First occurrence of Paleoproterozoic oceanic plateau in the Guiana Shield: The gold-bearing El Callao Formation, Venezuela

► First documented occurrence of Fe-rich tholeiitic basalts in Guiana Shield of South America. ► First documented occurrence of primitive mantle basalt in an oceanic plateau in South America. ► Basalt in the Guasipati-El Callao Greenstone Belt is Fe-rich tholeiite. ► Basalt in the Guasipati-El Callao Greenstone Beltis formed in an oceanic plateau setting, from a primitive mantle plume. ► Volcanic rocks in the Guasipati-El Callao Greenstone Belt have an elevated potential for hosting gold mineralization.