[1] Mineral production was limited to clay and volcanic rock; potential exists, however, for the development of the country's petroleum industry.
[1] Indications of the existence of hydrocarbons in São Tomé and Príncipe were first noted in 1974, but attempts by the Portuguese Colonial Administration to sign a concession agreement with Ball & Collins North Sea consortium (a predecessor of Premier Oil of the United Kingdom) were abandoned following the country's declaration of independence in 1975.
The JDZ was divided into nine blocks, and a licensing round was opened for bids in 2004, which resulted in the award of Block 1 to a consortium made up of Chevron Corporation of the United States (51%), Esso Exploration and Production Nigeria-Sao Tome (One) Ltd. (40%), and Dangote Energy Equity Resources Ltd. (a joint-venture of the Dangote Group of Nigeria and Energy Equity Resources AS of Norway) (9%).
The consortium signed a production-sharing agreement with the JDADA in 2005 and, in January 2006, began drilling activities within the block.
[1] Since 2006, there has been no word on any of the reexamination of ERHC's preferential rights and the countries of Sao Tome and Nigeria are moving forward with the exploration of the JDZ for oil.