Petrified and fossilised araucaria tree trunk with lineage of over 220 million years. The wonderful fossilised tree trunk has undergone several process’s to eventually be exhibited here, it's story began millions of years ago. It is generally accepted that natural disasters felled these ancient trees, carried them in flash floods or landslides to be laid down in sodden ground or shallow water, which were mineral rich environments.
The tissue of the wood may have started to decay. Later through the actions of volcanism, the deposited forrests were covered with deep ash layers creating an anoxic atmosphere in water or mud. Later as metres of ash covered the trees, the depositing layers of ash and earth persisted the anaerobic environment. Soluble minerals held in water were forced through the tissues of the wood at molecular levels, cell by cell the vascular system of the tree was transformed, as mineral growth turned the tree into quartz rich semi precious stone, petrification occurred and fossilised the tree for all time.
In this extraordinary deposition quartz, in the form of Jaspers and calcites have solidified over millions of years creating a solid stone tree. Growth rings can be picked out in bands of varing colours. A very remarkable and rare verde colouration, which over millions of years, has created the fossilised outer bark. While jasper has been absorbed by the internal trunk tissues and have created the attractive darker red tones within the once living tissue of the tree.
Petrification takes place as the spore spaces in living tissues of the wood are replaced by minerals, through a process of permineralisation mineral laden water seeping through the tissue of the once living wood and creates an internal cast cell by cell. In this way the wood is preserved at a microscopic level, minerals form on the cell walls and eventually fill each cell preserving the internal structure of the tree and replacing the whole body by the process mineralisation.
The genus type Araucaria is of the Araucariaceae family, related to the modern day more commonly known 'Monkey Puzzle' tree lineage. Araucaria flora are often referred to as the ‘living fossil’. The trunk has been unearthed and cleaned gently. The minimal cleaning resulting in a splendid and unique fossil specimen of the finest quality, an exhibit which would grace any museum or fossil collection.