  We report the detection of the SiO (J = 2 - 1) transition from the massive
cold dense core G333.125-0.562. The core remains undetected at wavelengths
shorter than 70 micron and has compact 1.2 mm dust continuum. The SiO emission
is localised to the core. The observations are part of a continuing
multi-molecular line survey of the giant molecular cloud G333. Other detected
molecules in the core include 13CO, C18O, CS, HCO+, HCN, HNC, CH3OH, N2H+, SO,
HC3N, NH3, and some of their isotopes. In addition, from NH3 (1,1) and (2,2)
inversion lines, we obtain a temperature of 13 K. From fitting to the spectral
energy distribution we obtain a colour temperature of 18 K and a gas mass of 2
x 10^3 solar mass. We have also detected a 22 GHz water maser in the core,
together with methanol maser emission, suggesting the core will host massive
star formation. We hypothesise that the SiO emission arises from shocks
associated with an outflow in the cold core.

Astrophysics