Polished Acaciella australica Stromatolites

Geological Time: Neoproterozoic (800 Million Years Old)

Size (25.4 mm =1 inch): 135 mm by 115 mm (maximum)

Fossil Site: Bitter Springs Formation, Alice Springs, Northern Territories, Australia

Fossil Code: AS13037

Price: Sold

Description: This is a branching stromatolite known as Acaciellla australica from the Bitter Springs Formation of Australia. The assemblage found there is ideal for the study of both the microbial and environmental influences on stromatolite morphology. The basal hemispheroidal section shows the presence of abundant sediment while the columal sections are formed primarily of the laminae seen here. The shift to a columnal form is thought to be an outgrowth of a decreased sediment supply leading to a more stable environment in which the growth of the microbial mats served to define the stromatolitic shape. This is an excellent cross section which has been polished on one side to show off the structures.