Field trip road log—geology and tectonics of the Gualala block

Compiled by: Thomas B. Anderson and Richard G. Stanley



The Pacific Section, S.E.P.M. 1998 Fall Field Trip will traverse rocks of the Gualala block of northern California. Seven stops (Figure 1) will be made in one and a half days and will examine a variety of geologic features and rock types in this significant area. The field trip is an outgrowth of a symposium held at the 1998 Annual Meeting of the Pacific Section, S.E.P.M. in Ventura, California, where eleven papers were presented. The field trip stops will focus on the effects of the 1906 California earthquake, the nature and significance of the spilite of Black Point, the basement of the region, comparison of different turbidite sequences in the Paleocene/Eocene German Rancho Formation, young tectonics in the northern part of the block, the paleontology and structural significance of the Upper Cretaceous Anchor Bay Member of the Gualala Formation of Wentworth (1966), and the geology of the Miocene Point Arena Formation at Arena Cove. At several stops, the origin of the Gualala block which has traveled progressively northwest as a result of movement along the San Andreas fault system will be discussed.

Additional publication details

Publication type Book chapter
Publication Subtype Book Chapter
Title Field trip road log—geology and tectonics of the Gualala block
Year Published 1998
Language English
Publisher Society for Sedimentary Geology
Contributing office(s) Geology, Minerals, Energy, and Geophysics Science Center
Description 10 p.
Larger Work Type Book
Larger Work Title Geology and tectonics of the Gualala block, northern California, SEPM Book 84
First page 213
Last page 222