sentence: There are numerous examples of modern analogues of actively forming or recently formed stromatolitic structures such as those in Lake Joyce and Lake Fryxell , Antarctica ( Mackey et al ., 2015 ; Sumner et al ., 2015 ) , alkaline salt lakes ( Arp et al ., 1999 ) and marine environments ( Reid et al ., 2000 ; Visscher et al ., 2000 ; Burns et al ., 2004 ; Pag è s et al ., 2014 ) as well as 2000 ‐ year ‐ old structures in Lagoa Salgada , Brazil , ( Birgel et al ., 2015 ) .