DOCSLIB.ORG

A Multi-Technique Provenance Study of the Oligocene – Recent Nile Cone Sediments and River Nile Hinterland

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Multi-Technique Provenance Study of the Oligocene – Recent Nile Cone Sediments and River Nile Hinterland A multi-technique provenance study of the Oligocene – Recent Nile cone sediments and River Nile hinterland Thesis submitted in accordance with the requirements of Lancaster University for the degree of Doctor of Philosophy Laura Diane Fielding, MESci September 2015 Abstract This thesis presents the first detailed multiproxy provenance study of the modern Nile catchment, together with Oligocene-Recent sediments of the offshore Nile cone, and demonstrates for the first time that the palaeodrainage of the Nile has remained relatively stable over the last 30 Ma. Detrital mineral and bulk-rock analyses of modern river, wadi and bedrock samples demonstrate the role of basement lithology, sedimentary recycling, and modern geomorphological features in controlling the composition of sediment reaching the Nile cone. The bulk provenance signature of the modern Nile is dominated by the input of basic detritus from the Cenozoic Ethiopian Large Igneous Province. Detrital zircon signatures are dominated by variations in bedrock lithology, and the availability of easily-eroded Phanerozoic cover sediments. These represent an important source of detritus to the river and are characterised by the presence of strongly negative εHf populations at c. 600 and 1000 Ma, and significant populations of pre-Neoproterozoic grains. Young zircon grains derived from Ethiopian Cenozoic volcanic rocks are also recognised in samples from the Blue Nile, Atbara and Nile trunk. The Sr, Nd and Hf signature of Oligocene Nile cone sediments can only be explained if there is significant input of mafic material being received from the hinterland. The Ethiopian Large Igneous Province represents the only possible source for this detritus, indicating that the Nile has been connected to the Ethiopian Highlands since this time. Zircons with U-Pb ages and hafnium isotope signatures compatible with the Ethiopian LIP have been supplied to the Nile cone since at least the Miocene (16 Ma). Such zircons were not observed in Oligocene 2 delta sediments, but Sr, Nd and Hf isotope data for Oligocene delta muds as old as 31 Ma require significant mafic input. The combined U-Pb and Hf-isotope zircon dataset for Nile catchment and cone sediments represents a significant archive that documents the evolution of the North African crust, in particular highlighting phases in the development of the Arabian Nubian Shield and amalgamation of Gondwana in late Neoproterozoic times. 3 Acknowledgments This thesis would not have been possible without the guidance, friendship, support and enthusiasm of my supervisors Yani Najman and Ian Millar. I would like to thank them for the many adventures had whilst on fieldtrips – both good and bad, and the many hours spent reading drafts, discussions on Skype, tweaking the Nu Attom and teaching me how to cook! I would also like to thank Peter Butterworth and Ben Kneller for their help both early on in the project and their valuable contributions in the final stages of thesis and paper writing. The project would not have been possible without funding from both the Natural Environment Research Council and BP Egypt, which has allowed me to conduct an exhaustive methodology and in turn produce a dataset to be proud of. The multiple analytical techniques used in this project also mean that it is the product of a collaboration from many different individuals, laboratories, universities and companies whom I would also like to thank. Invaluable technical support from Carlyn Stewart, Vanessa Pashley and Nick Roberts (NIGL), Eduardo Garzanti, Sergio Ando, Marta Padoan and Giovanni Vessoli (University of Milano-Bicocca), Dan Barfod (SUERC), Ursula Rehfeld (Corex), Mohamed Saleh (BP Egypt) and my rock crushers Laura Hobbs and Tamsin Blayney. I would also like to thank those who helped make our sample collection trips to Ethiopia, Sudan, the Red Sea Hills and the Western Desert possible (and fun!), including: Tadesse Berhanu (Addis Ababa University); Mhadia Ibrahim and her family in Sudan for their kindness and hospitality; the Mashansharti tour company in Khartoum and of course, Mr Sunshine, Mr Frank and Ibrahim for a once (twice) in a lifetime eventful desert expedition. Last but not least, I would like to thank my friends and family, particularly my husband Sam for his support and understanding over the past 4 years, and our dog, Juno. 4 Chapter 1: Introduction ........................................................................................................................ 13 1.1 Aims & Approach ........................................................................................................................ 14 1.2 Thesis Structure .......................................................................................................................... 18 1.3 The Nile Catchment Area ............................................................................................................ 20 Chapter 2: Geology of the Nile Source Regions & Nile Delta Cone Sediments.................................... 23 2.1 Geology of the Nile Source Regions ............................................................................................ 24 2.1.1 Precambrian cratons ............................................................................................................ 24 2.1.2 Arabian Nubian Shield .......................................................................................................... 25 2.1.3 The Pan-African Orogeny ..................................................................................................... 