Hamelin Pool is the location of the best example in the world of living marine stromatolites. The water here has twice the salinity of sea water because of a bar across the Bay's entrance and rapid evaporation from the shallow water. Most living animals, which feed on the bacteria and algae, cannot tolerate such saline conditions. As a result stromatolites grow here undisturbed, at a maximum rate of 0.3mm a year!
For at least three-quarters of the earth's history stromatolites were the main reef building organisms, constructing large masses of calcium carbonate.
However their most important role in the history of the earth has been that of contributing oxygen to the earth's atmosphere. The organisms which construct stromatolites are photosynthetic. They absorb carbon dioxide, water and sunlight, and in doing this, liberate oxygen into the atmosphere.
Stromatolite fossils are evidence of the earliest life on the earth. Western Australia perhaps has the best stromatolite fossils, giving a record through the eons of time. Fossils of the earliest known stromatolites, about 3.5 billion years old, are to be found near Marble Bar in the Pilbara.
Pied Cormorant.
Cumulus sky - arid landscape at Hamelin Pool.
This photo is for Jo who says of me ‘why aren’t you in any of the blog pics!’
No comments:
Post a Comment