Making sure of one's ventifacts

Geological terms are creeping into our everyday language. From insects trapped in amber (a mineral formed from fossilised resin) to dinosaurs (a general term for the orders Saurischia and Ornithischia, subclass Archosauria, class Reptilia which dominated the terrestrial ecology of the Mesozoic, many of which achieved great size) - both encountered in Jurassic Park - geology has found a home in popular culture.

The New Penguin Dictionary of Geology by Philip Kearey is a "user friendly" paperback with definitions for 7,606 geological terms. The definitions (typified by the two given above for amber and dinosaur) are concise but informative and are often cross-referenced. Practising geologists, academics, students and pupils of geology would find the dictionary helpful.

Terms are listed in alphabetical order in bold type with two columns to the page and about 20 entries per page. Definitions vary in length and complexity but are written in plain English rather than jargon whenever possible and with cross-referenced terms in italics. The paper is of reasonable quality given the Pounds 6.99 cover price. This works out at almost 11 definitions for a penny - good value by any reckoning.

As with any other type of dictionary or encyclopedia you do not want most of the terms but you do want to be able to find a particular term quickly and easily. This dictionary is not large enough to hold every term that every geoscientist might wish to look up. The subject is so vast that the dictionary would be unmanageable if it was to include all terms and the text would become uncomfortably small. This is a compromise with perhaps too many mineral names and not enough emphasis on some sections of modern geology.

Modern geology encompasses aspects of physics, astronomy, chemistry, biology and mathematics. We are now familiar with terms like global warming, ice age and the ozone hole, with the threat of volcanic eruptions, tsunamis and earthquakes. These are all geoscience issues and the geologist's vocabulary has expanded where overlaps with other sciences have developed.

A very grey area exists where it is difficult to decide whether a term is "geological" or not. For example there are numerous "biological" terms used by the palaeontologists who study ancient organisms, and "environmental", "geographical" and "physical" terms used by the other kinds of palaeos working on the environment, ecology, botany, climatology.

These are just a few of the subject studied by geoscientists. Our knowledge of planetary geology - the science of other planets and moons in our solar system - is also being studied by earthbound geoscientists, although the dictionary has limited reference to terminology from this quarter.

After the last definition, that of zweikanter (a ventifact - an object modified in shape by the wind with two curved surfaces intersecting at a sharp edge), there follow 14 pages of bibliography on general reading, economic geology, engineering geology and hydrogeology, geochemistry, geomorphology, geophysics, mineralogy, crystallography, palaeontology, petrology, igneous and metamorphic plate tectonics, sedimentology, stratigraphy, structural geology and geodynamics and finally volcanology. Several classic texts appear under each heading, given with a full reference, and although some of the texts are out of print or have been superseded by newer works, it is a very useful compilation.

Hazel Rymer is a Royal Society research fellow, Open University.