Patterns of Change in Earth Evolution: Report of the Dahlem Workshop on Patterns of Change in Earth Evolution Berlin 1983, May 1-6

ISBN-13: 9783642693199 / Angielski / Miękka / 2011 / 434 str.

H. D. Holland; A. F. Trendall; K. S. Deffeyes

Opis

3 of the experience of the last few generations. The group of happily unexperienced events includes large bolide impacts with the Earth. The evidence for the occurrence of such impacts at intervals of some tens of millions of years is quite convincing, and Lyell stands admonished by Hamlet: "There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy. " The role of bolide impacts on the history of life during other portions of the Phanerozoic Eon is less clear (see Raup and Fischer, both this volume), and catastrophic changes unrelated to extraterrestrial processes may have been important (see Holser, this volume). Changes in the later Precambrian biota are still difficult to interpret, in part because the preservation of soft-bodied animals from this period of Earth history is so unusual (see Seilacher, this volume). During the past billion years or so, bolide impacts have exerted a significant effect on the Earth's surface and its inhabitants, but not on its interior. The 3800 Ma rocks at Isua in West Greenland are the oldest terrestrial rocks that are currently available for inspection (see Dymek, this volume). They contain abundant evidence for the operation of chemical and physical processes that are similar to those of the present day. This situation could not have prevailed during the entire 700 Ma preceding the formation of the Isua rocks.

Spis treści

Evolutionary Radiations and Extinctions.- Large Body Impacts Through Geologic Time.- Sudden Changes in Atmospheric Composition and Climate.- Geochemical Markers of Impacts and of Their Effects on Environments.- The Possible Influences of Sudden Events on Biological Radiations and Extinctions Group Report.- Changes in Sea Level.- Gradual and Abrupt Shifts in Ocean Chemistry During Phanerozoic Time.- Biological Innovations and the Sedimentary Record.- Late Precambrian and Early Cambrian Metazoa: Preservational or Real Extinctions?.- Short-term Changes Affecting Atmosphere, Oceans, and Sediments During the Phanerozoic Group Report.- Patterns and Geological Significance of Age Determinations in Continental Blocks.- The Archean/Proterozoic Transition: A Sedimentary and Paleobiological Perspective.- The Archean-Proterozoic Transition As a Geological Event - A View from Australian Evidence.- Events on a Time Scale of 107to 109Years Controlled by Tectonism or Volcanism.- Time and Space Scales of Mantle Convection.- Isotopic Evolution of the Crust and Mantle.- Degassing of the Earth.- Supracrustal Rocks, Polymetamorphism, and Evolution of the SW Greenland Archean Gneiss Complex.- Geothermal Gradients Through Time.- Variation in Tectonic Style with Time: Alpine and Archean Systems.- Variation in Tectonic Style with Time (Variscan and Proterozoic Systems).- The Long-term Evolution of the Crust and Mantle.- List of Participants.- Author Index.