Francis Harold Brown (October 24, 1943 – September 30, 2017) was an American geologist and geochemist who mapped the sedimentary sequence and geology of most of the Turkana Basin in Kenya, east Africa. Brown introduced single-crystal argon-argon and potassium-argon dating into the Turkana Basin, resolving disputes over the age of Kenyanthropus platyops and other fossils.[1][2]