Britannica Sources used in this answer

How large were stromatolites in the Steep Rock Lake belt of Ontario?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

A detailed geologic time scale chart displaying Earth's history from the Hadean Eon over 4.5 billion years ago to the present, organized by eons, eras, periods, epochs, and ages with color-coded columns and corresponding dates in millions of years. — Precambrian The stratigraphic chart of geologic time.

In the 2.7-billion-year-old Steep Rock Lake belt located in Ontario, Canada, stromatolites reach up to 3 metres (9 feet) in both height and diameter.1