Description: Publication date: Available online 15 December 2014 Source: Quaternary Geochronology Author(s): O. Trandafir , A. Timar-Gabor , C. Schmidt , D. Veres , M. Anghelinu , U. Hambach , S. Simon Previous works focused on optically stimulated luminescence dating of quartz extracted from Romanian and Serbian loess reported significant discrepancies between ages obtained on fine (4-11 μm) and coarse (63-90 μm) quartz. The present study is directed at expanding these investigations. The SAR-OSL and double SAR-OSL protocols are applied on quartz of different grain sizes belonging to 9 samples extracted from a newly identified archaeological site at Bistricioara-Lutărie III on the Bistrița Valley (NE Romania). Radiocarbon ages are also obtained for the 3 uppermost cultural layers hosted in the loess-like deposit. Discrepant ages are obtained between fine (4-11 μm) and coarse (63-90 and 90-200 μm, respectively) quartz for equivalent doses higher than ∼80-100 Gy. However, a very good agreement is achieved for the youngest sample, with an age of ∼8 ka (with a D e of 38 Gy for fine and 35 Gy for coarse grains, respectively). The comparison with independent control provided by radiocarbon dating suggests better agreement of ages calculated for coarse quartz. Our results are once again proof that concerns should be raised regarding the reliability of the equivalent doses obtained on quartz samples for which the laboratory dose response cannot be fitted by a single saturating exponential function. Further systematic investigations are required regarding the very different saturation characteristics of fine and coarse grained quartz.