26 2.1.4 Phanerozoic cover sequences .............................................................................................. 27 2.1.5 Cenozoic uplift and eruption of flood basalts ...................................................................... 28 2.2 The Nile Cone .............................................................................................................................. 30 2.3 Previous work on the evolution of the Nile ................................................................................ 32 2.3.1 Late Eocene Palaeodrainage ................................................... Error! Bookmark not defined. 2.3.2 Oligocene Palaeodrainage ...................................................... Error! Bookmark not defined. 2.3.3 Miocene Palaeodrainage ........................................................ Error! Bookmark not defined. 2.3.4 Pliocene Palaeodrainage ......................................................... Error! Bookmark not defined. 2.3.5 Pleistocene Palaeodrainage .................................................... Error! Bookmark not defined. 2.4 Previous work on the isotope signature of Nile sediments ........................................................ 37 Chapter 3: Analytical Methods ............................................................................................................. 40 3.1 Major and Trace Element Analysis .............................................................................................. 41 5 3.2 Heavy Mineral Analysis ............................................................................................................... 42 3.2.1 Nile Cone Sands.................................................................................................................... 42 3.2.2 Nile Cone Muds .................................................................................................................... 44 3.3 Petrography ................................................................................................................................ 46 3.4 Separation Preparation for Isotope Geochemistry ..................................................................... 47 3.4.1 Sample preparation ............................................................................................................. 47 3.4.2 Weighing and leaching ......................................................................................................... 47 3.4.3 Sample dissolution ............................................................................................................... 47 3.4.4 Primary column separation .................................................................................................. 48 3.4.5 Separation of Hf ................................................................................................................... 49 3.4.6 Separation of Rb and Sr ....................................................................................................... 49 3.4.7 Separation of Sm, Nd and Lu from the bulk REE fraction .................................................... 50 3.5 Mass Spectrometry ..................................................................................................................... 50 3.5.1 Lu and Hf Analysis ................................................................................................................ 50 3.5.3 Sm and Nd analysis .............................................................................................................. 52 3.5.5 Rb and Sr analysis ................................................................................................................. 53 3.6 U-Pb Geochronology – Zircon and Rutile .................................................................................... 54 3.6.1 Laser Ablation Plasma Ionisation Mass Spectrometry ......................................................... 54 3.6.2 Data selection
Load more

Recommended publications
  • Timeline of Natural History
    Timeline of natural history This timeline of natural history summarizes significant geological and Life timeline Ice Ages biological events from the formation of the 0 — Primates Quater nary Flowers ←Earliest apes Earth to the arrival of modern humans. P Birds h Mammals – Plants Dinosaurs Times are listed in millions of years, or Karo o a n ← Andean Tetrapoda megaanni (Ma). -50 0 — e Arthropods Molluscs r ←Cambrian explosion o ← Cryoge nian Ediacara biota – z ←Earliest animals o ←Earliest plants i Multicellular -1000 — c Contents life ←Sexual reproduction Dating of the Geologic record – P r The earliest Solar System -1500 — o t Precambrian Supereon – e r Eukaryotes Hadean Eon o -2000 — z o Archean Eon i Huron ian – c Eoarchean Era ←Oxygen crisis Paleoarchean Era -2500 — ←Atmospheric oxygen Mesoarchean Era – Photosynthesis Neoarchean Era Pong ola Proterozoic Eon -3000 — A r Paleoproterozoic Era c – h Siderian Period e a Rhyacian Period -3500 — n ←Earliest oxygen Orosirian Period Single-celled – life Statherian Period -4000 — ←Earliest life Mesoproterozoic Era H Calymmian Period a water – d e Ectasian Period a ←Earliest water Stenian Period -4500 — n ←Earth (−4540) (million years ago) Clickable Neoproterozoic Era ( Tonian Period Cryogenian Period Ediacaran Period Phanerozoic Eon Paleozoic Era Cambrian Period Ordovician Period Silurian Period Devonian Period Carboniferous Period Permian Period Mesozoic Era Triassic Period Jurassic Period Cretaceous Period Cenozoic Era Paleogene Period Neogene Period Quaternary Period Etymology of period names References See also External links Dating of the Geologic record The Geologic record is the strata (layers) of rock in the planet's crust and the science of geology is much concerned with the age and origin of all rocks to determine the history and formation of Earth and to understand the forces that have acted upon it.
