art and soul gallery
      HomeAbout UsCafeArtistsContact UsExhibitions
      
Product Categories
Paintings/Drawings
Sculptures
Photography
Great Gifts
Kiln-Fired Glass
Leadlight Lamps
Ceramics
Hand-Painted Tableware
Jewellery
Fibre Art
Upcycled Art
Exhibitions

art and soul gallery

Exhibitions > underworld by John Jackson 210511



Evolving the reef

Price:





        
Evolving the reef

The fossil record shows that “reef building” organisms have been diverse. The oldest is the stromatolite-building cyanobacteria (blue-green algae) and is shown in this painting as tan with tinges of yellow and green. They exhibit porous and closely packed calcitic tubes that are here painted in a dark brown-red.  Stromatolites are one of the oldest life forms on earth. They first appeared around three and a half billion years ago and their relatives are still alive today. They can be seen in Shark Bay in Western Australia.

 

The area behind the reef is often referred to as “back reef”. The spherical pink “balls” in this painting represent “Ooids” in the “back reef”. Ooids show concentric, carbonate lamellae being accreted around a nucleus of carbonate or quartz. They form in waters that are constantly being agitated by tidal, wave and/or storm activity.

 

Beneath the stromatolite reef, are the yellow, orange and brown folded rocks of the basement. Here these rocks have been faulted up to form a foundation for the reef to grow on.

 

In front of the folded basement rocks are the orange to yellow, asymmetrical, “Tepeed Oncolites”. Oncolites are made by cyanobacteria that need light to grow. These oncolites were formed in the shallow, warm water of the “back reef.” The bacteria secrets a mucus of calcium carbonate around a sand grain. Then they move to the outside of their deposit to stay in the light thus forming a rough, spherical ball as they move backwards and forwards with tidal currents. At some point in time these oncolites were transported by a storm to the “fore reef” (in front of the reef). Here the water is deeper and darker. There is little tidal or storm influence. To survive the bacteria grow “tepees” toward the light.




Shopping cart software
and credit card processing provided by ezimerchant