shells, sharks and stromalites

Back to the coast and heading towards Shark Bay, another world heritage site due to its marine life and coastal features.

First stop was Hamelin pool, one of only two places on earth where living marine stromalites exist.

The existence of stromalites highlights one of the many gaps in my education, and I had absolutely no idea what there were. It transpires that they are considered 'living fossils' and consist of layered limestone rock built by single-celled cyanobacteria which trap and bind the sediment. 3.5 billion years ago atmospheric oxygen was scarce, but as stromalite colonies expanded they released more oxygen eventually raising the level to 20 % and enabling air-breathing life forms to evolve.

So we can thank these little puppies for our existence:

From trek phase 3

From trek phase 3

From trek phase 3

From trek phase 3

The pool is located near an old telegraph station and the buildings were made by mining limestone made from 6000 year old shells from the Cardiid cockle. Calcium carbonate leached from the shells then dried to form a binding agent producing the soft limestone called coquina ( which , if nothing else, is a fabulous Scrabble word). It is funky stuff.

From trek phase 3

From trek phase 3

From trek phase 3

The camp site at the telegraph station has a collection of old post office signs, just in case any of you were missing the post office feature.

From trek phase 3

Further up the coast is shell beach- no sand, just piles and piles of cockle shells.

From trek phase 3

From trek phase 3

Ness could not resist throwing herself into the ocean:

From trek phase 3

Possibly not her best idea to date.....they call it Shark Bay for a reason:

From trek phase 3