Continental Rifted Margins 2

Rifted margins mark the transition between continents and oceans, which are the two first-order types of land masses on Earth. Rifted margins contribute to our understanding of lithospheric extensional processes and are studied by various disciplines of Earth Science (geology, geophysics, geochemistry). Thanks to better and wider public access to high-quality data, our understanding in these areas has improved significantly over these last two decades. This book summarizes this knowledge evolution and details where we stand today, with a series of case examples included. It is structured in a practical way, with concise text descriptions and comprehensive diagrams. Continental Rifted Margins 2 is a useful resource for students and newcomers to the rifted margin community – a "cookbook” of sorts to facilitate the reading of scientific publications and provide basic definitions and explanations.

Rifted margins mark the transition between continents and oceans, which are the two first-order types of land masses on Earth. Rifted margins contribute to our understanding of lithospheric extensional processes and are studied by various disciplines of Earth Science (geology, geophysics, geochemistry). Thanks to better and wider public access to high-quality data, our understanding in these areas has improved significantly over these last two decades. This book summarizes this knowledge evolution and details where we stand today, with a series of case examples included. It is structured in a practical way, with concise text descriptions and comprehensive diagrams. Continental Rifted Margins 2 is a useful resource for students and newcomers to the rifted margin community – a "cookbook” of sorts to facilitate the reading of scientific publications and provide basic definitions and explanations.

Non-continental margins lack thick lavas that are generated as continental crust thins immediately prior to the onset of seafloor spreading. They may form up to 30 per cent of passive margins around the world. This volume contains papers examining an active margin, fossil margins that border present day oceans, and remnants of margins exposed today in the Alps. The papers present evidence across a range of scales, from individual mineral grains, through borelide cores and outcrop, to whole margins at the crustal scale.

The continental margin of eastern Canada extends from Georges Bank at 41 degrees North to Nares Strait at 80 degrees North, almost half the distance from the Pole the equator. It is a classical example of a passive or 'Atlantic" type of continental margin with a geological history reflecting at least two 'Wilson Cycles". The first gave birth to the Iapetus Ocean, and the second to the modern Atlantic and its neighbors. The margin ties the glacial history of the Canadian landmass to the adjacent ocean basins, and so to the world's oceans. Two of the basins offshore eastern Canada, the Jeanne d'Arc Basin off Newfoundland and the Scotian Basin off Nova Scotia, contain substantial resources of oil and gas. An understanding of the geology of the margin bears directly on the evolution of the whole of the North Atlantic and the Arctic, and on the generation of hydrocarbons.

Extensive field studies on the African and North American plates during this past decade have yielded a wealth of new data and ideas about rift basins and the origin of passive margins. New surface and subsurface basins have been identified; fossils abound in strata that only recently were considered barren; oil exploration is being actively pursued in continental strata of the Richmond-Taylorsville, Sanford and Newark basins, Late Triassic marine strata have been identified in Georges Bank off the coast of Massachusetts, and the roles of wrench tectonics, successor basins and listric normal faults have challenged the classical view that these are simple extensional basins. This two part work brings together representative examples of these studies. It is not intended as an exhaustive synthesis of the subject, but rather a vehicle to present new data, new ideas and alternative views. Some of the papers present regional summaries, others attempt to relate local features to regional questions, while others describe modern rift basins as possible analogs of early Mesozoic basins. Geologic data from the Atlantic passive margins record that continental rifting of central Pangaea occurred during the latest Triassic-earliest Jurassic (Liassic), and that sea-floor spreading probably began no later than the Middle Jurassic. The primary subject of this book focuses on the Triassic-Jurassic rifting events that led to the breakup of Pangaea and the opening of the central Atlantic Ocean. Whereas other treatises have focused on the origin of the passive margins, inferred primarily from geophysical data of the offshore basins, this volume primarily and uniquely focuses on land-based field studies of the onshore synrift basins. Offshore studies of synrift basins are also included and add substantially to our understanding of the breakup. However, the onshore data base, while complementary, is different, thus providing researchers with a different insight to the questions at hand. The book is organized into four sections. Section I, Pangaean Plate in Time and Space, first locates Pangaea in space and then places the Triassic basins within an historical context on the Alleghanian-Variscan Orogens. Section 2, the offshore and onshore basins of the North American and African Plates, comprises about 70% of all papers in this book, and includes papers on structural geology, petrology, paleontology, sedimentation, organic geochemistry, vulcanism and mineral resources. Section 3, Related Mesozoic Atlantic Rift Basins, includes papers on Iberia, Western Europe, the Benue Trough and Brazil. The final section of the book, Analogs, includes the rift basins of East Africa, the Red Sea, the Gulf of Elat (Aqaba), the Dead Sea and the Rio Grande. The book is richly illustrated throughout with figures, photographs, tables and fold-out maps, including nine in full colour.