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tokens: to resolving the Ba puzzle. To examine this possibility, we have selected a set of nine iron lines from the table in Gurtovenko Sheminova ( 2015 ) whose formation depth is far from the continuum forming layers in the range of log ( τ 5000 ) = −2.0 to −4.0. We show in Figure 12 the differential iron abundances of these lines (Table 4 ) covering the EWs range 60 to 160 mÅ in the spectra of HD 96116 and HD 222582 as a function average depth of line formation. All these abundances are measured using the stellar parameters listed in Table 1 whose values are based on the analysis of weak and moderate strength iron lines of EW 70 mÅ (Nissen 2015 ). It is evident from Figure 12 that HD 96116 with relatively high stellar activity has a systematically higher iron abundances for the strong lines formed in the upper layers of the photosphere (log ( τ 5000 ) −2.0) than the mean abundance of +0.01 dex derived for lines formed deep in the photosphere. Such a trend of iron abundance with depth of line formation strongly suggest a height-dependent microturbulence with velocity increasing toward the top of the photosphere and the transition to the chromosphere. From the very similar iron abundances for the strong Fe lines in HD 222582 suggest that the photospheric structure of the inactive star HD 222582 of age 7 Gyr is very similar to that of the Sun. Figure 12. Differential iron abundance derived from the adopted stellar parameters in Table 1 as a function of the average depth of line formation. Table 4 Iron Abundances for a Set of Nine Saturated Iron Lines along with the Average Depth of Formation in the Stellar Photosphere These results strongly suggest that the microturbulence increases steeply with height in the photospheres of active stars relative to dwarfs of age less than the Sun. As a result, the application of the microturbulence value derived from the weak and moderate strength iron lines to strong lines such as the Ba ii lines result in a serious overestimation of the Ba ii abundances in stars younger than the Sun. For the star HD 96116, an increase of microturbulence by about 0.3 km s −1 will drop [Ba/Fe] from the Ba ii 5853 Å line close to the abundance measured for the other heavy elements La−Sm. It is well understood from the analysis of the Sun that the chromospherically active phase of the Sun is associated with active upper photospheric layers (Schrijver et al. 1989 ) and thus chromospherically active young stars in the field, OCs, and associations have active photospheric layers from where the Ba ii lines emerge. As a result all those active stars, as found here and in previous studies, have Ba ii abundances overestimated by the standard LTE abundance analyses where the microturbulence is assumed depth-independent and derived from the weak/moderate strength Fe lines whose formation depth in the photosphere is very deep and differ greatly from the Ba ii line forming depths. Accordingly, we argue that the Ba abundances determined from the