Geoscience Reference
In-Depth Information
fossils, and it is reasonable to say that by then the science of palae-
ontology had begun. In France, Georges Baron Cuvier championed
palaeontological research and produced many important papers
including his celebrated Description ge´ologique des environs de
Paris, co-authored with Alexandre Brongniart (1770-1847) in 1822.
In it they described the Tertiary deposits of the Paris Basin, and, as
Martin Rudwick pointed out in 1997, used the fossils as indicators of
palaeoecological conditions rather than strict stratigraphical tools as
William Smith had. In his Strata Identified by Organized Fossils,
Containing Prints on Coloured Paper of the Most Characteristic
Specimens in Each Stratum, published in four parts (of a projected
seven) between 1816 and 1819, and Stratigraphical System of
Organized Fossils, which appeared in 1817, Smith recognised two
fundamental principles: that successive rock sequences were charac-
terised by differing fossil assemblages, and that a stratum found
beneath another is younger unless it is shown to have been over-
turned. These principles allowed for the easy determination of the
relative age or position of strata through an inspection of its contained
fossils. They paved the way for the development of biostratigraphy -
the study of rock sequences based on the fossils that they contain.
In Strata Identified by Organized Fossils, each part (priced at
7 shillings and 6 pence) consisted of a number of pages of explanatory
text that preceded between three and five plates. Each plate depicted a
series of fossils from a particular horizon printed on a background
colour that represented the colour of the lithology in which they were
found (Figure
9.2
). This was an ingenious method of palaeontological
colour coding, and the colour coincided with those used on his great
map of 1815. The accompanying text for each illustration gives the
name of the horizon such as the 'Upper Chalk' or 'Fuller's Earth
Rock'; the nature of soil that developed on top of it; notes on the purity
or otherwise of groundwater found associated with it; and it lists the
illustrated fossils and the localities fromwhere they were collected. He
noted that Suffolk contained some of the worst land in the country on
account of the presence of blown sand, and that shelly deposits occurred
