Early Pleistocene Deposits in the Netherlands Revisited
Abstract
The ages of Late Pliocene to Early Pleistocene deposits in the Netherlands and immediate surroundings are subject to continuous refinement. Here we report on an integrated stratigraphic effort to constrain the ages of fluvial and shallow marine sediments in the SE and NW Netherlands. The SE Netherlands are part of the Lower Rhine Embayment which was investigated with various methods since the early 20th century. Deposits of Early Pleistocene age and straddling the Pliocene-Pleistocene boundary in two clay pits, the Hoher Stall & Öbel pits, were investigated for their magnetostratigraphic record. Partly equivocal results were obtained due to the magnetic mineralogy with a foremost contribution of greigite. In an attempt to certify intervals of uncertain polarity the characteristic remanent magnetization was normalized by the anhysteretic remanent magnetization, an approach typically used to establish relative paleointensity records in case of constant sediment properties. Here, we seek to establish the efficiency of the acquisition of the natural remanent magnetization. Along the lines of Fuller et al. (1988) a depositional remanent magnetization (DRM) is not very efficient while chemical remanent magnetizations are deemed more efficient. Viscous remanent magnetizations could be more efficient than DRMs but are typically demagnetized at low AF levels or low temperatures enabling their discrimination. Indeed, large fluctuations in the slope of pseudo Arai plots were found. However, as we will show, their interpretation is not straightforward either.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMGP51B0643D
- Keywords:
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- 1165 Sedimentary geochronology;
- GEOCHRONOLOGY;
- 1520 Magnetostratigraphy;
- GEOMAGNETISM AND PALEOMAGNETISM;
- 4910 Astronomical forcing;
- PALEOCEANOGRAPHY