Evolution of the Pyrenees during the Variscan and Alpine Cycles, Volume 2

Nicolas Saspiturry is a teacher–researcher specializing in the tectonic– sedimentary and thermal evolution of sedimentary basins. He has devoted much of his work to the Pyrenees.Jessica Uzel has a doctorate in geology and a degree in life, earth and universe sciences. She specializes in the post-compressive evolution of the Pyrenean domain.Alexandre Ortiz has a doctorate in geology. He specializes in the syn- to post-compressive evolution of the North Pyrenean foreland basin.

• Preface xvNicolas SASPITURRY, Jessica UZEL and Alexandre ORTIZChapter 1 Structure of the Pyrenees at the Crustal Scale 1Antonio TEIXELL and Pierre LABAUME1.1 Introduction 11.2 Tectonic framework of the Pyrenean belt 21.3 Crustal investigations by deep seismic reflection surveys 21.3.1 Results of the ECORS profiles across the Pyrenees 31.3.2 Contributions by recent geophysical surveys 71.4 Significance of high-density bodies at crustal depths 101.5 Serial crustal sections for the Pyrenees 111.5.1 The ECORS-Pyrenees section 121.5.2 The Nestes-Cinca section 141.5.3 The Chaînons Béarnais-Jaca section 151.5.4 The Basque-Cantabrian Pyrenees section 161.5.5 The Eastern Pyrenees section 181.6 Models for the crustal structure previous to the Pyrenean orogeny 201.7 The nature of the rifted continental margins 221.8 Rift inheritance and orogeny 221.9 References 26Chapter 2 Syncompressive Alluvial Conglomerates: Markers of Exhumation in the Eastern Pyrenees 35Thierry NALPAS2.1 Introduction 352.2 Geological context 362.3 Study methodology 372.4 Conglomerates of the eastern Pyrenees 382.4.1 The North Pyrenean area of Puivert 382.4.2 The South Pyrenean sector of Sant Llorenç de Morunys 422.4.3 Interpretation 452.5 Discussion – clasts as markers of the exhumation of the Pyrenees 472.6 Conclusion 492.7 References 50Chapter 3 Tectono-Sedimentary Evolution of the Aquitaine Basin from the Priabonian to the Pliocene 53Alexandre ORTIZ, François GUILLOCHEAU, Cécile ROBIN, Éric LASSEUR, Justine BRIAIS, Jessica UZEL and Nicolas SASPITURRY3.1 Introduction 533.2 Definitions and keywords related to foreland basins 563.3 Synthesis of structural, sedimentary, paleogeographic and biostratigraphic data from the Aquitaine Basin 583.3.1 Main tectonic structures of the Aquitaine Basin 583.3.2 Deformation timelines 593.3.3 Paleogene sedimentary infill of the Aquitaine Basin 603.3.4 Biostratigraphic calibrations 623.4 Evolution of sedimentary infill from the Priabonian to the Pliocene 643.4.1 Paleogeography of the Late Priabonian (35.1–33.8 Ma) 643.4.2 The Oligocene period (33.9–23.03 Ma) 703.4.3 The period from the Aquitanian to the Burdigalian (23.03–15.97 Ma) 783.4.4 Paleogeography of the Langhian and Serravallian 913.4.5 Paleogeography of the Tortonian and Messinian 1023.4.6 Paleogeography of the Pliocene 1073.5 Summary of the post-Priabonian tectonic evolution of the Aquitaine Basin 1103.5.1 The Oligocene, final phase of syn-orogenic structuring 1113.5.2 The Aquitanian, the transition to a post-orogenic regime 1123.5.3 From the Burdigalian to the Tortonian, the final major deformation phase in the Aquitaine Basin 1143.6 Conclusion 1173.7 References 117Chapter 4 The Source-to-Sink Evolution of the Jaca Basin (Southern Pyrenees) 131Marta ROIGÉ, David GÓMEZ-GRAS, Antonio TEIXELL, Xavi COLL and Salvador BOYA4.1 Introduction and geological background 1314.2 Chronostratigraphic framework of the Jaca basin 1344.3 Source area domains during the evolution of the basin 1384.3.1 Source rock bulk petrology 1394.3.2 U-Pb zircon geochronology 1394.3.3 Heavy mineral content 1404.4 Provenance evolution of the Jaca basin 1414.4.1 The Early to Middle Eocene basin: Hecho Group turbidites 1414.4.2 The Middle Eocene to Early Miocene basin: from transitional to terrestrial environments 1444.5 References 152Chapter 5 The Western Mediterranean Extension and the Dismantling of the Eastern Pyrenees 161Antonio TEIXELL and Pierre LABAUME5.1 Introduction 1615.2 Origin and timing of extensional deformation 1625.3 The tectonic dismantling of the eastern Pyrenees mountain chain 1655.4 References 168Chapter 6 A “Late Pyrenean” Phase at the Burdigalian/ Langhian Transition (Corbières, France)? 