Magnetostratigraphic constraints on the late Ediacaran paleomagnetic enigma.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41042859.
- Also identified by DOI 10.1126/sciadv.ady3258 and PMC identifier 12494014.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Paleogeography of the Ediacaran Period has remained poorly understood because of paleomagnetic studies commonly yielding perplexing or conflicting data. Here, we report new magnetostratigraphic data from the Ediacaran Ouarzazate Group in the Anti-Atlas Mountains of Morocco, which have primary magnetizations supported by a positive conglomerate test and stratigraphically consistent directions within volcanic units across multiple localities. Comprehensive magnetostratigraphic sampling shows highly variable directions, consistent with a rapidly changing geomagnetic field along a longitudinally preferred band. High-precision geochronology constrains the geomagnetic variability to ~568 to 562 million years and suggests rates that are likely too rapid for true polar wander or plate tectonic interpretations. Comparison of igneous- and sedimentary-derived data, using a new statistical approach combining Bingham and Fisher distributions, indicates a high-inclination paleomagnetic direction that is compatible with independent evidence for regional glaciation. Our analysis produces a late Ediacaran paleogeographic reconstruction that is consistent with paleomagnetic and geologic constraints.