    [Show full text]
  • Evidence for a Giant Flood in the Central Mediterranean Sea 22 March 2018
    Evidence for a giant flood in the central Mediterranean Sea 22 March 2018 Marine scientists have uncovered evidence of one Provided by University of Malta of the largest floods in Earth's history in the central Mediterranean seafloor. The flood, known as the Zanclean flood, is thought to have ended the Messinian Salinity Crisis (MSC), a period during which the Mediterranean Sea became partially dried up. Due to shrinkage of its connection with the Atlantic Ocean, the Mediterranean Sea was transformed into a giant saline lake that was partially evaporated by the dry climate of the region 6 million years ago. One of the theories proposed to explain the refilling of the Mediterranean Sea at the end of the MSC some 640,000 years later is a catastrophic flood through the Strait of Gibraltar. By examining the most comprehensive collection of seafloor data from offshore eastern Sicily and the Maltese Islands, an international team of geoscientists has now discovered an extensive buried mass of material that is thought to have been eroded and transported by the Zanclean flood. This mass covers an area equivalent to that of the island of Crete and is up to 900 m thick in places. The passage of the Zanclean flood across the Malta Escarpment—a long submarine limestone cliff—resulted in a 1.5 km high waterfall (equivalent to five times the height of the Eiffel Tower). This water eroded a 5 km wide and 20 km long canyon on the seafloor that is still preserved underwater offshore the city of Noto (south-east Sicily).
    [Show full text]
  • Euscorpius Sicanus (Scorpiones: Euscorpiidae) from Tunisia: DNA Barcoding Confirms Ancient Disjunctions Across the Mediterranean Sea Matthew R
    Marshall University Marshall Digital Scholar Biological Sciences Faculty Research Biological Sciences 9-2012 Euscorpius sicanus (Scorpiones: Euscorpiidae) from Tunisia: DNA Barcoding Confirms Ancient Disjunctions Across the Mediterranean Sea Matthew R. Graham Pavel Stoev Nesrine Akkari Gergin Blagoev Victor Fet Marshall University, [email protected] Follow this and additional works at: http://mds.marshall.edu/bio_sciences_faculty Part of the Biodiversity Commons, Biology Commons, Evolution Commons, and the Zoology Commons Recommended Citation Graham, M.R., P. Stoev, N. Akkari, G. Blagoev & V. Fet. 2012. Euscorpius sicanus (Scorpiones: Euscorpiidae) from Tunisia: DNA barcoding confirms ancient disjunctions across the Mediterranean Sea. Serket, 13: 16-26. This Article is brought to you for free and open access by the Biological Sciences at Marshall Digital Scholar. It has been accepted for inclusion in Biological Sciences Faculty Research by an authorized administrator of Marshall Digital Scholar. For more information, please contact [email protected], [email protected]. SERKET 25 Years The Arachnological Bulletin of the Middle East and North Africa Volume 13 Part 1-2 September, 2012 Cairo, Egypt *********** ISSN: 1110-502X Serket (2012) vol. 13(1/2): 16-26. Euscorpius sicanus (Scorpiones: Euscorpiidae) from Tunisia: DNA barcoding confirms ancient disjunctions across the Mediterranean Sea Matthew R. Graham 1, Pavel Stoev 2, Nesrine Akkari 3, Gergin Blagoev 4 & Victor Fet 5 1 School of Life Sciences, University of Nevada, Las Vegas, 4505
