Publikationen

Accumulation of ferromanganese crusts derived from carrier-free <sup>10</sup>Be/<sup>9</sup>Be

Autor(en)
Johannes Lachner, Marco Ploner, Peter Steier, Aya Sakaguchi, Akira Usui
Abstrakt

The occurrence of 10Be in natural archives is commonly used to date their formation and growth on time scales of million years. Accelerator Mass Spectrometry (AMS) can perform a direct measurement of the 10Be/9Be ratio. The carrier-free method, in which no 9Be carrier is added to the original sample, is especially suitable for 10Be/9Be ratio determination in the marine environment. By normalizing the 10Be content to 9Be, temporal variations of Be uptake processes into the archive are eliminated. Here, we present a simple method for the chemical extraction of beryllium from ferromanganese (FeMn) crusts or nodules, the measurement procedure, and the first carrier-free 10Be/9Be measurements at the 3 MV AMS facility VERA. Several tests of chemical methods are discussed including different options to short-cut and accelerate the procedure for special cases. Results from FeMn crust 237KD from cruise VA13/2 in the Pacific ocean show the known 10Be/9Be distribution with depth that is commonly related to a changing growth rate of the archive. In this context we discuss the potential influence of diffusion and adsorption processes on the age models of FeMn crusts that are based on radioactive nuclides such as 10Be and 230Th. Including an open-system behavior for these isotopes in the description of their profiles allows interpreting the accumulation of crusts with a constant growth rate over millions of years and does not require the assumption of abrupt growth changes.

Organisation(en)
Isotopenphysik
Externe Organisation(en)
National University Corporation Tsukuba University of Technology, Kochi University, Universität Wien
Journal
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Band
467
Seiten
146-151
Anzahl der Seiten
6
ISSN
0168-583X
DOI
https://doi.org/10.1016/j.nimb.2019.11.047
Publikationsdatum
03-2020
Peer-reviewed
Ja
ÖFOS 2012
103014 Kernphysik
Schlagwörter
ASJC Scopus Sachgebiete
Nuclear and High Energy Physics, Instrumentation
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/accumulation-of-ferromanganese-crusts-derived-from-carrierfree-10be9be(8464de23-d04d-4cd3-b593-43f7efd329d0).html