the same institute. The absence of earlier studies the and therefore the on same subject, great extent of the investigated area, required that no more than the main features could be Detailed their extension investigated. studies on separate layers, on and differentiation, could not be made. Based on the data obtained by the sedimentological work, a reconstitution of the basin sedimentation was at- and the tempted, as influenced by the environments of deposition by bordering mountain chain. The following sheets of the topographical maps on the scale 1:50 000, used: published by the "Instituto Geográfico y Catastral", have been 132, 133, and Of the 164, 165, 197, 198, 235, 236, 273, 274, 311, 312. geological maps on the scale of 1:50 000 the sheets 133, 235, and 273 are the only published to now on the The area also occurs on the up investigated area. geological the scale sheets and 12. maps on 1:400 000, 11 based For the principles on which out sedimentological work was we may refer to the standard works of Cailleux (1956), Dunbar & Iiodgers (1957), Milner (1952), Pettijohn (1957), and Preobrazensky & Sarkisjan (1954). ACKNOWLEDGEMENTS On the completion of this work, the author wishes to express his gratitude to the following persons for their assistance and help in the scientific part of this investigation : For reading one or more chapters., and for giving critical remarks: Prof. Dr A. J. Pannekoek (Leiden University), Prof. Dr J. P. Bakker (Amster- dam University), Prof. Dr I). J. Docglas (Agricultural University, Wageningen), Prof. Dr O. L. Smit Sibinga (Amsterdam University), Dr J. D. de Jong (Geo- logical Survey, Haarlem), and Dr H. J. Müller (Amsterdam University). For assitance in the interpretation of the morphometrical pebble analyses; Prof. Dr J. Tricart (Strasbourg), and for the interpretation of the clay minerals: Mr. Th. Levelt (Amsterdam University). For providing literatureand other data on various problems: Dr A. Cailleux (Paris), Prof. Dr B. Meléndez (Madrid), Dr O. Riba (Madrid), Prof. Dr S. G. Sarkisjan (Moscow), Dr J. Truyols (Sabadell), and Dr Carmen Virgili (Barcelona). For assistance in the and Prof. Dr field, for discussing many problems: A. J. Pannekoek (Leiden University), Dr J. J. Nossin (Leiden University), ' and Mr. J. R. Wolf (The Hague). For the palynologieal analysis of some samples: Mr. P. van Gijzel (Leiden University). For their help in executing the teehnieal part of this investigation I am indebted to Mrs. M. T. M. Bik-Juffermans and Miss H. B. J. Rijsbergen who did the laboratory analyses, Mr. A. Verhoorn who made the x-ray films, Mr. J. Bult and Mr. C. H. Vis who executed the drawings for the illustrations, and Mr. J. Hoogendoorn who helped with the photographs. Furthermore record thanks the received I want to my for important help in correcting the text. I have to mention Mr. & Mrs. H. Holmes (London), Mr. & Mrs. Ü. Kennedy (Bishop Auckland), and Mr. F. Murphy (Ipswich) for correcting the English text, Mrs. E.