The Hagendorf Pleystein Province The Center Of Pegmatites In An Ensialic Orogen

This book will broaden readers’ understanding of pegmatites in a special geodynamic setting, dealing with the emplacement of the Hagendorf-Pleystein Pegmatite Province (HPPP) in the Central European Variscides. This treatise illustrates the complex processes leading to the formation and partial destruction of the pegmatites, documenting the geochronological, chemical, mineralogical, geological and geomorphological / sedimentological data set. The book starts with a detailed account of the economic geology of the various pegmatites, explaining why these deposits are a major resource of ceramic raw materials. In its concluding section, a model of the pegmatite evolution in an ensialic orogen provides meaningful insights into the genetic aspects of pegmatite generation. The Late Paleozoic rare-element pegmatites of the HPPP, Oberpfalz-SE, Germany, rank among the largest concentrations in Europe. The biggest pegmatite of this mining district totals 4.4 million tons of ore (Hagendorf-South). The mining history of the HPPP is restricted to the 20th century, when local entrepreneurs started mining operations in search of ceramic raw materials, feldspar and quartz. Today the “Silbergrube Aplite” is still worked for feldspar. The traditional mining of pegmatitic and aplitic rocks in Central Europe, such as the Bohemian Massif, which is shared by Germany, the Czech Republic, Poland and Austria, has been focused on these industrial minerals. In addition to these major commodities, lithium was mined for a period of time. But even today many of these pegmatites of calc-alkaline affiliation have not lost their appeal to mineralogists and mineral enthusiasts for their wealth of minerals that contain P, Nb, Ta, Li, Be, B, U, Th, Sc, Ti and Sn. The most favorable crustal section to bring about pegmatitic rocks of this type, encompassing pegmatoids, metapegmatites, reactivated pseudopegmatites and pegmatites sensu stricto is the ensialic orogen, exemplified by the Variscan (Hercynian) Orogen, which geodynamically connects the Paleozoic pegmatite provinces in North America and Europe. The geological history of the HPPP, however, goes much further than the Carboniferous-Permian magmatic activity, when the last structural disturbances of the Variscan orogeny affected the NE-Bavarian Basement between 450 and 330 Ma. During this time mafic magmatic rocks together with calcareous and arenaceous sediments were converted into paragneisses, calcsilicate rocks, and amphibolites. It is the period of time when tectonic shortening led to over thrusting and when the emplacement of nappes and the architectural elements of the ensialic orogen began taking shape. During the Late Permian, the Mesozoic and the Cenozoic, the HPPP did not lie idle in geological terms; hypogene and supergene alteration continued and found its most recent expression in alluvial-fluvial “nigrine” placer deposits, which resulted from the unroofing of the pegmatites and aplites in the HPPP and can be used even outside HPPP as an ore guide to pegmatites.

Rare Earth Elements (REE) as well as tantalum and niobium are of tremendous importance because of their specific high-technology applications. The contributions gathered in this volume give an up-to-date survey on the mineralogy, primary ore deposits, prospecting, processing and applications of REE, Ta, and Nd, making this volume a useful handbook for practitioners and students. Finally, the comprehensive coverage of the fundamental aspects, especially as regards REE as tracers of geological phenomena, will prove extremely helpful.

The book will include contributions of the state of the art of quartz raw materials (deposits and properties) and their analytics. The chapters are presented by leading scientists in the quartz field. The presentations cover the main interrelations between genesis of quartz - formation of specific properties - analytics - industrial applications of SiO2 raw materials.

Developments in Geotectonics, 10: The Expanding Earth focuses on the principles, methodologies, transformations, and approaches involved in the expanding earth concept. The book first elaborates on the development of the expanding earth concept, necessity for expansion, and the subduction myth. Discussions focus on higher velocity under Benioff zone, seismic attenuation, blue schists and paired metamorphic belts, dispersion of polygons, arctic paradox, and kinematic contrast. The manuscript then ponders on the scale of tectonic phenomena, non-uniformitarianism, tectonic profiles, and paleomagnetism. Concerns cover global paleomagnetism, general summary of the tectonic profile, implosions, fluid pressures, pure shear, crustal extension, simple shear with horizontal axis, geological examples of scale fields, and length-time fields of deformation. The publication explores the cause of expansion, modes of crustal extension, and rotation and asymmetry of the earth, including dynamic asymmetry, precessions, nutations, librations, and wobbles at fixed obliquity, variation of rate of rotation, and categories of submarine ridges. The text is a dependable source of data for researchers wanting to study the concept of expanding earth.

Our aim in writing this book is to try to show how igneous rocks can be persuaded to reveal some ofthe secrets of their origins. The data of igneous rocks consist of field relations, texture, mineralogy, and geochemistry. Additionally, experimental petrology tells us how igneous systems might be expected to behave. Working on this material we attempt to show how hypotheses concerning the origins and evolution of magmas are proposed and tested, and thus illuminate the interesting and fundamental problems of petrogenesis. The book assumes a modest knowledge of basic petro graphy, mineralogy, classification, and regional igneous geology. It has a role complementary to various established texts, several of which are descriptively good and give wide coverage and evaluation of petrogenetic ideas in various degrees of detail. Existing texts do not on the whole, however, deal with methodology, though this is one of the more important aspects of the subject. At first sight it may appear that the current work is a guidebook for the prospective research worker and thus has little relevance for the non-specialist student of geology. We hope this will prove to be far from the case. The methodological approach has an inherent interest because it can provide the reader with problems he can solve for himself, and as an almost incidental consequence he will acquire a satisfying understanding.

This volume brings together a collection of papers that summarize current ideas and recent progress in the study of granite-related mineralization systems. They provide a combination of field, experimental and theoretical studies. Papers are grouped according to the main granite-related ore systems: granite-pegmatite, skarn and greisen-veins, porphyry, orogenic gold, intrusion-related, epithermal and porphyry-related gold and base metal, iron oxide-copper-gold (IOCG), and special case studies. The studies provide a broad spread in terms of both space and time, highlighting granite-related ore deposits from Europe (Russia, Sweden, Croatia and Turkey), the Middle East (Iran), Asia (Japan and China) and South America (Brazil and Argentina) and spanning rocks from Palaeoproterozoic to Miocene in age.