Weighing 3034 kilograms (6690 lbs) and measuring two metres across with a maximum height of 88 centimetres, this impressive specimen was discovered in March on the shore of the Athabasca River south of Fox Creek. This spectacular find provides a glimpse of Alberta's landscape around 60 to 65 million years ago, shortly after the distinction of the dinosaurs.
While the wild rose may be Alberta's best-known emblem, many may not realize that in 1977, petrified wood was designated the official stone of Alberta. Petrified wood is a common part of any young Albertan's rock collection and small pieces can be found throughout the province. However, large, intact and well-preserved tree stumps are rare.
This is the largest fossil specimen ever recovered from a remote location in Alberta.
The tree is a conifer. The exact species has yet to be determined.
Petrified wood is considered a fossil. Fossils are the remnants of living organisms in the past that have been preserved. Petrified wood is comprised of finely crystalline quartz and other minor accessory minerals that have entirely replaced the original wood. The word petrify originates from the Greek word petros, meaning "stone" or "rock".
This tree has been preserved by two different processes. The majority of the stump has been petrified by the process of permineralization. This involves the replacement of organic structure by minerals, in this case quartz. Other small parts of the stump have been preserved by the process of coalification, in which organic matter is transformed into coal due to heat and pressure.
The specimen is likely about 60 to 65 million years old. It was living soon after the extinction of the dinosaurs.
We can estimate the age of the petrified tree stump based on the age of the rock in which it was found. This rock is part of the Paskapoo Formation, a sandstone which is early Paleocene in age. The Paleocene is unit of geological time spanning 56 to 65 million years. The age of a rock unit is determined by analyzing its component minerals and included fossils, especially microfossils such as pollen.
Elements such as manganese, iron and copper in the water/mud during the petrification process give pertified wood a variety of colour ranges. Following is a list of contaminating elements and related colour hues: Carbon - black Cobalt – green/blue Copper – green/blue Iron oxides – red, brown and yellow Manganese – pink/orange Manganese oxides – blackish yellow
Although petrified wood is common throughout Alberta, large and well-preserved specimens are rare. This is the largest petrified tree stump ever collected in the province. This is also the largest palaeontological specimen collected to date from a remote location in Alberta.
This specimen shows a remarkable preservation of small-scale structure. This may assist in determining the species of tree. Counting its rings should provide an estimate of the tree's age when it died.
Preliminary cleaning has been completed. During this process, the specimen was allowed to dry slowly to prevent cracking. A specially-constructed crate was built with a cushion of sand to provide safe support.
Curatorial staff will undertake research to determine the species of tree and better constrain its geologic age. The results of this research will inform the display at the planned downtown Royal Alberta Museum as well as the Museum's public and education programming.
Thanks to the Royal Alberta Museum and the Director of Visitor Experience at the Museum for the the above information.
To log this Earthcache, e-mail answers to the following questions to the cache owner.
1. How long ago was the stump of this tree alive.
2. The majority of this speciman was fossilized by what known process?.
3. This specimen shows a remarkable preservation of small-scale structure, by looking closely can tree rings be seen?
4. In your opinion what element was most prevalent during petrification that gave the specimen its most prominent colour.
5. On the plaque at the site who is acknowledged.
( Unfortunately The plaque has gone missing therefore this question no longer applies )
6. Optional - feel free to post a picture of you or your GPS at the site. Please do not include a picture of the interpretive plaque.