This specimen is from the Gunflint Formation, a Paleoproterozoic chemical-clastic sedimentary assemblage outcropping to the immediate northwest of Lake Superior that became famous, in 1954, for containing the oldest fossil assemblage known at that time.
Older microfossils have since been discovered, but the Gunflint prokaryotes remain one of the most diverse Precambrian fossil communities.
Scientists think that the Earth's rotational rate during this era resulted in 20-hour days ~1.8 billion years ago, implying a total of about 450 days per year!
The wavy laminae seen here of the chertized stromatolites (chert is cryptocrystallized quartz) represents a facet of the early history of life on Earth. Location: Gunflint Formation, Ontario, Canada (outside of the nature preserve), circa 1963.
Size: 35mm W X 39 mm H X 12mm D.
Ships with tag, tag stand, Certificate of Authenticity, information about the Gunflint Stromatolite formation. Acrylic base and photo cube not included.
This is a superb specimen with pyrite mineralization clearly seen with other contrasting dark features, in this rare stromatolite from the Gunflint Range, Canada.