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The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 42 (1958)

Issue: 1. (January)

First Page: 216

Last Page: 216

Title: Llano Seco and Perkins Lake Gas Fields, Butte and Tehama Counties, California: ABSTRACT

Author(s): Tod P. Harding

Article Type: Meeting abstract


The Perkins Lake and Llano Seco gas fields are in the north point of the Sacramento Valley 12 and 16 miles, respectively, southwest of the city of Chico.

The Llano Seco field was discovered in November, 1954. Production is from the Upper Cretaceous Estes and Sannar sands at a depth of approximately 3,300 feet. Structurally, the field is on a broad, symmetrical north-trending anticline.

The larger Perkins Lake field, discovered in September, 1955, produces from the lower Eocene "Perkins Lake" sand at depths ranging from 3,365 to 3,505 feet. The structure is an elongate, northeast-trending anticline.

Stratigraphically, the two fields are quite dissimilar. The Llano Seco field has an almost normal sequence of lower Eocene and Upper Cretaceous beds, whereas the Perkins Lake field, being in an Eocene erosional gorge, has a lower Eocene section which is greatly thickened at the expense of the Upper Cretaceous section. The pronounced unconformity at the base of the Eocene is found 1,300-1,800 feet lower at Perkins Lake than at Llano Seco, whereas within the Cretaceous the two fields are nearly flat structurally.

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Copyright 1997 American Association of Petroleum Geologists