[en] The appearance of oxygen vacancies in a surface of strontium titanate has been recently identified to be a likely reason for the formation of a two-dimensional electron gas close to the surface. Lately the first SARPES measurements on these surfaces unveiled an interesting spin texture which shows besides the expected Rashba effect a huge spin splitting that can not be attributed to spin-orbit interaction. Employing density functional theory we therefore examined oxygen deficient slabs and found that indeed magnetism is capable of explaining the measured spin splittings. Moreover we obtain a very rich spin texture where we find not only rotating spins due to the Rashba interaction, but a very complex spin structure most likely caused by an interplay of orbital and spin degrees of freedom.