Formation of the Timiskaming Graben corresponded with collapse of the regional crust along the Quinze Dam and Cross Lake faults possibly as early as 2.4 billion years ago. It was then reactivated during periods of crustal extension related to the breakups of supercontinents Rodinia and Pangaea and during compression related to the various orogenies that formed the Appalachian Mountains. The Timiskaming Graben is now partially filled by Lake Timiskaming, a long successor to the much larger glacial Lake Barlow which drained at the end of the last glacial period about 8,000 years ago.