171Oriane PARIZOT6.1 Introduction 1716.2 The eastern north Pyrenean domain: the Corbières region 1756.2.1 Geological context 1756.2.2 Geodynamic timeline 1776.3 Discovery of a new tectonic event at the Burdigalian/Langhian transition in the Corbières 1796.3.1 U-Pb data 1796.3.2 Structural data 1816.4 A “Late Pyrenean” phase at the scale of the orogen? 1836.5 Origins of the event 1866.5.1 The Kabylies? 1866.5.2 The Gulf of Lion? 1876.5.3 A tectonic event on the scale of the European platform? 1886.6 Conclusion 1886.7 References 189Chapter 7 Planation Surfaces and Post-Compressive Evolution of the Pyrenean Chain 197Jessica UZEL, Nicolas SASPITURRY and Alexandre ORTIZ7.1 Geological context 1977.1.1 Structural domains of the Pyrenees 1977.1.2 Deep structure of the Pyrenees 2017.1.3 Formation of the Pyrenean relief 2027.1.4 Cenozoic climate history of the Pyrenees 2077.2 Relict planation surfaces and weathering effects in the Pyrenees 2087.2.1 High-elevation relict planation surfaces 2087.2.2 Weathering and relict planation surfaces 2127.3 Origin of the relics of Pyrenean planation surface(s) 2157.3.1 Age of the relics of the highest planation surface 2167.3.2 Models for the formation of the Pyrenean planation surfaces 2187.4 Summary and discussion 2257.5 References 228Chapter 8 Dating and Erosion Rates of the Pyrenees: In Situ-Produced Cosmogenic Isotopes 241Vincent REGARD, Sébastien CARRETIER and Sandrine CHOY8.1 In situ-produced cosmogenic isotopes 2418.1.1 History 2418.1.2 The main in situ-produced cosmogenic isotopes used in Earth sciences 2428.1.3 Differential equation governing the concentration of a cosmogenic isotope at the surface 2438.2 Dating the exposure of a rock to cosmic rays 2508.2.1 Dating glacial polished bedrock surfaces and moraines to establish the chronology of deglaciation 2508.2.2 Dating of exposure of alluvial deposits 2548.2.3 Uncertainty in exposure dating 2578.3 Quantification of the denudation rate in the Pyrenees 2578.3.1 Calculation of denudation rates from cosmogenic isotopes 2578.3.2 Application in the Pyrenees 2588.3.3 Uncertainty in denudation rates 2608.4 Burial dating of a rock 2608.4.1 Calculation of a burial age from a pair of cosmogenic isotopes 2608.4.2 Application in the Pyrenees 2628.4.3 Uncertainty on burial datings 2628.5 Summary: cosmogenic isotopes in the Pyrenees 2638.6 References 263Chapter 9 Post-Compressive Incision of the Pyrenean Valleys: Insights from Karst Records 267Amandine SARTÉGOU and Didier L. BOURLÈS9.1 How can we trace the post-compressive evolution of the Pyrenean chain? 2679.2 Karst in the Pyrenees 2699.2.1 Pyrenean karsts, witnesses of paleoenvironments since the Paleozoic 2709.2.2 The eastern Têt valley and its relation with the Mediterranean domain 2709.2.3 The upper Aude valley and its relation with the Sault plateau 2739.2.4 The valleys of the Ariège and their large networks 2759.2.5 The karsts of the central Pyrenees and the Basque country 2769.3 How to record valley incision with karsts 2779.3.1 Epiphreatic model and chronology of valley excavation 2779.3.2 Karst: sediment trap and witness of landscape evolution 2809.4 How to date sediments trapped in karst 2829.4.1 Use of cosmogenic burial durations 26 Al/ 10 Be: a validated method for Plio-Quaternary evolution 2829.4.2 Use of the 10 Be- 21 Ne pair: a major analytical development for reconstructing the Miocene evolution of valleys 2839.4.3 Relationship between cosmogenic burial durations and the position of the base level at a given instant 2849.5 Main results from the study of karsts 2859.5.1 Incision rates of the upper Têt valley since the Burdigalian 2859.5.2 Aude valley: between tectonic influence and Mediterranean influence 2879.5.3 Ariège valley: impact of tectonics and glaciations 2889.5.4 The valleys of the central and western Pyrenees: a promising outline 2899.6 Drivers of incision of the Pyrenean valleys from the Miocene to the present 2909.6.1 The valleys of the eastern Pyrenees connected to the Mediterranean 2909.6.2 The valleys of the western Pyrenees