The largest area of oil possibilities in Brazil is the Amazon Valley. On Marajo Island, thick sediments have been proved recently by geophysics. The Maranhao Basin is being intensively investigated by the Conselho Nacional do Petroleo. In Sergipe, geophysical parties are working, and a test well was recently spudded. In Sao Paulo, six wells were drilled through Irati beds, finding oil but not in commercial quantity. In Bahia, development of the Candeias and Don Joao fields is in progress; the total production of Bahia in 1948 reached 143,405 barrels and total reserves were estimated at 17.8 million barrels. Much interest is being devoted to the production of oil from oil shales in the Paraiba Valley and the Gondwana series of southern Brazil. In the Paraiba Valley, the oi shales can yield 20-25 gallons of oil per ton. The more uniform Irati shales show enormous reserves, having an average yield of 23 gallons. Bituminous sandstones containing 8-14 per cent bitumen occur in Sao Paulo not far from the railroads. The sandstones were distilled for oil during the last war and now are mined for paving purposes.

Development of the oil-shale industry depends on economic factors determined by local conditions.