The Death Valley turtlebacks reinterpreted as Miocene­ Pliocene folds of a major detachment surface

The Journal of Geology
By: , and 

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Abstract

Determining the origin of extension parallel folds in metamorphic core complexes is fundamental to understanding the development of detachment faults. An excellent example of such a feature occurs in the Death Valley region of California where a major, undulatory, detachment fault is exposed along the well-known turtleback (antiformal) surfaces of the Black Mountains. In the hanging wall of this detachment fault are deformed strata of the Copper Canyon Formation. New age constraints indicate that the Copper Canyon Formation was deposited from ~6 to 3 Ma. The formation was folded during deposition into a SE-plunging syncline with an axial surface coplanar with that of a synform in the underlying detachment. This relation suggests the turtlebacks are a folded detachment surface formed during large-scale extension in an overall constrictional strain field. The present, more planar, Black Mountains frontal fault system may be the result of out-stepping of a normal fault system away from an older detachment fault that was deactivated by folding.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title The Death Valley turtlebacks reinterpreted as Miocene­ Pliocene folds of a major detachment surface
Series title The Journal of Geology
DOI 10.1086/629715
Volume 102
Issue 6
Year Published 1994
Language English
Publisher The University of Chicago Press
Description 10 p.
First page 718
Last page 727