Origin Of Igneous Rocks

A manuscript copy, with corrections and editor's notations in red, of the article published in the Philosophical Society of Washington Bulletin, volume 12, 1892.

The origin of different kinds of igneous rocks can be understood in terms of their tectonic setting, and by way of the isotope compositions of strontium, neodymium, and lead. This book explains the petrogenesis of igneous rocks as a consequence of tectonic processes resulting from interactions between asthenopheric plumes and the overlying lithospheric mantle. The relevant principles of isotope geochemistry are explained in the first chapter, making it accessible for university students as well as professionals. The relevant isotopic data is presented in diagrammatic form. The book contains more than 400 original drawings.

Developed by three experts to coincide with geology lab kits, this laboratory manual provides a clear and cohesive introduction to the field of geology. Introductory Geology is designed to ease new students into the often complex topics of physical geology and the study of our planet and its makeup. This text introduces readers to the various uses of the scientific method in geological terms. Readers will encounter a comprehensive yet straightforward style and flow as they journey through this text. They will understand the various spheres of geology and begin to master geological outcomes which derive from a growing knowledge of the tools and subjects which this text covers in great detail.

Acknowledgements xix pioneering workers on igneous layering in Greenland xx Wbrkshop participants xxii Henning Sfl!rensen, University of Copenhagen, Dermark. Latte Melchior Larsen, Geological SUrvey of Greenland, Copenhagen, Dermark. Abstract 1 1 • Introduction 1 1. 1 The agpaitic rocks of the Ilimaussaq intrusion 3 2. Igneous layering in the Ilimaussaq intrusion 4 3. Mineralogy of the layered kakortokite series 15 4. Chemistry of the layered kakortokite series 19 5. Origin of the kakortokite layering 20 5. 1 Discussion 22 6. Conclusion 25 References 26 2. I. AYERn«;r CCMPl\CTIOO NID PCBJ. "--MN}tATIC ~ IN '!HE KLOKKEN INTRUSIOO 29 Ian Parsons and SUsanne M. Becker, University of Aberdeen, U. K. Abstract 29 1. Introduction 30 2. Age of the intrusion 31 3. General structure and mineral variation 31 vi TABLE OF CONTENTS 3. 1 Nomenclature of rock types 31 3. 2 Bulk chemical and modal variation 36 4. The contacts and wall-rocks 37 4. 1 Guter contact 37 4. 2 The gabbro sheath 37 4. 3 The unlaminated syenite sheath 39 4. 4 The gabbro-syenite transition 41 5. The layered series 43 5. 1 General relationships 43 5. 2 Granular syenites 43 5. 2. 1 Structure and cryptic variation 43 5. 2. 2 Origin of granular layers 46 5. 2. 3 Trace elements and chamber dlinensions 47 5. 3 Laminated syenites 48 5. 3. 1 General features 48 5. 3. 2 Mineral layering 51 5. 3.