Optimization of Itrax Core Scanner Protocols for the Micro X-Ray Fluorescence Analysis of Finely Laminated Sediment: A Case Study of Lacustrine Varved Sediment from the High Arctic.

• Main Authors: Cuven, Stéphanie, Francus, Pierre, Crémer, Jean-François, Bérubé, Francis
• Other Authors: Croudace, Ian W., Rothwell, R. Guy
• Format: Book Part
• Language: unknown
• Published: Springer 2015
• Subjects: laminated sediment; varves; micro X-ray fluorescence; paleoenvironment; climate reconstructions; Arctic
• Online Access: https://espace.inrs.ca/id/eprint/3824/; https://doi.org/10.1007/978-94-017-9849-5_10

Use of the highest resolution (0.1 mm) step-size of the Itrax core scanner on fine-scale structured sediment requires careful prior evaluation of the data. The first step for optimization is to select the best Itrax acquisition settings to obtain a robust geochemical record. μ-XRF results reproducibility can then be evaluated according to the abundance and the detectability of elements. Data are considered as ‘good quality’ when elements are highly or moderately detectable and highly abundant in the sediment. They are of ‘medium quality’ if elements are poorly detectable but highly abundant in the sediment. Data are described as ‘low quality’ when elements are highly and moderately detectable and moderately or weakly abundant. Further assessment of analytical errors shows that topographical anomalies on the core surface may decrease validity of μ-XRF results without consequences on the quality of the micro-radiography. Optimized protocols for µ-XRF acquisition are then applied to an Arctic lacustrine varved sediment sequence. This case study highlights the high potential of micro X-ray fluorescence for paleohydrological and -climatological interpretations at very high temporal resolution (i.e. annual and inter-annual scales).