References

3
Role of Microorganisms
in Wear Down of Rocks and Minerals
Anna A. Gorbushina 1 ,W.E.Krumbein 1
1
Rock Weathering or Rock Wear Down?
Rock weathering is an awkward term. Near and below the Earth’s surface,
physical and chemical processes operate under direct or indirect control of
living matter. Weathering, however, strongly relates to physical and chemical
changes produced by the weather and its long-term average, the climate.
Meteorological connotation of the term ignores the importance of biological
interactions in the process of rock and material alteration. Terms like
biotransfer, biocorrosion, biodeterioration, bioabrasion, bioerosion, biodenudation,
or biokarst closely connect the physical and chemical processes
related to mineral and rock destruction with biological phenomena and
processes, as indicated by the prefix. Therefore, in this chapter, it was deliberately
decided to avoid the term rock weathering as much as possible.
Krumbein and Dyer (1985) suggested dividing the processes of rock and
mineral destruction into physical and chemical transfer reactions. Physical
transfer includes biological and abiological processes through which
particles are mechanically disconnected from a bulk material and transferred
into the hydrosphere, atmosphere or pedosphere as particulates,
colloids and aerosols. Chemical transfer embraces all biologically or abiologically
driven reactions through which ions are removed from rock
and mineral and transformed into gases, solutes, colloids. It can also yield
solid particles after precipitation of intermediate gaseous or liquid compounds.
Krumbein (1969, 1988, 1993, 1996, 1998) and Krumbein and Dyer (1985)
described the physical and chemical biotransfer actions in an embracing
definition, which introduces “wear down” as a generalized term. In a geological
context, wear down was perhaps used for the first time in 1885
concerning sponge spicules transformed into powder. The original use of
this term, however, stems from 1729. It described the weight loss of silver
coins due to use and exposure to environmental conditions.
1 AG Geomikrobiologie, ICBM, Carl von Ossietzky Universität, Postfach 2503, 26111 Oldenburg,
Germany, e-mail: a.gorbushina@uni-oldenburg.de, Tel: +49-441-7983393, Fax: +49-
441-7983384
Soil Biology, Volume 3
Microorganisms in Soils: Roles in Genesis and Functions
(ed. by F. Buscot and A. Varma)
c○ Springer-Verlag Berlin Heidelberg 2005