The original symposium on “Possible Future Oil Provinces of the United States,” published in 1941, contained no discussion of the Tertiary formations of the western Gulf coast comprising parts of the states of Louisiana and Texas. This part of the Gulf coastal area was considered to be an oil-producing province; however, there were unexplored zones then, and are now, within the area of the present oil province.

Since the Gulf Coast Tertiary of Louisiana and Texas occupies the major position in production and reserves of the entire United States, its inclusion with possible future oil provinces may seem strange. Present production and known reserves are situated, however, almost entirely at depths less than 10,000 feet. This survey includes the sedimentary column to a depth of 20,000 feet.

Several fields are producing oil below 10,000 feet in formations where the actual top of the producing formation is much less than 10,000 feet, but the estimates of volumes of sediments for this province are for areas where the top of each formation considered to be in the future oil province is recorded at depths of 10,000 feet or more.

Underlying the area presently productive in Texas are two zones: one, 5,000 feet thick on the average, between 10,000 feet and 15,000 feet in depth, which must be classed as possible; and a second, between 15,000 feet and 20,000 feet in depth, which is so speculative it can not now be considered a possible oil province. It is so remote, both laterally and