‘sugar’ helps the silica go down
bacteria which manage to survive the intense temperatures
and hostile environment of hot volcanic springs, may help
us to understand the formation of rock deposits containing
some of the earliest records of life on Earth.
Liane G Benning, of Earth Sciences, has received a Leverhulme
Trust grant of £93,390 over 3 years, to research the formation
of silica which build up into rock formations surrounding
hot springs. Laboratory experiments attempting to duplicate
hot spring environments have produced similar deposits,
but they form tens to hundreds of times slower than those
found in nature.
rocks – Dr Liane G Benning with examples of deposits taken
from hot springs in the Taupo volcanic region of New Zealand
is believed that this difference may be due to the activity
of microbes, mostly cyanobacteria, which are protected
from the chemical and environmental conditions in the
springs by a sheath made up of various sugar components,
or polysaccharides. The silica appears to form on these
sheaths, but the precise role of the microbes and their
‘sugar coating’ in starting and enhancing silicification
has not been determined.
a flow-through system at temperatures between 25 and 600C
to simulate a hot spring environment, Dr Benning and colleague
Dr Kurt Konhauser will mimic the process in the laboratory,
allowing them to study the mechanisms and processes of
silica formation in relation to the cyanobacteria.
research has a variety of applications," said Dr
Benning. "In many countries, the heat from hot springs
is used as an energy source, but deposits of silica can
often cause problems by blocking pipes and conduits.
silicification process is also linked to the formation
of ore deposits, which provide important economic resources.
In addition, understanding at a detailed level how modern
silica forms will help us to understand how ancient siliceous
rocks were formed, such as Precambrian stromalites. These
ancient silica deposits preserve some of the earliest
records of life on Earth."
further information, see the leverhulme