commission de la carte géologique du monde structural map of the

Explanatory Notes
Notes explicatives
Peter MILES & Philippe BOUYSSE
Structural Map of the Atlantic Ocean
Carte structurale de l'océan Atlantique
1:20 000 000 scale
Échelle 1/20 000 000 (2012)
COMMISSION DE LA CARTE GÉOLOGIQUE DU MONDE
COMMISSION FOR THE GEOLOGICAL MAP OF THE WORLD

COMMISSION OF THE GEOLOGICAL MAP OF THE WORLD
COMMISSION DE LA CARTE GÉOLOGIQUE DU MONDE
STRUCTURAL MAP OF THE ATLANTIC OCEAN
CARTE STRUCTURALE DE L’OCÉAN ATLANTIQUE
(1st edition / 1e édition)
Explanatory notes
Notes explicatives
By
Peter Miles & Philippe Bouysse
(CGMW)
2012

© CCGM/CGMW 2012
ISBN 978-2-917310-14-4
The reproduction of excerpts or the totality of this text is authorized provided the authors and the publisher are duly credited.
Tout ou partie de ce texte peut être reproduit sous réserve d’en mentionner les auteurs et l’organisme responsable de la publication.
CCGM-CGMW
77, rue claude-bernard
75005 Paris, France
[email protected]
www.ccgm.org

Abstract
Foreword, 4
Mapping an ocean, 5
Physiography, 5
Structural Map, 5
Introduction, 5
Onshore areas, 5
Precambrian, 5
Central Atlantic Magmatic Province (CAMP), 5
Early Cretaceous rifting, 6
Parana-Etendeka Traps, 6
Cameroon Hot-Line, 6
Paleogene volcanism, 6
Neogene volcanism, 6
Hotspots, 6
«Alpine» orogens, 6
Offshore areas, 6
Magnetic Anomalies and age of the oceanic crust, 6
Structural features, 7
Anomalous submarine plateaus, 7
Subduction zones, 7
Deep-sea drill sites, 7
Sediment thickness, 7
Zone of oceanic crust deformation, 8
Continental margins, 8
Transitional Crust, 9
The seaoor spreading ridges, 8
Overview of the opening of the Atlantic Ocean and
adjacent oceanic basins, 8
Marginal Seas, 9
Seismicity, 9
Geodynamic Sketch, 9
Documents contulted in preparation of the map, 19
Maps, 19
Data sets, 19
References (text and map), 19
Résumé
Avant propos, 12
Cartographier un océan, 13
Physiographie, 13
Carte structurale, 13
Introduction, 13
Zones émergées, 13
Précambrien, 14
Province Magmatique de l’Atlantique Central
(CAMP), 14
Rifting tu Crétacé inférieur, 14
Trapps du Parana-Etendeka, 14
Ligne chaude du Cameroun, 14
Volcanisme Paléogène, 14
Volcanisme Néogène, 14
Points-chauds, 15
Orogènes «Alpins» , 15
Zones sous-marines, 15
Anomalies magnétiques et âge de la croûte océa-
nique, 15
Éléments structuraux, 15
«Plateaux océaniques», reliefs sous-marins «anor-
maux, 15
Zones de subduction, 15
Forages océaniques profonds, 16
Épaisseur des sédiments, 16
Zone de déformation de la croûte océanique, 16
Marges continentales, 16
Croûte transitionnelle, 17
Rides d’expansion océanique, 17
Grands traits de l’ouverture de l’océan Atlantique et
des bassins océaniques adjacents, 17
Mers marginales, 18
Sismicité, 18
Esquisse géodynamique, 18
Documents consultés pour la préparation de la carte, 19
Cartes, 19
Données, 19
Références (texte et carte), 19
SUMMARY / SOMMAIRE

THE STRUCTURAL MAP OF THE ATLANTIC OCEAN
At the scale of 1:20 000 000 – First edition
2012
EXPLANATORY NOTES
FOREWORD
The Commission for the Geological Map of the World (CGMW/CCGM) is a scientic Non-Governmental Organization
(NGO) recognised as Category A by UNESCO and afliated to the International Union of Geological Sciences (IUGS).
It was initiated in an early form in 1881 during the 2nd International Geological Congress (IGC) held in Bologna. During
the 1980s the CGMW co-published with UNESCO the maps of the ve oceans of the globe for the rst time (including
the ‘Antarctic Ocean’). These were part of the ‘Geological Atlas of the World’ and printed at a relatively small scale. Two
decades later our knowledge of the deep seaoor of the world’s oceans has improved to such an extent that during the
1990s the Commission decided to initiate a new series of seaoor maps featuring whole oceans, whose rst release in
2004 was the Structural Map of the Indian Ocean. This map of the Atlantic Ocean1, issued for the 34th IGC in Brisbane in
2012, is the third one of this series, being an extension of, and replacement for, the 2008 North Atlantic map. It overlaps
the adjoining Indian Ocean map. Publication of the map received nancial support from UNESCO, the Geological
Survey of Norway (2008) and IFREMER.
1 Authors of the map: Peter Miles, Philippe Bouysse and Kaiser de Souza with the contributions of Brian Tucholke, Carmen Gaina,
LaurentGernigon, Dietmar Müller, Alexandra Robert and GEUS.
ABSTRACT
This pamphlet accompanies the Structural Map of the Atlantic Ocean which synthesizes
the interpretation of geological and geophysical data compiled from oceanographic cruises
spanning several decades and their published results.
The main structural map is presented in the framework of the continental structural features.
The oceanic areas include the following parameters:
• The age of the oceanic crust in Epochs.
• Magnetic anomaly chron picks where they have been observed or interpreted.
• Seaoorspreadingaxes,activeandfossil.
• Transform faults and fracture zones.
• Anomalous relief and subduction zones.
• Seawarddippingreector(SDR)volcanicsequence.
• Earthquake epicentres and source depths.
• Hotspots.
• Deep ocean drilling sites - DSDP( IPOD), ODP and IODP - where basaltic basement or
transitional crust was reached.
• Sediment thickness - contours over oceanic crust and thinned continental crustal areas.
• Crustal deformation zones.
Summary of continental geology related to the geodynamic evolution of the ocean.
The map is accompanied here by a corresponding Geodynamic Sketch (inset in the map)
and Physiographic Map (inset in these notes). These display the tectonic plates pattern and
illustrate the morphology and their juxtaposition. This includes associated oceanic features
included in the text.
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