  Magnetization M(T,H) measurements performed on thoroughly characterized
commercial amorphous carbon powder doped with sulfur (AC-S), revealed the
occurrence of an inhomogeneous superconductivity (SC) below T_c = 38 K. The
constructed magnetic field-temperature (H-T) phase diagram resembles that of
type-II superconductors. However, AC-S demonstrates a number of anomalies. In
particular, we observed (1) a non-monotonic behavior of the lower critical
field H_c1(T); (2) a pronounced positive curvature of the "upper critical field
boundary" that we associated with the flux lattice melting line Hm(T); (3) a
spontaneous ferromagnetic-like magnetization M0 coexisting with SC. Based on
the analysis of experimental results we propose a nonstandard SC state in AC-S.