connected to the Atlantic and subject to glaciations 2929.6.3 Lessons from the karsts 2939.7 Conclusion and prospects 2949.8 References 295Chapter 10 Evolution of the Geothermal Gradient from Cretaceous Rifting to Pyrenean Compression (Western Pyrenees) 301Nicolas SASPITURRY, Thierry BAUDIN, Abdeltif LAHFID, Laurent GUILLOU-FROTTIER, Benoit ISSAUTIER, Philippe RAZIN, Alexandre ORTIZ and Jessica UZEL10.1 Introduction 30110.2 Tectono-sedimentary evolution of the Mauléon Basin from the Mesozoic to the Cenozoic 30410.2.1 The Cretaceous rifting phase: formation of the hyper-extended Mauléon Basin 30410.2.2 The Pyrenean compression phase: inversion of the Cretaceous rift basin and building of the orogenic prism 30710.3 RSCM thermometry, an overview of the method and its use in the Pyrenees 30910.3.1 Methodology and analysis tool 31110.3.2 History of the application of the RSCM method in Pyrenees 31210.4 The geothermal gradient: definition 31410.4.1 The rifting context 31510.4.2 The orogenic context 31710.4.3 The erosional context 31810.5 Mesozoic to Cenozoic evolution of the geothermal gradient of the Mauléon Basin: application of RSCM thermometry 32010.5.1 Thermal peak age in the Mauléon Basin 32210.5.2 Cretaceous paleogeothermal gradients estimated from RSCM thermometry 32210.5.3 Distribution of the geothermal gradient from the proximal to distal domain of the Mauléon Basin during the Cretaceous 32610.5.4 Evolution of the geothermal gradient during Pyrenean compression 32810.6 Numerical thermal modeling of the Mauléon Basin 33010.6.1 Opening of the Mauléon Basin 33110.6.2 Stage of synorogenic sedimentation 33210.6.3 Stage of continental collision and erosion 33310.6.4 Postcollisional quiescence 33410.7 References 335Chapter 11 Pleistocene and Holocene Glacial Fluctuations in the Pyrenees 343Magali DELMAS11.1 Introduction 34311.2 From the first cartographies to a relative chronostratigraphy of Pyrenean glacial margin deposits 34511.2.1 A long sequence of moraine deposits into three sedimentary units 34511.2.2 Confrontation between polyglacialists and monoglacialists (1950s–1960s) 34711.2.3 Rehabilitation of polyglacialism and repositioning of the fronts contemporary with the maximum ice extent of the last glaciation 35011.3 Radiocarbon dating contribution 35311.3.1 Chronological model established on the north-facing slope 35411.3.2 A chronological model confirmed on the southern slope? 36111.4 Recent diversification of dating methods 36811.4.1 The contribution of OSL ages 36811.4.2 The contribution of in situ-produced cosmogenic isotopes 37011.5 Conclusion 39211.6 References 394Chapter 12 Digital Geological Map of the Northern Slope of the Pyrenees at 1:250,000 Scale 407Bernard MONOD12.1 Construction of the digital geological map of the northern slope of the Pyrenees 40712.1.1 Work of the RGF 40812.1.2 Map legend, structures and contour smoothing 40812.2 Presentation, organization and dissemination of the map data 40912.2.1 Presentation of the main cartographic features of the Pyrenees 40912.2.2 Organization of the data composing the digital map 41012.3 Dissemination and availability of the digital geological map data at the 1:250,000 scale 41512.4 References 415Chapter 13 The Corundums of the Albitites Related to the Urdach Lherzolites: Lapidary Enhancement 417Jean-Éric ROSE, Pierre MONCHOUX, Philippe DE PARSEVAL, Christian PIN, Thierry AIGOUY, Didier BÉZIAT and Guillaume ESTRADE13.1 The magmatic albitites related to the lherzolites 41713.1.1 Structural characteristics 41913.1.2 Mineralogical characteristics 41913.1.3 Geochemical characteristics 42213.1.4 Genetic hypothesis for the Urdach albitites 42313.1.5 Possible origin of corundum xenocrysts and polycrystalline inclusions in alkaline basaltic provinces 42413.1.6 A unique example of emplacement related to the Pyrenean orogeny 42413.2 Corundum 42513.2.1 “Primary” corundum crystals 42513.2.2 “Secondary” corundum crystals 42613.3 The value of the “amateur” perspective in science 42713.3.1 Field research and sample selection 42813.3.2 Value of lapidary work prior to scientific analysis 42813.4 References 430List of Authors 433Index 437