    [Show full text]
  • Estelle Leroux
    THESETHESE / NOM / UNIVERSITE ETABLISSEMENT DE BREST présentée par Soussous le sceau le sceau de l’Universitéde l’Université européenne européenne de Bretagnede Bretagne Estelle Leroux THESE / NOM ETABLISSEMENT pour obtenir le titre de DOCTEUR DE l’UNIVERSITEpour obtenir DE le titreBREST de Préparée à ’Unité Mixte de recherche (n°6538) DOCTEUR DE L’UNIVERSITEMention Sciences DE BRESTde la Terre Institut Universitaire Européen de la Mer Ecole DoctoraleMention des : SciencesNom de la mentionde la Mer Domaines Océaniques Ecole doctorale des SCIENCES de la MER « Quantification des flux sédimentaires et de la subsidence du bassin Provençal – Annexes : Volume II » Thèse soutenue le 14 mai 2012 devant le jury composé de : Cécile Robin Maître de conférence, Université de Rennes 1 / Rapporteur Jean-Loup Rubino Expert rang Professeur, Pau / Rapporteur Philippe Joseph Professeur ENSPM, Rueil Malmaison / Examinateur Michel Séranne Chercheur CNRS, Université de Montpellier / Examinateur Jacques Deverchère Professeur, Université de Brest / Examinateur Christian Gorini Professeur UPMC, Istep / examinateur et Co-directeur de thèse Laurence Droz Chercheur CNRS, UMR6538, Brest Co-Directrice de thèse (Invitée) Daniel Aslanian Chercheur IFREMER, Brest / Tuteur Marina Rabineau Chercheur CNRS, UMR6538, Brest / Tutrice 2 Liste des publications et communications PUBLICATIONS ACCEPTEES, SOUMISES OU EN PREPARATION ————————————————————————————————————————————————————- (I) F. Bache, S.-M. Popescu, M. Rabineau, C. Gorini, J.-P.Suc, G. Clauzon, J.-L. Olivet, J.-L. Rubino, M.-C. Melinte- Dobrinescu, F. Estradan, L. Londeix, R. Armijo, B. Meyer, L. Jolivet, G. Jouannic, E. Leroux, D. Aslanian, A.T. Dos Reis, L. Macochain, N. Dumurdzanov, I. Zagorchev, V. Lesi´c, D. Tomi´c, M. Namik, Çagatay, J.-P. Brun, D. Sokoutis, I.
    [Show full text]
  • A Two-Step Process for the Reflooding of the Mediterranean After The
    A two-step process for the reflooding of the Mediterranean after the Messinian Salinity Crisis François Bache, Speranta-Maria Popescu, Marina Rabineau, Christian Gorini, Jean-Pierre Suc, Georges Clauzon, Jean-Louis Olivet, Jean-Loup Rubino, Mihaela Carmen Melinte-Dobrinescu, Ferran Estrada, et al. To cite this version: François Bache, Speranta-Maria Popescu, Marina Rabineau, Christian Gorini, Jean-Pierre Suc, et al.. A two-step process for the reflooding of the Mediterranean after the Messinian Salinity Crisis. Basin Research, Wiley, 2012, 24, pp.125-153. 10.1111/j.1365-2117.2011.00521.x. insu-00616947 HAL Id: insu-00616947 https://hal-insu.archives-ouvertes.fr/insu-00616947 Submitted on 2 Jul 2012 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. A two-step process for the reflooding of the Mediterranean after the Messinian Salinity Crisis 1,2,3 4 5 1,2 1,2 François Bache ,*, Speranta-Maria Popescu , Marina Rabineau , Christian Gorini , Jean-Pierre Suc , Georges Clauzon6, Jean-Louis Olivet7, Jean-Loup Rubino8, Mihaela Carmen Melinte-Dobrinescu9, Ferran Estrada10, Laurent Londeix11, Rolando Armijo4, Bertrand Meyer1,2, Laurent Jolivet1,2, Gwénaël Jouannic13, Estelle Leroux5,7, Daniel Aslanian1,7, Antonio Tadeu Dos Reis14, Ludovic Mocochain15, Nikola Dumurdžanov16, Ivan Zagorchev17, Vesna Lesić18, Dragana Tomić18, M.
