In this figure we illustrate two more late G-giant stars with abundance peculiarities. 37 Com is a G9 III with an abnormally weak G-band, but quite normal CN 4216 band. HD217143 is a G9.5 III with an enhanced Ba II 4554 line. Enhanced abundances of carbon and s-process elements such as barium are believed to be due to "dredge-up", in which deep convection currents in the star actually dredge nuclear-processed material from the outer core up into the atmosphere of the star.
This figure uses 3.6 Å resolution flux spectra.