Developments in Petrology 11A, Volume A: Kimberlites I: Kimberlites and Related Rocks covers the proceedings of the Third International Kimberlite Conference, held in Clermont Ferrand, France in September 1982. Separating 75 papers into three parts and 28 chapters, this volume focuses on Western Australian lamproites and kimberlites. Significant chapters are also devoted to Alpine type ultramafic bodies. The occurrence, detection, geology, petrology, and synthesis of these precious rocks are discussed. Other general topics covered include diatremes, diamonds, and mantle sample.
This is a book about the petrology of kimberlites. It is not about upper mantle xenoliths, diamonds, or prospecting for kimberlites. The object of the book is to provide a comprehensive survey and critique of the advances which have been made in kimberlite studies over the last twenty-five years. Kimberlites are rare rock types; however, their relative obscurity is overriden by their economic and petrological importance to a degree which is not shared with the commoner varieties of igneous rocks. Kimberlites are consequently of interest to a diverse group of earth scientists, ranging from isotope g~ochemists concerned with the evolution of the mantle, to volcanologists pondering the origins of diatremes, to exploration geologists seeking new occurrences of the diamondiferous varieties. A common factor essential to all of these activities is a thorough understanding of the characteristics of kimberlites. For the petrologist, kimberlites are exciting and challenging objects for study. Their petrographic diversity, complex mineralogy and geochemistry, and unusual style of intrusion provide endless opportunities for stimulating hypothesis and conjecture concerning their origin and evolution. Kimberlites are a part of a wide spectrum of continental intra-cratonic magmatism. Only by understanding all of the parts of this activity in detail may we make progress in our understanding of the whole.
This remarkable volume presents the first revision to the classification system of diamond-bearing rocks in over eighty years. Presenting the latest mineralogical data, this book offers a detailed description of the mineralogy and geochemistry of kimberlites, orangeites, and lamproites. Several hundred new analyses of minerals in orangeites are included. This volume follows the publication of Kimberlites, by R.H. Mitchell, and Petrology of Lamproites, by R.H. Mitchell and S.C. Bergman, concluding the trilogy.
High-Pressure Research: Applications in Geophysics contains the papers presented during a U.S.-Japan joint seminar held in Honolulu, Hawaii, 6-9 July 1976. The seminar brought together scientists engaged in high pressure-high temperature research to exchange ideas on the latest state-of-the-art developments, their experimental results, and their latest interpretations with regard to the significance of these results to the geophysical sciences in general. Four formal sessions were held. Of the forty-two papers presented at the seminar, thirty-nine appear as contributed papers and three as abstracts in this volume. The papers in Session I examine the geophysics and geochemistry of the crust and upper mantle. The contributions in Session II focus on phase transitions related to Earth's deep interior. Session III is devoted equations of state and shock wave experiments while Session IV covers instrumentation, pressure calibration, and standardization.
Featuring over 250 contributions from more than 100 earth scientists from 18 countries, The Encyclopedia of Igneous and Metamorphic Petrology deals with the nature and genesis of igneous rocks that have crystallized from molten magma, and of metamorphic rocks that are the products of re-crystallization associated with increases in temperature and pressure, mainly at considerable depths in the Earth's crust. Entries range from alkaline rocks to zeolite facies - providing information on the mineralogical, chemical and textural characters of rock types, the development of concepts and the present state of knowledge across the spectrum of igneous and metamorphic petrology, together with extensive lists of both commonly used and little used terms and bibliographies.
This study documents alkaline rock occurrences in British Columbia; describes their petrography, geochemistry, economic geology, and field relationships; and determines the timing and tectonic controls of emplacement, providing a basis for future, detailed studies. Work was begun in 1984 and included field mapping during the summers of 1984, 1985, and 1986. All the carbonatite-syenite localities (with the exception of the Wicheeda Lake and Mount Bisson showings) and a large number of the diatreme breccias were mapped and sampled.
This book summarizes the geomorphology, geology, geochronology, geophysics and mineral resources of the Congo Basin, one of the world’s most enigmatic and poorly understood major intra-continental sedimentary basins, and its flanking areas of Central Africa. It provides an up to date analysis of the large region’s origin and evolution. The book’s nineteen chapters take the reader through the entire basement history, as well as the Basin’s ca. 700 million years of cover sequences. Starting from its Archean cratons and Proterozoic mobile belts, and proceeding through the Phanerozoic sequences, including the most recent Cenozoic successions, the book also explores the present drainage systems and the subtle but complex topography of the Congo Basin. It also presents and evaluates new basin models and related dynamic processes, as well as revised correlation schemes with its Gondwana counterparts in South America, all of which provide key insights into its rich diamond deposits and other mineral wealth, which are documented in the final chapters. A specific feature of this book is its synthesis, performed by teams of active experts, of a vast amount of geoscientific data previously only recorded in research reports, company reports, survey bulletins, and scattered journal articles and books. The sheer size of the Congo Basin (ca.1.8 million km2, or just under half the area of the EU) and Central Africa (some 7 million km2, or more than 70% of the area of the USA) will make this a sought-after source of information and inspiration on this unique region.
Volume 2, dedicated to Barry Hawthorne, presents papers concerned with the genesis of eclogites, the mineralogy of diamond and its inclusions, exploration methods for kimberlite, the geochemistry of the upper mantle and the character of cratons.
Given the established nature of geoscientific knowledge of the Kaapvaal craton compared to the Slave craton, and given the exciting new interdisciplinary results coming from the Kaapvaal Project and from Slave craton studies, scientists working on both cratons were brought together in a workshop to compare and contrast the nature of these two cratons. Of the 54 papers presented at the workshop, 24 are included in this volume. There are clearly major similarities and differences between these two Archean cratons. The crust of both was predominantly formed in the Mesoarchean. Both contain crustal sections consisting of terranes of different ages welded together by Archean accretionary events. Both crustal sections are underlain by lithospheric mantle sections consisting of peridotites that experienced extensive partial melt extraction between 2.9 Ga and 3.2 Ga, but this is where the similarities between the cratons end. One of the most striking differences between the Slave and Kaapvaal cartons is the apparent seismic homogeneity of the Kaapvaal craton's SCLM whereas the Slave craton is seismically layered. The seismic layering in the centre of the craton correlates laterally and with depth with electrical layering and geochemical layering. Taken together, these differences suggest that SCLM formation was different for the two cratons, implying that the search for a single causative formation process is bound to fail. Reprinted from the journal Lithos Volume 71, numbers 2-4.
