Lithium deficient halo stars: abundance trends and enhanced rotation

We present results from a high resolution study of six Li-depleted halo dwarfs. These stars exhibit Lithium abundances more than 0.5 dex below the Spite Plateau. The study is comprised of two parts: 1) a detailed abundance analysis covering many light, alpha, Fe-peak and neutron capture elements and 2) a study of rotational line broadening. We find that there are no common abundance anomalies, other than the Lithium depletion, that distinguish these stars from the Li-normal population. Four of the six stars however, show evidence of abnormally high projected rotation velocities. These findings support a non-standard depletion mechanism in Li-depleted halo stars, and emphasize their necessary exclusion from future studies of the Spite Plateau.