"The history of Earth's early atmosphere, hydrosphere, and biosphere, from Hadean through Proterozoic time, is one of geology's enduring puzzles. Ore deposits provide important insights into this history because they contain elements and minerals that are highly sensitive to the geochemical environment in which they form. Just what these minerals tell us remains a matter of considerable debate, however. When and how did life develop, an oxygen-rich atmosphere form, and sulfate dominate the ocean? This volume contains reports on these questions from both sides of the aisle for iron and manganese formations, uranium paleoplacers and hydrothermal deposits, and exhalative sulfides and oxides."--Publisher's website.

From the first attempts to understand the origin of giant iron ore deposits, numerous false assumptions have been used as the basis of genesis models that have become standard and unquestioned, with later research generally seeking to find evidence supporting the existing models and ignoring contrary evidence. Many models were constructed based on extremely rare features, and their absence in the global abundance of iron formations was not considered important since there was no understanding of the major sedimentary structures, i.e. laminations and banding. Inconsistencies within the hypothetical models are either ignored or excused by proposing special circumstances, but no one considers that the models might be wrong or have only limited application. Many hypotheses regarding Earths history have been postulated from the difference between Phanerozoic and Precambrian iron-formations. In particular, the development of an oxygenated atmosphere has been deduced from the supposed evolution of iron-formations. The subject has provided a fertile field for research and models of Earths history, but without clear knowledge of the sedimentation, diagenesis and metamorphism of BIFs (branded iron formations), such models are speculative or even irrelevant. Since these models on the genesis and distribution of BIF were used as proxies to answer questions regarding the composition of the early oceans and atmosphere, weathering and transport conditions on early land surface, volcanism and continental development in the Archean eon, and as they affect exploration for the largest volume and most basic of industrial metals, they have an importance beyond academic sedimentary and stratigraphic interest. The aim of this book is to present a model for the origin of BIFs and derived high-grade iron ore deposits with global applications that are still subject to correction and change as new information becomes available and are free of illogical assumptions which do not conflict with either field observations or basic chemistry and physics.

Iron-Formation: Facts and Problems

Volume 21 of Reviews in Mineralogy treats a short course on the rare earth elements to about 80 participants in San Francisco, California, December 1-3, 1989, just prior to the fall meeting of the American Geophysical Union. Contents: Cosmochemistry of the Rare Earth Elements: Condensation and Evaporation Processes Radiogenic Isotope Geochemistry of Rare Earth Elements Partitioning of Rare Earth Elements between Major Silicate Minerals and Basaltic Melts An Approach to Trace Element Modeling Using a Simple Igneous System as an Example Rare Earth Elements in Upper Mantle Rocks Rare Earth Elements in Metamorphic Rocks Rare Earth Elements in Sedimentary Rocks: Influence of Provenance and Sedimentary Processes Aqueous Geochemistry of Rare Earth Elements Rare Earth Elements in Lunar Materials Compositional and Phase Relations among Rare Earth Element Minerals Economic Geology of Rare Earth Minerals Cathodoluminescence Emission Spectra of Rare Earth Element Activators in Minerals

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.

Earth as an Evolving Planetary System, Second Edition, explores key topics and questions relating to the evolution of the Earth's crust and mantle over the last four billion years. This updated edition features exciting new information on Earth and planetary evolution and examines how all subsystems in our planet—crust, mantle, core, atmosphere, oceans and life—have worked together and changed over time. It synthesizes data from the fields of oceanography, geophysics, planetology, and geochemistry to address Earth's evolution. This volume consists of 10 chapters, including two new ones that deal with the Supercontinent Cycle and on Great Events in Earth history. There are also new and updated sections on Earth's thermal history, planetary volcanism, planetary crusts, the onset of plate tectonics, changing composition of the oceans and atmosphere, and paleoclimatic regimes. In addition, the book now includes new tomographic data tracking plume tails into the deep mantle. This book is intended for advanced undergraduate and graduate students in Earth, Atmospheric, and Planetary Sciences, with a basic knowledge of geology, biology, chemistry, and physics. It also may serve as a reference tool for structural geologists and professionals in related disciplines who want to look at the Earth in a broader perspective. - Kent Condie's corresponding interactive CD, Plate Tectonics and How the Earth Works, can be purchased from Tasa Graphic Arts here: http://www.tasagraphicarts.com/progptearth.html - Two new chapters on the Supercontinent Cycle and on Great Events in Earth history - New and updated sections on Earth's thermal history, planetary volcanism, planetary crusts, the onset of plate tectonics, changing composition of the oceans and atmosphere, and paleoclimatic regimes - Also new in this Second Edition: the lower mantle and the role of the post-perovskite transition, the role of water in the mantle, new tomographic data tracking plume tails into the deep mantle, Euxinia in Proterozoic oceans, The Hadean, A crustal age gap at 2.4-2.2 Ga, and continental growth