Continental Rifted Margins 1. Gwenn Peron-Pinvidic

are provided. If interested, readers are referred to books and contributions specifically dedicated to these topics. Here, the focus is directed towards the rifted margin itself by providing fundamental definitions and explaining how we study these features, how the current theories were developed, where our understanding of rifted margins currently stands and where we are headed as a research community.

       Overview

      The book comprises two volumes and is structured into three main parts:

      Volume 1 includes Parts 1 and 2. Part 1 summarizes all definitions and descriptions necessary for understanding rifted margins. Chapter 1 introduces the basic definitions of the different rift types, followed by a list of the main fault and basin types encountered in rift settings. This list is non-exhaustive but provides basic definitions. The aim is to summarize fundamental terminology so as to avoid any misunderstanding on the use of some terms in the rest of the book, not to propose full definitions. Chapter 2 describes in further detail how rifted margins are classified – spanning the different categories usually found in the literature (e.g. divergent vs. oblique, volcanic vs. non-volcanic, sediment rich vs. sediment starved). The chapter summarizes the evolution of knowledge and understanding achieved by the scientific community over the last few decades, from the initial models proposed in the 1980s to the modern views discussed today. The final part of the chapter then lists and discusses a series of scientific questions selected to illustrate the future scientific challenges our community is facing.

Part 2 explains how we study rifted margins concretely, presenting the four main methods of investigation commonly used to study rifted margins: onshore (Chapter 3), offshore (Chapter 4), numerical modeling (Chapter 5) and analogue modeling (Chapter 6). Chapter 3 explains how rifted margin settings can be studied onshore based on remnants outcropping in orogenic structural contexts. Chapter 4 lists and defines, with illustrative data examples, the main geophysical methods used on a regular basis to image and study modern offshore margins. Chapters 5 and 6 focus on the modeling strategy, including both analogue and numerical approaches.

      Volume 2 includes Part 3, which is made up of nine chapters. These chapters illustrate the topics by reviewing a series of case examples considered to be representative of the most discussed study sites at present. The aim of this part of the book is to cover a wide range of rifted margin categories, with both onshore archives and modern offshore cases.

       Color code and geological timescale

The following figures provide details of the color code used in most figures in Chapters 1 and 2, if not specified otherwise (Figure P.2), and the geological timescale used throughout this book (Figure P.3).

Figure P.2. Color code used in most figures of this book if not specified otherwise

Figure P.3. Geological timescale

       (source: International Commission on Stratigraphy)

Acknowledgments

      This book would never have been possible without the valuable help and support of many colleagues and friends.

      I would first like to thank the 25 authors who contributed to the various chapters, for their enthusiasm, confidence, professionalism and patience (in alphabetical order): T. Andersen, D. Aslanian, J. Autin, S.P. Chang, P. Chenin, M. Dlescluse, C. Gaina, J. Jakob, H.J. Kjøll, Y. Lagabrielle, S. Leroy, G. Lymer, A. McCarthy, G. Mohn, M. Moulin, C. Nonn, P.T. Osmundsen, M. Perez-Gussinye, B. Petri, M. Pubellier, T. Reston, G. Schreurs, J. Tugend, L. Watremez and F. Zwaan.

      Various colleagues also significantly contributed to the finalization of the chapters: reading, reviewing, commenting and correcting our texts and descriptions. Reviewers are rarely mentioned in scientific contributions, yet their role is key to shaping the content. I would like to warmly thank all of them for their significant help (alphabetical order): M. Bonini, D. Franke, M. Gouiza, J. Jakob, A. McCarthy, M. Nirrengarten, A. Rotevatn, K. Senger and Z. Sun.

      A special thank you to Joya Tetreault, Per Terje Osmundsen and a dear friend for their corrections, comments and suggestions for Part 1.

      I would also like to thank Sylvie Leroy and Yves Lagabrielle for inviting me to write this book, contributing to the Geosciences Encyclopaedia they supervise. Many thanks for your support and confidence during the whole process.

      Finally, personally, I would like to thank specific colleagues who have helped me to grow as a researcher through collaborations, discussions, supervisions and debates: Per Terje Osmundsen, Gianreto Manatschal, John Naliboff, Loic Fourel, Tim Redfield, Emmanuel Masini, Espen Torgersen, Katia Svendby and Suzanne McEnroe.

      Thank you.

      December 2021

PART 1 Rifting and Rifted Margins: Definitions

      1

      What is Rifting? Introduction and Basic Definitions

       Gwenn PERON-PINVIDIC1,2

       1 Geological Survey of Norway (NGU), Trondheim, Norway

       2 Department of Geoscience and Petroleum, Norwegian University of Science and Technology, Trondheim, Norway

1.1. Introduction

The Earth’s interior is composed of multiple layers of differing composition and thickness. The exterior layers are the oceanic and continental crust, followed by the upper mantle – together constituting the lithosphere (Figure 1.1). The Earth’s lithosphere is divided into tectonic plates that are in constant motion relative to each other,