Navajo Sandstone concretions record extended magnetic chronology.

ABSTRACT: This study investigates iron oxide concretions from the Jurassic Navajo Sandstone in Utah as potential recorders of long-term magnetic field variations. Using a combination of alternating field and thermal demagnetization, physical abrasion, chemical analysis, and magnetic modeling, we reveal multiple magnetic components with contrasting directions within individual concretions. Finite Element Magnetic Modelling demonstrates the sensitivity of magnetic signatures to small changes in layer thickness. X-Ray Fluorescence spectrometry confirms high iron concentrations in concretion crusts. Our results support a two-stage formation model involving initial iron hydroxide precipitation followed by progressive transformation to hematite. This extended formation process suggests these concretions m

SUBMITTER: Smrcinova L 

PROVIDER: S-EPMC11794945 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature