الصفحة 1
الصفحة 1
Neoproterozoic Geobiology and Paleobiology
The Neoproterozoic Era (1000-542 million years ago) is a geological period of dramatic climatic change and important evolutionary innovations. Repeated glaciations of unusual magnitude occurred throughout this tumultuous interval, and various eukaryotic clades independently achieved multicellularity, becoming more complex, abundant, and diverse at its termination. Animals made their first debut in the Neoproterozoic too. The intricate interaction among these geological and biological events is a centrepiece of Earth system history, and has been the focus of geobiological investigations in recent decades. The purpose of this volume is to present a sample of views and visions among some of the growing numbers of Neoproterozoic workers. The contributions represent a cross section of recent insights into the field of Neoproterozoic geobiology.
High-Latitude Bioerosion : The Kosterfjord Experiment
Bioerosion is the major force driving the degradation of marine skeletal carbonates and limestone coasts. A wide spectrum of mechanical and/or chemical boring, scraping or crushing organisms break down calcereous substrates, comprising various grazers, macroborers and especially microborers. Their traces on and within hard substrates are known from fossil carbonates as old as the Precambrian and serve as valuable palaeoenvironmental indicators. Bioerosion processes have been extensively studied in tropical seas, while corrsponding investigations from cold-temperate to polar settings remain sparse. For the first time, an experimental study yields insight into the pace of carbonate degradation and the chronology of boring community development along a bathymetric gradient in a high-latitude setting.
From Suns to Life: : A Chronological Approach to the History of Life on Earth
This review emerged from several interdisciplinary meetings and schools gathering a group of astronomers, geologists, biologists, and chemists, attempting to share their specialized knowledge around a common question: how did life emerge on Earth? Their ultimate goal was to provide some kind of answer as a prerequisite to an even more demanding question: is life universal? The main chapters of this review present the formation and evolution of the solar system (3); the building of a habitable planet (4); prebiotic chemistry, biochemistry, and the emergence of life (5); the environmental context of the early Earth (6); and the ancient fossil record and early evolution (7). The concluding chapter (9) provides the highlights of the review and presents the different points of view about the universality of life. Two pedagogical chapters are included; one on chronometers (2), another in the form of a "frieze" (8) which summarizes in graphical form the present state of knowledge about the chronology of the emergence of life on Earth, before the Cambrian explosion.
Cephalopods Present and Past : New Insights and Fresh Perspectives
Cephalopods are diverse, highly developed molluscs capable of swimming and jet propulsion. These animals are an important component of present-day marine ecos- tems throughout the world and comprise approximately 900 species. They also have an extraordinary fossil record, extending back to the Cambrian Period, with as many as 10,000 extinct species. Throughout their long history, they have experienced sp- tacular radiations and near-total extinctions. Because of their superb fossil record, they also serve as ideal index fossils to subdivide geologic time. This book touches on many of these themes, and it treats both fossil and present-day cephalopods.
Antarctica : Contributions to Global Earth Sciences
Sixty articles arranged in eight thematic sections refer to most recent geological and geophysical results of Antarctic research. The Precambrian of the East Antarctic shield and its geological history is considered as well as sub-ice topography, geophysics and stratigraphy, sedimentology and geophysics of the surrounding Southern Ocean. Particular emphasis is given to the connection of the Antarctic and the surrounding continents when forming part of Gondwana.
