Rock varnish and the manganese oxide connection.
DiGregorio
Barry E
BE
Cardiff Centre for Astrobiology, Wales, UK.
D001272:Atmosphere; D001419:Bacteria / Q000378:metabolism; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D055593:Geological Phenomena; D005844:Geology; D017895:Manganese Compounds / Q000737:chemistry* / Q000378:metabolism*; D010087:Oxides / Q000737:chemistry* / Q000378:metabolism*
D017895:Manganese Compounds; D010087:Oxides; C027424:manganese oxide