**5. Conclusions**

In the present study a sediment core sample of late Quaternary age was divided in six aliquots each of which was treated with reagents that do not alter foraminifera calcite geochemistry following different cleaning procedures and the efficiency of each method in specimen cleaning was assessed using SEM and X-ray tomography. The results of the visualization analyses were combined with shell weight measurements and allowed us to conclude that the method that has proven the most effective in removing fine detritus trapped within foraminiferal tests is a two-step treatment of the sedimentary material, named here HyPerCal treatment, initially with 2.5% hydrogen peroxide and subsequently with 5% Calgon solutions. The proposed protocol minimizes discrepancies in foraminifera shell weight measurements and greatly facilitates microfossil X-ray imaging analyses.

**Author Contributions:** Conceptualization, S.D.Z.; original draft preparation, G.K. and S.D.Z.; laboratory analyses, G.G., S.D.Z. and P.M.; SEM data acquisition, E.B. and V.L.; synchrotron data acquisition, V.S.C.K. and S.M., synchrotron data scientific computing and analysis, K.W. and S.D.Z.; writing—review and editing, G.K., S.D.Z. and A.A.; supervision, A.A. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** We would like to acknowledge Efterpi Koskeridou and Danae Thivaiou for access to the camera light stereomicroscope and photograph acquisition. This synchrotron X-ray scanning work was carried out with the support of Diamond Light Source, instrument I13-2 (part of proposal MG23868).

**Conflicts of Interest:** The authors declare no conflict of interest.
