The NE Atlantic Region


Book Description

The NAG-TEC project was a collaborative effort by the British Geological Survey, the Geological Survey of Denmark and Greenland, the Geological Survey of Ireland, the Geological Survey of the Netherlands, the Geological Survey of Northern Ireland, the Geological Survey of Norway, Iceland GeoSurvey and the Faroese Geological Survey (Jarðfeingi), along with a number of academic partners and significant support from industry. The main focus was to investigate the tectonic evolution of the region with a particular emphasis on basin evolution along conjugate margins. A key outcome was the development of a new tectonostratigraphic atlas and database that includes comprehensive geological and geophysical information relevant for understanding the Devonian to present evolution of the NE Atlantic margins. These provide the foundation upon which ongoing research and exploration of the area can build. This Special Publication provides some of the first scientific results and analysis based on the project, including regional stratigraphic analysis and correlations, crustal structure and interpretation of geophysical data sets, plate kinematics and the evolution of igneous provinces.




The Greenland Caledonides


Book Description

Accompanying CD-ROM contains fold. col. map, entitled, in both formats, "Caledonian orogen : East Greenland 70°N-82°N : Geological map 1:1 000 000.




Sedimentation History Along the East Greenland Margin


Book Description

The change in global climate is one of the highly speculative aspects in the Northern Hemipsphere, especially the onset of glaciation. Advances and retreats of grounded ice sheets during glacial- interglacial times play an important role in terms of the deposition of large sediment deposits. Depositional patterns on the continental slope and rise reflect interactions between the effects of ice sheet fluctuations, mass transport processes and bottom currents. A for the first time applied seismostratigraphy on the Northeast Greenland margin made it possible to differentiate between glacial (younger than Middle Miocene) and pre-glacial (older than Middle Miocene) sediment units. Glacial advances and retreats appear not to have been synchronous along the continental margin. Therefore, either north of 70 N the extension of the shelf by glacial erosion seems to be more intensive like on the Southeast Greenland margin or the onset of glaciation started earlier in the north than in the south. This study demonstrates the interaction between sediment accumulation, climatic changes and changes in ocean circulation.




Regional Geology and Tectonics: Phanerozoic Passive Margins, Cratonic Basins and Global Tectonic Maps


Book Description

Expert petroleum geologists David Roberts and Albert Bally bring you Regional Geology and Tectonics: Principles of Geologic Analysis, volume one in a three-volume series covering Phanerozoic regional geology and tectonics. It has been written to provide you with a detailed overview of geologic rift systems, passive margins, and cratonic basins, it features the basic principles necessary to grasping the conceptual approaches to hydrocarbon exploration in a broad range of geological settings globally. A "how-to" regional geology primer that provides a detailed overview of tectonics, rift systems.




The Geology of Continental Margins


Book Description

The continental margins of the world constitute the most impressive and largest physiographic feature of the earth's surface, and one of fundamentally great geological significance. Continental margins have been the subject of increasing attention in recent years, an interest focused by a body of new data that has provided new insights into their character. This interest was further stimulated by the realization that, in addition to the abundant living resources, continental margins contain petroleum and mineral resources that are accessible with existing technology. This realization, along with their basic geological importance, has provoked further research into the nature of continental margins throughout the world. A summary of these findings, as related to both recent and ancient continental margins, is the subject of this book. At various times in the past we had been approached individually to prepare a basic reference to continental margins; we then proposed to do such a volume jointly. However, the stimulus for the present volume eventually arose from a Penrose Conference arranged through the Geological Society of America. This conference was attended by specialists of numerous disciplines and from throughout the world, many of whom insisted that such a volume would be both timely and useful. Consequently, we agreed to undertake the task of assembling this book, with the objectives of making it available as soon and as inexpensively as possible.




Non-volcanic Rifting of Continental Margins


Book Description

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.




World Atlas of Submarine Gas Hydrates in Continental Margins


Book Description

This world atlas presents a comprehensive overview of the gas-hydrate systems of our planet with contributions from esteemed international researchers from academia, governmental institutions and hydrocarbon industries. The book illustrates, describes and discusses gas hydrate systems, their geophysical evidence and their future prospects for climate change and continental margin geohazards from passive to active margins. This includes passive volcanic to non-volcanic margins including glaciated and non-glaciated margins from high to low latitudes. Shallow submarine gas hydrates allow a glimpse into the past from the Last Glacial Maximum (LGM) to modern environmental conditions to predict potential changes in future stability conditions while deep submarine gas hydrates remained more stable. This demonstrates their potential for rapid reactions for some gas hydrate provinces to a warming world, as well as helping to identify future prospects for environmental research. Three-dimensional and high-resolution seismic imaging technologies provide new insights into fluid flow systems in continental margins, enabling the identification of gas and gas escape routes to the seabed within gas hydrate environments, where seabed habitats may flourish. The volume contains a method section detailing the seismic imaging and logging while drilling techniques used to characterize gas hydrates and related dynamic processes in the sub seabed. This book is unique, as it goes well beyond the geophysical monograph series of natural gas hydrates and textbooks on marine geophysics. It also emphasizes the potential for gas hydrate research across a variety of disciplines. Observations of bottom simulating reflectors (BSRs) in 2D and 3D seismic reflection data combined with velocity analysis, electromagnetic investigations and gas-hydrate stability zone (GHSZ) modelling, provide the necessary insights for academic interests and hydrocarbon industries to understand the potential extent and volume of gas hydrates in a wide range of tectonic settings of continental margins. Gas hydrates control the largest and most dynamic reservoir of global carbon. Especially 4D, 3D seismic but also 2D seismic data provide compelling sub-seabed images of their dynamical behavior. Sub-seabed imaging techniques increase our understanding of the controlling mechanisms for the distribution and migration of gas before it enters the gas-hydrate stability zone. As methane hydrate stability depends mainly on pressure, temperature, gas composition and pore water chemistry, gas hydrates are usually found in ocean margin settings where water depth is more than 300 m and gas migrates upward from deeper geological formations. This highly dynamic environment may precondition the stability of continental slopes as evidenced by geohazards and gas expelled from the sea floor. This book provides new insights into variations in the character and existence of gas hydrates and BSRs in various geological environments, as well as their dynamics. The potentially dynamic behavior of this natural carbon system in a warming world, its current and future impacts on a variety of Earth environments can now be adequately evaluated by using the information provided in the world atlas. This book is relevant for students, researchers, governmental agencies and oil and gas professionals. Some familiarity with seismic data and some basic understanding of geology and tectonics are recommended.




East Greenland Caledonides


Book Description