Dictionary of Geology

Introduction

This dictionary contains 7703 entries which cover definitions of terms relevant to Geology. Because of the overlap which exists between the many branches of the Earth Sciences, for example between Geomorphology and Sedimentology or Palaeontology and Biology, some of the entries might be considered to be at the borders of Geology, but are included because of their importance to the subject.

For reasons of economy of space, I have concentrated on producing concise definitions of the entries rather than longer treatments. If further information should be required about any particular entry, it should be sought from the 432 references, arranged by topic, provided in the Bibliography, which lists modern works covering all aspects of Geology.

Also for reasons of space, I have omitted descriptions of individual geologists. Similarly, it would have been impossible to include definitions of, for example, every mineral ever described, every small local glacial event or every local stratigraphy. I hope that the reader will agree that I have selected the most important.

Entries and synonyms are distinguished by bold type, whilst those words which appear in the entries and are entries themselves appear in small capitals. Cross references to related terms are labelled 'See also' and references to contrasting terms are labelled 'Cf'. Abbreviations used in the text are as follows: Ma = million years, Ga = billion (10") years, L. = Lower, M. = Middle, U. = Upper, ~ = approximately.

Spelling in most cases follows the conventions used in Great Britain. Some, but not all, alternative spellings are given in American usage. Alternatives have not always been given for words containing once-ligatured diphthongs, e.g. 'ae'. I hope that this will not seriously inconvenience foreign readers.

All stratigraphic ages are given according to Harland, W. В., Armstrong, R. L., Cox, A. V., Craig, L. E., Smith, A. G. and Smith, D. G. (1990) Л Geologic Timescale 1990, Cambridge University Press, Cambridge. A stratigraphic column, together with explanations of SI, cgs and imperial units, abbreviations used for very small and nery large numbers, unit conversions, and facts about the Earth, will be found in the Appendix.

I would welcome suggestions for the inclusion of terms which do not appear in the present dictionary.

In this second edition I have taken the opportunity to add terms that did not appear in the first edition and to correct a few typographical errors. There are now almost a hundred new entries in this new edition, and the bibliography has been expanded.

Philip Kearey Bristol, October 2000