We have extended our earlier simulations of the high temperature behaviour of
lattice QCD with two light flavours of staggered quarks on a 163×8
lattice to lower quark mass (m_q=0.00625). The transition from hadronic matter
to a quark-gluon plasma is observed at 6/g2=5.49(2) corresponding to a
temperature of Tc≈140MeV. We present measurements of observables
which probe the nature of the quark-gluon plasma and serve to distinguish it
from hadronic matter. Although the transition is quite abrupt, we have seen no
indications that it is first order.Comment: 23 pages, RevteX, 6 encapsulated postscript figure