These pages were designed and constructed by Dr Jonathan Jeffery in June 1999; the contents of are © Dr J.E. Jeffery unless otherwise stated. Many thanks to the British Geological Survey for permission to use the image of BGS GSL 1527, and to the Trustees of the National Museum of Scotland for permission to use the image of NMS G 1911.62.9567.

Although every effort is made to ensure that the information contained on this web site is accurate and up to date, I do not guarantee its accuracy. Anyone using the information does so at their own risk and shall be deemed to indemnify me from any injury or damage arising from such use. Readers should verify information independently before relying on it. Any views and opinions expressed in these pages are my own, and must not be considered to the official opinion or policy of University College London. Any comments or complaints about this site should be addressed to Dr J.E. Jeffery in the first instance.