Fossils occur commonly around the world although just a small
proportion of life makes it into the fossil record. Most living
organisms simply decay without trace after death as natural
processes recycle their soft tissues and even hard parts such as
bone and shell. Thus, the abundance of fossils in the geological
record reflects the frequency of favourable conditions where
preservation is possible, the immense number of organisms that have
lived, and the vast length of time over which the rocks have
accumulated.
The term 'fossilization' refers to a variety of often complex
processes that enable the preservation of organic remains within
the geological record. It frequently includes the following
conditions:
- Rapid and permanent burial/entombment - protecting the specimen
from environmental or biological disturbance
- Oxygen deprivation - limiting the extent of decay and also
biological activity/scavenging
- Continued sediment accumulation as opposed to an eroding
surface - ensuring the organism remains buried in the
long-term
- The absence of excessive heating or compression which might
otherwise destroy it.
Fossil evidence is typically preserved within sediments
deposited beneath water, partly because the conditions outlined
above occur more frequently in these environments, and also because
the majority of the Earth's surface is covered by water (70%+).
Even fossils derived from land, including dinosaur bones and
organisms preserved within amber (fossilized tree resin) were
ultimately preserved in sediments deposited beneath water i.e. in
wetlands, lakes, rivers, estuaries or swept out to sea.
Fossilization can also occur on land, albeit to a far lesser
extent, and includes (for example) specimens that have undergone
mummification in the sterile atmosphere of a cave or desert.
However in reality these examples are only a delay to decomposition
rather than a lasting mode of fossilization and specimens require
permanent storage in a climate controlled environment in order to
limit its affects.
Coal is typically formed from the fossilized remains of dead plants
that lived millions of years ago. The fossilized tree stumps at
this location were extracted from a mining operation some 8km south
of here. They were removed from a coal seam about 2.2m thick. The
stumps here are from a cypress tree that grew 68-70 million years
ago. The large stump was from a tree that was 200 or more years
old.
The base and root system indicate that they grew in a swampy
location. The age of the tree and its growing conditions are told
by the rings that are evident in the fractured stump.
In order to log this earth cache, please email (do not post) the
answers to the following questions:
- What was the name of the mining company that unearthed these
fossils?
- How far was the seam buried where these fossils were
found?
- (This part is optional as per EC guidelines) please post a
photo of yourself or your gps with a distinguishing land mark in
the background.
Ref: “Discovering Fossils Roy
Shepherd” discoveringfossils.co.uk
Informational signs at site