    [Show full text]
  • Mega-Lake Floods in the Mediterranean During the Late Miocene
    Geophysical Research Abstracts Vol. 21, EGU2019-17240-1, 2019 EGU General Assembly 2019 © Author(s) 2019. CC Attribution 4.0 license. Mega-lake floods in the Mediterranean during the late Miocene Dan Valentin Palcu (1,2), Ionut Sandric (3,4), Tanja Kouwenhoven (1), Geanina Butiseaca (5), Irina Patina (6), and Wout Krijgsman (1) (1) Utrecht University, Utrecht, Netherlands ([email protected]), (2) Instituto Oceanográfico, Universidade de São Paulo, Brazil, (3) ESRI Romania, Bucharest, Romania, (4) Faculty of Geography, University of Bucharest, România, (5) Senckenberg Biodiversity and Climate Research Centre (SBiK-F), Frankfurt, Germany, (6) Geological Institute, Russian Academy of Sciences, Moscow, Russia Many large marginal water bodies on Earth, partially disconnected from the open ocean by shallow sills, have been land-locked in ancient times (e.g., the Mediterranean Sea; the Black Sea, the modern Baltic Sea region). Disconnected from the global ocean, these “sea-lakes” would expand or contract, controlled by their hydrological budget. Spectacular marine flooding events would occur when basins with negative water budgets would reconnect with the ocean while lake burst floods would characterize the reconnection of the basins with positive water budgets. Key examples of marine floods are the Zanclean flood in the Mediterranean and the Black Sea Deluge, also known as Noah’s flood, while the archetypes lake burst floods are best exemplified by the erosional features of the English Channel, lake Bonneville and Lake Missoula floods. Here, we show that Paratethys, a Miocene mega-lake from central Eurasia has generated at least two mega-floods into the Mediterranean during Messinian times via a river system, which we call Styx.
    [Show full text]
  • The Zanclean Megaflood of the Mediterranean
    Earth-Science Reviews 201 (2020) 103061 Contents lists available at ScienceDirect Earth-Science Reviews journal homepage: www.elsevier.com/locate/earscirev The Zanclean megaflood of the Mediterranean – Searching for independent evidence T ⁎ Daniel Garcia-Castellanosa, , Aaron Micallefb,c, Ferran Estradad, Angelo Camerlenghie, Gemma Ercillad, Raúl Periáñezf, José María Abrilf a Instituto de Ciencias de la Tierra Jaume Almera, ICTJA-CSIC, Barcelona, Spain b Marine Geology and Seafloor Surveying, Department of Geosciences, University of Malta, Msida, MSD 2080, Malta c Helmholtz Centre for Ocean Research, GEOMAR, Kiel, Germany d Instituto de Ciencias del Mar, ICM-CSIC, Barcelona, Spain e Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS), Trieste, Italy f University of Sevilla, Spain ABSTRACT About six million years ago, the Mediterranean Sea underwent a period of isolation from the ocean and widespread salt deposition known as the Messinian Salinity Crisis (MSC), allegedly leading to a kilometer-scale level drawdown by evaporation. One of the competing scenarios proposed for the termination of this en- vironmental crisis 5.3 million years ago consists of a megaflooding event refilling the Mediterranean Sea through the Strait of Gibraltar: the Zanclean flood. The main evidence supporting this hypothesis is a nearly 390 km long and several hundred meters deep erosion channel extending from the Gulf of Cádiz (Atlantic Ocean) to the Algerian Basin (Western Mediterranean), implying the excavation of ca. 1000 km3 of Miocene sediment and bedrock. Based on the understanding obtained from Pleistocene onshore megaflooding events and using ad-hoc hydrodynamic modeling, here we explore two predictions of the Zanclean outburst flood hypothesis: 1) The formation of similar erosion features at sills communicating sub-basins within the Mediterranean Sea, specifically at the Sicily Sill; and 2) the accumulation of the eroded materials as megaflood deposits in areas of low flow energy.
