Page 14 - Statistics and Data Analysis in Geology

Mathematical methods have been employed by a few geologists since the
earliest days of the profession. For example, mining geologists and engineers have
used samples to calculate tonnages and estimate ore tenor for centuries. As Fisher
pointed out (1953, p. 3), Lyell’s subdivision of the Tertiary on the basis of the rel-
ative abundance of modern marine organisms is a statistical procedure. Sedimen-
tary petrologists have regarded grain-size and shape measurements as important
sources of sedimentological information since the beginning of the last century.
The hybrid Earth sciences of geochemistry, geophysics, and geohydrology require
a firm background in mathematics, although their procedures are primarily derived
from the non-geological parent. Similarly, mineralogists and crystallographers uti-
lize mathematical techniques derived from physical and analytical chemistry.
Although these topics are of undeniable importance to specialized disciplines,
they are not the subject of this book. Since the spread of computers throughout
universities and corporations in the late 195O’s, geologists have been increasingly
attracted to mathematical methods of data analysis. These methods have been bor-
rowed from all scientific and engineering disciplines and applied to every facet of
Earth science; it is these more general techniques that are OUT concern. Geology
itself is responsible for some of the advances, most notably in the area of mapping
and spatial analysis. However, our science has benefited more than it has con-
tributed to the exchange of quantitative techniques.
The petroleum industry has been among the largest nongovernment users of
computers in the United States, and is also the largest employer of geologists. It
is not unexpected that a tremendous interest in geomathematical techniques has
developed in petroleum companies, nor that this interest has spread back mto the