  We present results of an investigation on a high-galactic latitude sample of
late-type field stars selected from the ROSAT All-Sky Survey (RASS). The sample
comprises about 200 G, K, and M stars. Lithium abundances were determined for
about 180 G-M stars. Radial velocities were measured for most of the circ. 140
G and K type stars. Combined with proper motions these data were used to study
the age distribution and the kinematical properties of the sample. Based on the
lithium abundances half of the G-K stars were found to be younger than the
Hyades (660 Myr). About 30% are comparable in age to the Pleiades (100 Myr). A
small subsample of 10 stars is younger than the Pleiades (100 Myr). They are
therefore most likely pre-main sequence stars. Kinematically the PMS and
Pleiades-type stars appear to form a group with space velocities close to the
Castor moving group but clearly distinct from the Local Association.
