Geoscience Reference
In-Depth Information
English geological establishment. Perhaps also Smith's period of
imprisonment for debt did not help his advancement. Nor did it help
that in 1819 the Geological Society published a large-scale geological
map of England and Wales which was remarkably similar to his 1815
map. This 1819 map was prepared by George Bellas Greenough
(1778-1855), one of the society's leading lights and its first President.
Towards the end of his life Smith received two geological accolades,
one of which, the award of a Wollaston Medal by the Geological
Society, must have seemed somewhat ironic to him. The second
honour must have given Smith some pleasure: the conferring of an
honorary degree in law, not by an English university, but by Trinity
College Dublin, during the 1835 meeting of the British Association for
the Advancement of Science, which was held outside mainland
Britain for the first time that year.
Smith's two ground-breaking geological laws were the Principle
of Superposition, and the Law of Strata identified by fossils, both of
which were formulated in his publication Strata Identified by Fossils,
published in four parts between 1816 and 1819. The first Law said that
in a sequence of beds of rock, those that lie on top are younger than
those below, unless there is clear evidence to suggest that the whole
succession has been overturned. Such reversal could be caused by
folding and/or faulting of the rocks. Smith's second Law said that
each bed contained a distinctive fossil assemblage. These ideas were
important as they allowed geologists to appreciate the original geo-
metry of geological successions, and also to be in a position to correlate
horizons for long lateral distances even if there was a break in the
outcrop of that horizon on the surface. In terms of drawing geological
maps, these laws were fundamental, and an understanding of them
made the task simpler.
CHARLES LYELL
Charles Lyell came of quite different stock from Smith. Born in the
family seat Kinnordy House, close to Forfar in Scotland, the centre of
an estate that is still in the Lyell family, the young Charles divided his
