Document Type

Article

Publication Date

8-1986

Abstract

Detailed demagnetization experiments isolated a characteristic remanent magnetization in ten stable sites from the upper Cretaceous Winthrop and Midnight Peak Formation in the Methow-Pasayten belt of north-central Washington. This remanence agrees best between opposite limbs of a fold (the Goat Peak syncline) when corrected for 46% of tilt. This is consistent with magnetization acquired during deformation. Synfolding magnetization may have been facilitated by a thermo-chemical event associated with synkinematic intrusions along the axis of folding. The mean direction (D=12.0°, I=61.1°, Alpha-95=4.8°) is highly discordant with respect to the expected direction for north-central Washington. This discordance points to about 1,400 km of poleward transport and 48 of clockwise rotation between 93 and 45-48 Ma.

Publication Title

Geophysical Research Letters

Volume

13

Issue

8

First Page

733

Last Page

736

Required Publisher's Statement

Published by American Geophysical Union

Subjects - Topical (LCSH)

Geology, Stratigraphic--Cretaceous; Paleomagnetism--Washington (State)--Methow Valley; Synclines--Washington (State)--Methow Valley

Geographic Coverage

Methow Valley (Wash.)

Genre/Form

articles

Type

Text

Language

English

Format

application/pdf

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