Stromatolite fossil Без бренда

This stromatolite fossil is from the Rocky Mountain Belt Supergroup, extreme northwestern Montana, USA, 

 Age is proterozoic, about 1.2 billion years old. Stromatolites are the only plant fossils found in this area, They are formed by algae mats interspersed with calcium carbonate layers. and can attain sizes measured in meters. They were one of earth's earliest life forms.

  The stromatolite offered here shows very fine detail of the alternating algae/CaCo3 layers thanks to being exposed to the elements. The two alternating layers reveal a difference in the rate of chemical weathering as well as the actual structure of the organism.

  The slightly domed habit is typical of stromatolites.

7" x 4" x 3" in size, about 1.5 lbs.

Excellent.