The
tools used to collect fossils are simple ones such as
those used by geologists: hammers, trowels, various cutting
implements, compasses, brushes and sieves.
Fossils sometimes appear on the surface when eroded out
of the soft rock strata around them. In such cases, it
is sufficient to clean the fossils with a brush. However,
fossil collecting is not usually that easy. The rocks
inside which they are concealed are generally very hard,
and it can take hours to extract a fossil from its rocky
matrix. First, it is important to determine from what
point the rock should be broken. Fracture lines are identified
in the light of the rock bed itself. Every type of rock
is broken in different ways. Schists, for example, have
layers through which fracture lines can be established.
Chalk, on the other hand, offers no such layers. At the
same time, it is very important to watch for such indications
as color changes or structural differences, if the fossils
contained inside are not to be damaged.
After
the fossil has been extracted from the rock, it undergoes
a number of different processes. It must be protected
and reinforced while being transported to the laboratory
where it will be examined. One of the methods employed
is to stabilize the fossil with chemical adhesives. Plaster
casts are used for very large fossils. Those parts of
the fossil that will be at risk during transportation
are wrapped in dampened newspaper and then dipped in plaster.
The fossil then must be cleaned in order for all its
details to become visible. If the fossil is harder than
the rock surrounding it, then the cleaning process is
a great deal easier. However, if the fossil has a softer
structure, then chemical substances need to be used. One
of the most commonly used methods is to clean away the
matrix with acid. This enables all the fossil's details
to be brought out. In some situations—particularly
when the fossil is very delicate and possesses the same
structure as the rock surrounding it—X-rays and computer-scanning
devices are used to determine the fossil's structure before
it is extracted from its location.
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Fossil Cleaning by Acid
One
method for cleaning fossils is to use acid. It is an efficient
method to clean the limestone rock surrounding a fossil
without harming it.
1. The rock surrounding
the fossil is submerged into the proper acid until a small
portion of the fossil appears.
2. The emerging section
of the fossil is washed and covered with a material resistant
to acid.
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3. Fossil is submerged
into acid once again, and these operations are repeated
a few more times.
4. The protective
material should be applied to the exposed portion of the
fossil, so as to protect it from any harm.
5. Finally the fossil
is entirely released from its surrounding rock. Fossil
is thoroughly washed to clean it of both the acid and
its protective material.
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INTRODUCTION
 Some
150 years ago, the British naturalist Charles Darwin
proposed a theory based on various observations
made during his travels, but which could not be
supported by any subsequent scientific findings.
In essence, his theory of evolution consisted of
various scenarios, ... MoreWHAT IS A FOSSIL?
 In
the broadest definition, a fossil is the remains
of a living thing that lived long ago and that has
survived down to the present day by being preserved
under natural conditions. The fossils that come
down to us are parts of an organism, or remains
left behind when the living thing concerned was
still alive ... More |
Fossil Specimens Discovered in The USA