Searching for stromatolites: The 3.4Â Ga Strelley Pool Formation (Pilbara region, Western Australia) as a Mars analogue

► Stromatolites are easily identified indicators of potential biological activity in outcrop. ► The oldest stromatolites on Earth (∼3.5 Ga) are coeval with the martian Noachian. ► Stromatolites may be the most easily identified evidence for Noachian life. ► Finding them will careful site targeting, long range traverses, good terratin-crossing abilities and comprehensive instrumentation. ► Proving their biogenicity will almost certainly need sample return.