    [Show full text]
  • Architecture and Sequence Stratigraphy of the Upper Coralline
    Received: 18 November 2020 | Revised: 3 February 2021 | Accepted: 3 February 2021 DOI: 10.1002/dep2.138 ORIGINAL RESEARCH ARTICLE Architecture and sequence stratigraphy of the Upper Coralline Limestone formation, Malta— Implications for Eastern Mediterranean restriction prior to the Messinian Salinity Crisis Or M. Bialik1 | Raymond Zammit2 | Aaron Micallef1,3 1Marine Geology & Seafloor Surveying, Department of Geosciences, University of Abstract Malta, Msida, Malta The Eastern and Western Mediterranean are separated by an elevated plateau that 2School of Earth and Environmental regulates water exchange between these two basins. The Maltese archipelago, situ- Sciences, Cardiff University, Cardiff, UK ated atop this topographic high, offers a unique window into the evolution of this pla- 3GEOMAR Helmholtz Centre for Ocean teau in the lead up to the Messinian Salinity Crisis. The Upper Coralline Limestone Research Kiel, Kiel, Germany Formation was deposited between the late Tortonian and the early Messinian and Correspondence was probably terminated by palaeoceanographic events related to the Messinian Or M. Bialik, Marine Geology & Seafloor Surveying, Department of Geosciences, Salinity Crisis. It represents the youngest Miocene sedimentary deposits outcrop- University of Malta, Msida, Malta. ping in the Maltese archipelago. This shallow-water carbonate unit can be used to Email: [email protected] trace palaeoenvironmental changes atop the sill between the Eastern and Western Funding information Mediterranean and to explain the possible
    [Show full text]
  • [Tel-00790852, V1] Quantification Des Flux Sédimentaires Et De La
    THESETHESE / NOM / UNIVERSITE ETABLISSEMENT DE BREST présentée par tel-00790852, version 1 - 21 Feb 2013 Soussous le sceau le sceau de l’Universitéde l’Université européenne européenne de Bretagnede Bretagne Estelle Leroux THESE / NOM ETABLISSEMENT pour obtenir le titre de DOCTEUR DE l’UNIVERSITEpour obtenir DE le titreBREST de Préparée à ’Unité Mixte de recherche (n°6538) DOCTEUR DE L’UNIVERSITEMention Sciences DE BRESTde la Terre Institut Universitaire Européen de la Mer Ecole DoctoraleMention des : SciencesNom de la mentionde la Mer Domaines Océaniques Ecole doctorale des SCIENCES de la MER « Quantification des flux sédimentaires et de la subsidence du bassin Provençal – Annexes : Volume II » Thèse soutenue le 14 mai 2012 devant le jury composé de : Cécile Robin Maître de conférence, Université de Rennes 1 / Rapporteur Jean-Loup Rubino Expert rang Professeur, Pau / Rapporteur Philippe Joseph Professeur ENSPM, Rueil Malmaison / Examinateur Michel Séranne Chercheur CNRS, Université de Montpellier / Examinateur Jacques Deverchère Professeur, Université de Brest / Examinateur Christian Gorini Professeur UPMC, Istep / examinateur et Co-directeur de thèse Laurence Droz Chercheur CNRS, UMR6538, Brest Co-Directrice de thèse (Invitée) Daniel Aslanian Chercheur IFREMER, Brest / Tuteur Marina Rabineau Chercheur CNRS, UMR6538, Brest / Tutrice tel-00790852, version 1 - 21 Feb 2013 2 Liste des publications et communications PUBLICATIONS ACCEPTEES, SOUMISES OU EN PREPARATION ————————————————————————————————————————————————————- (I) F. Bache, S.-M. Popescu, M. Rabineau, C. Gorini, J.-P.Suc, G. Clauzon, J.-L. Olivet, J.-L. Rubino, M.-C. Melinte- Dobrinescu, F. Estradan, L. Londeix, R. Armijo, B. Meyer, L. Jolivet, G. Jouannic, E. Leroux, D. Aslanian, A.T. Dos Reis, L. Macochain, N. Dumurdzanov, I. Zagorchev, V.
    [Show full text]
  • An Exploratory Modelling Study on Sediment Transport During The
    1 An exploratory modelling study on sediment transport 2 during the Zanclean flood of the Mediterranean ∗ † 3 R. Peri´a˜nez , J.M. Abril Dpto. F´ısica Aplicada I ETSIA, Universidad de Sevilla Ctra. Utrera km 1, 41013-Sevilla, Spain ‡ 4 D. Garcia-Castellanos Instituto de Ciencias de la Tierra Jaume Almera, CSIC Sol´e i Sabar´ıs s/n 08028-Barcelona, Spain. § ¶ 5 F. Estrada, G. Ercilla Instituto de Ciencias del Mar, CSIC Passeig Mar´ıtim de la Barceloneta 37-49 08003-Barcelona, Spain 6 April 11, 2018 7 Abstract 8 A nearly 400 km long erosion channel through the Strait of Gibraltar has been 9 interpreted as evidence for a catastrophic refill of the Mediteranean at the end of 10 the Messinian salinity crisis, 5.33 milion years ago. This channel extends from 11 the Gulf of Cadiz to the Algerian Basin and implies the excavation of ca. 1000 3 12 km of Miocene sediment from the Alboran Basin and bedrock from the Strait of 13 Gibraltar. The fate of these eroded materials remains unknown. In a first attempt 14 to predict the distribution of those flood deposits, here we develop a numerical 15 model to simulate the transport of material eroded from the Strait of Gibraltar. It 16 is a Lagrangian model based upon standard sediment transport equations able to 17 simulate suspended and bed-load sediment transport. Water circulation during the ∗[email protected] †[email protected] ‡[email protected] §[email protected][email protected] 1 18 flood has been obtained from a hydrodynamic model of the whole Mediterranean Sea 19 previously developed by the authors and applied to the Zanclean flood.
