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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 34 (1950)

Issue: 12. (December)

First Page: 2383

Last Page: 2384

Title: Santa Maria Region: ABSTRACT

Author(s): B. C. Lupton

Article Type: Meeting abstract

Abstract:

The Santa Maria province is a roughly triangular area in the California coastal belt which is bounded on the west by the Pacific Ocean, on the south by the Santa Ynez Mountains, and on the north and northeast by the Santa Lucia Range. The province consists of several more or less isolated structural basins with similar sedimentary histories and related types of objective zones and traps.

Many types of rocks underlie the zones of present and prospective production. The term, basement, as used in this paper, refers to rocks older than Eocene that consist of Jurassic metamorphics and basic intrusives and Cretaceous and Jurassic sediments that have undergone various degrees of alteration.

The Santa Maria province has an area of 2,126 square miles, of which 1,824 square miles are underlain by objective sediments. The volume of unaltered sediments is estimated at 1,112 cubic miles and the maximum depth to basement rocks is approximately 16,000 feet.

About 400 exploratory wells have been drilled in the province, resulting in the discovery of 14 productive areas with a cumulative production to December 31, 1949, of slightly more than 300 million barrels of oil.

Production is largely from Miocene sands, shales, and cherts. Significant amounts of oil have been produced from lower Pliocene sands and in one area from fractured sandstones of Jurassic age. This Jurassic production is considered to have migrated from overlapping Miocene beds.

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Prospective sediments range in age from Eocene to Pliocene. They are marine, with the exception of minor amounts of lower Miocene non-marine beds near basement highs and a veneer of upper Pliocene and Pleistocene continental beds in the central portion of the province.

Commercial oil production comes from anticlinal closures and stratigraphic and fault traps.

It is probable that substantial undiscovered reserves of heavy crude exist in this province, and that lighter oils may be found in parts of the stratigraphic section or in areas not before subjected to intensive search. Stratigraphic and structural studies may well be expected to yield important discoveries.

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Copyright 1997 American Association of Petroleum Geologists