New Perspectives on the Caledonides of Scandinavia and Related Areas


Book Description

The Caledonides are a major orogenic belt that stretches from the Arctic, through Scandinavia, East Greenland, Britain and Ireland into the Atlantic coast of North America. Following the break-up of Rodinia, the Caledonides formed in the Palaeozoic by the drifting of various continents and their eventual aggregation in the Silurian and Devonian. The orogen subsequently fragmented during the opening of the Atlantic Ocean. This volume brings together 25 papers presenting the results of modern research that investigates the orogenic processes and the provenance of specific components of the belt. The contributions reflect different lines of research, linking traditional field studies with modern analytical techniques. In addition three overview papers summarize the main features of the belts in Scandinavia, Svalbard, East Greenland, Britain and Ireland, highlighting the advances made since the last major synthesis of the Scandinavian Caledonides 30 years ago, and discussing important open questions.







Ancient Supercontinents and the Paleogeography of Earth


Book Description

Ancient Supercontinents and the Paleogeography of Earth offers a systematic examination of Precambrian cratons and supercontinents. Through detailed maps of drift histories and paleogeography of each continent, this book examines topics related to Earth's tectonic evolution prior to Pangea, including plate kinematics, orogenic development, and paleoenvironments. Additionally, this book discusses the methodologies used, principally paleomagnetism and tectonostratigraphy, and addresses geophysical topics of mantle dynamics and geodynamo evolution over billions of years. Structured clearly with consistent coverage for Precambrian cratons, this book combines state-of-the-art paleomagnetic and geochronologic data to reconstruct the paleogeography of the Earth in the context of major climatic events such as global glaciations. It is an ideal, up-to-date reference for geoscientists and geographers looking for answers to questions surrounding the tectonic evolution of Earth. - Provides robust paleogeographies of Precambrian cratons based on high-quality paleomagnetic and geochronologic data and critically tested by global geological datasets - Includes links to updated databases for the Precambrian such as PALEOMAGIA and the Global Paleomagnetic Database (GPMDB) - Presents full-color maps of the drift histories of each continent as well as their paleogeographies - Discusses key questions regarding continental drift, the supercontinent cycle, and the geomagnetic dipole hypothesis and analyzes palaeography in the context of Earth's holistic evolution







The Caledonide Orogen


Book Description




The Great Ordovician Biodiversification Event


Book Description

Two of the greatest evolutionary events in the history of life on Earth occurred during Early Paleozoic time. The first was the Cambrian explosion of skeletonized marine animals about 540 million years ago. The second was the "Great Ordovician Biodiversification Event," which is the focus of this book. During the 46-million-year Ordovician Period (489–443 m.y.), a bewildering array of adaptive radiations of "Paleozoic- and Modern-type" biotas appeared in marine habitats, the first animals (arthropods) walked on land, and the first non-vascular bryophyte-like plants (based on their cryptospore record) colonized terrestrial areas with damp environments. This book represents a compilation by a large team of Ordovician specialists from around the world, who have enthusiastically cooperated to produce this first globally orientated, internationally sponsored IGCP (International Geological Correlation Program) project on Ordovician biotas. The major part is an assembly of genus- and species-level diversity data for the many Ordovician fossil groups. The book also presents an evaluation of how each group diversified through Ordovician time, with assessments of patterns of change and rates of origination and extinction. As such, it will become the standard work and data source for biotic studies on the Ordovician Period.




Neoproterozoic Geobiology and Paleobiology


Book Description

This volume presents a sample of views and visions among some of the growing numbers of Neoproterozoic workers. It includes a set of multidisciplinary reviews on the Neoproterozoic fossil record, evolutionary developmental biology of animals, and molecular clock estimates of phylogenetic divergences. These topics are of continuing interest to geoscientists and bioscientists who are intrigued by the deep history of the Earth and its inhabitants.




The Dawn of Animal Life


Book Description

This 1985 book examines the origin of the present diversity of marine invertebrate animals. A brief review of the early stages in the history of life discusses the time-scale of the relevant geological periods alongside corresponding events in the evolutionary sequence. These views of the early history of life are then matched against the fossil record and conjectures drawn from the living fauna, enabling the author to attempt an overview of the early diversification of marine animal life. Transitions to the succeeding assemblages of shellbearing fossils in Palaeozoic rocks are discussed and a number of stratigraphic adjustments are suggested for the period in which evolutionary events had their greatest impact on oceans and marine rock strata. The need for an interdisciplinary approach to early evolution is emphasized.




The Caledonide Geology of Scandinavia


Book Description

work on structural and stratigraphic relationships is presented from various parts of the mountain belt. In the first paper of the section, R. O. Greiling (Heidelberg) describes the Middle Allochthon of Vasterbotten, northern Sweden, where tectonic windows through the Upper Allochthon (Seve Nappe) show that the Middle Allochthon has a similar lithostratigraphy to that of the Stalon Nappe Complex of the eastern Caledonian margin but with a more ductile deformation and metamorphosed to a higher grade following thrust emplacement. These relations are explained by suggesting that the window rocks were initially subducted beneath a colliding western plate but were later accreted to the base of the western plate and thrust with it. The thrust geometry of the windows, described as antiformal stacks, agrees with this model. The Middle Allochthon of the Caledonian margin in northern Sweden is described by R. O. Greiling and R. Kumpulainen (Heidelberg and Stockholm) who record two distinct metasedimentary units separated by a thick zone of mylonites interpreted as a lateral thrust ramp. Turbidites in the northern unit were derived from an unidentified igneous source to the east and cannot be correlated with other sequences in the Middle Allochthon. In another paper dealing with the northern Swedish Caledonides, L. Hansen (Uppsala) describes down-to-the-west normal faults cutting the autochthonous Cambrian sediments in the tunnel sections of the Vietas Hydropower Station, but themselves being truncated by the basal decollement of the Lower Allochthon.