The Ore Minerals Of The Ilimaussaq Intrusion

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.

reviewers, and reported by users of the earlier This third edition (or issue) of the Quantitative Data File for ore minerals (QDF) of the Commission on editions. The result is that 510 species and 125 are Mineralogy of the International Mineralogical compositional or structural variants, or varieties, of Association (COM-IMA) is published, with the species, are represented in QDF3. A large number of support of the Natural History Museum, London, by the entries include data collected from the type Chapman & Hall. It has been greatly revised and specimen of a mineral: these include data extracted enlarged and now includes graphs of the reflectance from the published literature. In this respect, QDF3 spectra for all of its entries. These have been differs from earlier editions. included in response to requests from users of the We have also revised and simplified the notes earlier editions. Also included, for those users concerning X-ray data: no longer are the strongest unfamiliar with the application of such spectra to lines in the powder diffraction pattern quoted, nor mineral identification, are introductory notes, are cell dimensions generally given. Instead, it was illustrated with examples of R spectra. decided to refer to data from the original description, The 635 data sets, which are arranged or to data in the PDF of the JCPDS.

This volume represents an edited selection of papers presented at the International symposium on the geology of tin deposits held in Nanning City in October 1984. It documents a great advance in our knowledge of tin deposits, particularly of the People's Republic of China. Details are presented in English for the first time on the major tin-polymetallic sulphide deposits of Dachang and Gejiu, which bear similarities to the deposits of Tasmania, but are little known to the geological community outside of China. The publication of this volume was sponsored by the United Nations ESCAP Regional Mineral Resources Development Centre (RMRDC), now a Regional Mineral Resources Development Project (RMRDP) within ESCAP. The Centre had previously published a report on the Symposium in Nanning City and the following field trip to the Dachang tin-polymetallic sulphide deposit of Guangxi, entitled "Report on the International Symposium on the Geology of Tin Deposits: Nanning and Dachang, China, 27 October - 8 November 1984". It is my privilege to acknowledge the help provided by Dr. J. F. McDivitt and Dr. H. W. Gebert, co-ordinator of ESCAP-RMRDC.