Increased intensity of activity in producing areas, notably in the Mesozoic oil and Paleozoic oil and gas basins of northern Europe. Although gas production from the Tertiary basins of southern Europe continued to increase, this area was notable for Mesozoic wildcat exploration and successes during 1981. The trend of decreasing oil production in southern Europe may be halted if the discovery rate for the Mesozoic play is maintained or increased. The discoveries of gas in the Mesozoic basins of the Atlantic borderlands include some "giants." Development of these discoveries and the associated gas discoveries of the North Sea is likely to cause a change in the trend of decreasing gas production from northern Europe.--Modified journal abstract.