Exploratory drilling in the shallow-sand territory of western Pennsylvania (Upper Devonian or higher) during 1948 led to the discovery of 5 new gas pools and one oil pool. None of these, however, seems to be significant in size. The total number of shallow wells drilled, exclusive of those drilled in connection with underground gas storage and secondary-recovery oil operations, was 10 per cent less than in 1947. In the Pennsylvania part of the Bradford oil field, which continued to be the most active area, 2,070 new wells were completed, as compared with 1,840 in 1947. About half of these were water-intake wells. The Bradford field accounted for 80 per cent of the total oil production in Pennsylvania during 1948. The average daily oil production in the state in 1948 was 3 ,206 barrels, as compared with 35,242 barrels in 1947.

Thirty new wells were completed to the deeper formations (Onondaga or deeper) as compared with 28 in 1947. Of these, two were drilled for gas storage purposes. Of the remainder, 9 were gas wells and 19 were dry holes. Two of the wells, located in Erie County, were completed as dry holes in the Corry Medina sand gas pool. They definitely established that this pool, discovered in 1948, is of only small extent. The greatest activity centered in the East Fork Oriskany sand gas pool of north-central Pennsylvania where 8 wells were completed, whose initial open-flow capacities ranged from 2 to 10 million cubic feet of gas per day. The limits of this pool have not been defined and this development, no doubt, will greatly stimulate further prospecting of the Oriskany underneath the Allegheny lateau in central Pennsylvania.

The Cambro-Ordovician possibilities of the state received considerable attention during 1948. Several major companies conducted geological and geophysical surveys and one test on the Schellsburg dome east of the Allegheny Front in south-central Pennsylvania was underway at the end of the year.