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Geological
Time: Proterozoic (2.2 to 2.4 Billion Years Old)
Size (25.4mm=1
inch): 100 mm by 70 mm, up to 40 mm thick
Fossil Site:
Ord Ranges, Port Headland, Western Australia
Code: ST040
Price: sold
| Description: A polished section of what is termed
locally “Tiger Iron”. Known as Jaspelite, it is a banded
structure of Tiger Eye, Red Jasper, and Hematite. Stromatolites are
remnants of the most ancient of colonial organisms. Stromatolites
are fossils that are the result of the work of simple blue-green “algae”
or Cyanophytes, which lived in chains or mats covered in a jellylike
substance. By taking in carbon dioxide as a food source, the precipitate
limy deposits on the jelly that builds up in layers. Thus these organisms
build up stony supports for their colonies. These mound like structures
can be anywhere from several centimeters to several meters in height.
The production of oxygen is thought to have led to the “rusting
of the seas” which brought about deposition of extensive iron
deposits such as the Mesabi Range. Hematite is an iron mineral, and
is one of the components of this banded structure (dark bands). Stromatolites
have persisted to the modern day in such places as Shark Bay, Australia
where they continue their billions of years old lifestyle. This one
is quite natural in appearance on all but the surface which has been
given a high polish to show off the myriad of colors. While this piece
would make a fine present for any natural history buff, anyone who
appreciates art would also be glad to get thus wonderful specimen
as a gift. |
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