Ocean Margin Systems

Ocean margins are the transitional zones between the oceans and continents. They represent dynamic systems in which numerous processes shape the environment and result in impacting the utilization and hazard potentials for humans. These processes are influenced by a variety of steering mechanisms, from mountain building and climate on the land to tectonics and sea-level fluctuations in ocean margins. This book examines various aspects of regulation for the long-term development of ocean margins, of the impact of fluids and of the dynamics of benthic life at and below the seafloor in ocean margin systems.

This book is a product of the joint JGOFS (Joint Global Ocean Flux Study)/LOICZ (Land–Ocean Interactions in the Coastal Zone) Continental Margins Task Team which was established to facilitate continental margins research in the two projects. It contains signi cant information on the physical, biogeochemical, and ecosystems of continental margins nationally and regionally and provides a very valuable synthesis of this information and the physical, biogeochemical and ecosystem processes which occur on continental margins. The publication of this book is timely as it provides a very strong foundation for the development of the joint IMBER (Integrated Marine Biogeochemistry and Ecosystems Research)/LOICZ Science Plan and Implemen- tion Strategy for biogeochemical and ecosystems research in the continental margins and the impacts of global change on these systems. This initiative will move forward integrated biogeochemical and ecosystems research in the continental margins. We thank all the contributors to this volume and especially Kon-Kee Liu who has dedicated a great deal of time to ensuring a high-quality book is published. IMBER Scienti c Steering Committee Julie Hall LOICZ Scienti c Steering Committee Jozef Pacyna v 1 Preface In general, interfaces between the Earth’s larger material reservoirs (i. e. , the land, atmosphere, ocean, and sediments) are important in the control of the biogeoche- cal dynamics and cycling of the major bio-essential elements, including carbon (C), nitrogen (N), phosphorus (P), sulfur (S), and silicon (Si), found in organic matter and the inorganic skeletons, shells, and tests of benthic and marine organisms.

The evolution of the Argentina Continental Margin during the Quaternary and the stratigraphic and morphosedimentary configuration responded to climatic variability, oceanographic changes, glacioeustatic fluctuations and tectono-isostatic processes, which began to impact on the margin during previous geological periods. The final modeling of the margin was achieved in the late Miocene, when the interaction between the Antarctic and North Atlantic water-masses favored climatic and oceanographic changes with a profound effect on morphosedimentary features. In the Quaternary, the different regions of the margin distinctly responded to such changes. Whereas in the shelf the main modeling factors were the sea-level fluctuations of glacioeustatic origin and consequent marine-continental stratigraphic records, in the slope (particularly in the sector corresponding to the passive margin) the prevailing effect was the interaction between water-masses and the sea floor, giving origin to contouritic depositional systems accompanied of gravity processes responsible of turbiditic and mass-wasting deposits. Different relationships between contouritic and turbiditic facies respond to distinct combinations of oceanic circulation variability and the indirect effect on the sea floor of sea-level fluctuations. As a result of this complexity in the regional processes in the framework of the broad hemispheric oceanographic-climatic conditioning factors, the ACM can be considered as a complete archive for the Southern Ocean.

This textbook explains how mountains are formed and why there are old and young mountains. It provides a reconstruction of the Earths paleogeography and shows why the shapes of South America and Africa fit so well together. Furthermore, it explains why the Pacific is surrounded by a ring of volcanos and earthquake-prone areas while the edges of the Atlantic are relatively peaceful. This thoroughly revised textbook edition addresses all these questions and more through the presentation and explanation of the geodynamic processes upon which the theory of continental drift is based and which have led to the concept of plate tectonics. It is a source of information for students of geology, geophysics, geography, geosciences in general, general natural sciences, as well as professionals, and interested layman.

Recycling of oceanic plate back into the Earth's interior at subduction zones is one of the key processes in Earth evolution. Volcanic arcs, which form above subduction zones, are the most visible manifestations of plate tectonics, the convection mechanism by which the Earth loses excess heat. They are probably also the main location where new continental crust is formed, the so-called 'subduction factory' About 400f modern subduction zones on Earth are intra-oceanic. These subduction systems are generally simpler than those at continental margins as they commonly have a shorter history of subduction and their magmas are not contaminated by ancient sialic crust. They are therefore the optimum locations for studies of mantle processes and magmatic addition to the crust in subduction zones.

This textbook deals with the most important items in Marine Geology, including some pioneer work. The list of topics has grown greatly in the last few decades beyond the items identified by Eugen Seibold as central and now includes prominently such things as methane and climate change; that is, the carbon cycle and the Earth system as a whole. Relevant geophysical, geochemical, sedimentological and paleontological methods are shortly described. They should allow the reader to comment on new results about plate tectonics, marine sedimentation from the coasts to the deep sea, climatological aspects, paleoceanology and the use of the sea floor. The text tries to transmit to the reader excitement of marine geological research both aboard and in modern laboratories. Basic mineralogical, geochemical, biological and other relevant data and a detailed list of books and symposia are given in an Appendix. This Introduction builds on the third edition of “The Sea Floor” by E. Seibold and W.H. Berger. While much of the original text was written by Seibold, a considerable portion of the material presented in this edition is new, taking into account the recent great shift in marine geological research, some of it with great relevance to human concerns arising in a rapidly changing world.