    [Show full text]
  • Decoding the Mediterranean Salinity Crisis
    Sedimentology (2009) 56, 95–136 doi: 10.1111/j.1365-3091.2008.01031.x Decoding the Mediterranean salinity crisis WILLIAM B. F. RYAN Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA (E-mail: [email protected]) ABSTRACT This historical narrative traces the steps to unravel, over a span of 40 years, an extraordinary event in which 5% of the dissolved salt of the oceans of the world was extracted in a fraction of a million years to form a deposit more than 1 million km3 in volume. A buried abyssal salt layer was identified with reflection profiling and sampled during the Deep Sea Drilling Project, Leg 13. The dolomite, gypsum, anhydrite and halite in the drill cores paint a surprising picture of a Mediterranean desert lying more than 3 km below the Atlantic Ocean with brine pools that shrank and expanded by the evaporative power of the sun. The desert drowned suddenly when the Gibraltar barrier gave way. The explanation of ‘deep-basin, shallow-water’ desiccation and the notion of a catastrophic Zanclean flood had a mixed reception. However, the hypothesis became broadly accepted following subsequent drilling expeditions. Nevertheless, as experts examined the evaporate facies and sequences of equivalent age in the terrestrial outcrops, weaknesses appeared in the concept of repeated flooding and drying to account for the magnitude of the deposits. The ‘Rosetta Stone’, used to decipher conflicting interpretations, turns out not to be the deposits but the erosion surfaces that enclose them. These surfaces and their detritus – formed in response to the drop in base level during evaporative drawdown – extend to the basin floor.
    [Show full text]
  • Noto Canyon and the Western Ionian Basin (Offshore Sicily)
    The Zanclean flood hypothesis Searching for independent evidence Daniel Garcia-Castellanos, CSIC-Barcelona Aaron Micallef, Malta U. Angelo Camerlenghi, Trieste OGS Ferran Estrada, CSIC-Barcelona Gema Ercilla, CSIC-Barcelona P. Bohorquez, Jaén Univ. J.D. del Moral-Erencia, Jaén U. R. Periáñez, Sevilla U. J.M. Abril, Sevilla U. CSIC-ICTJA, Barcelona, Spain Widespread erosion of the Mediterranean continental margins suggest the exposure of the seafloor by an evaporative drawdown of kilometric scale during the Messinian Salinity Crisis. An erosion trough across the Strait of Gibraltar is the main support for a catastrophic refill of the Mediterranean after the MSC. It runs from the Atlantic Ocean to the Mediterranean Sea and it’s visible in reflection seismic surveys, under a Plioquaternary sedimentary cover. >400km long 2-10 km wide Garcia-Castellanos et al., 2009, Nature Messinian Erosion Surface map in Alborán (W Mediterranean). Updated seismic survey + borehole data Red lines show the proposed pathway and the channel excavated by the flood. Two open questions are: 1) Where did that eroded rock (~1000 km3) go to? 2) Is there an equivalent feature at the threshold where the W Mediterranean should have overtopped into the E Mediterranean? Attempting at answering those questions, what follows is partly published in this recent article (open Access): Evidence from • the Alborán Sea seismic profiles • Ionian Sea seismic profiles • Numerical modeling Shear stress [log, Pa] Where is the erosion/deposition occurring during the flood? Hints from 2D hydrodynamic modeling: t Sand transpor Shear stress [Pa] = rho_w * fric_coeff * vel^2 Calculated from the setting by Periañez & Abril, 2015 Peak discharge of the Zanclean Flood (100 Sv) Periañez et al., 2019 Similar hydrodynamic modeling at the Noto Canyon and the western Ionian Basin (offshore Sicily) (a) Calculated water flow velocities at rising water levels of the E Med.
    [Show full text]