  (Abridged) It is shown that a semi-quantitative agreement with the gross
solar r-process abundance pattern near and above mass number A=130 can be
obtained by a superposition of two distinctive kinds of supernova r-process
events. These correspond to a low frequency case L and a high frequency case H,
which takes into account the low abundance of I129 and the high abundance of
Hf182 in the early solar nebula. The lifetime of Hf182 associates the events in
case H with the most common Type II supernovae. These events would be mainly
responsible for the r-process nuclei near and above A=195. They would also make
a significant amount of the nuclei between A=130 and 195, including Hf182, but
very little I129. In order to match the solar r-process abundance pattern and
to satisfy the I129 and Hf182 constraints, the events in case L, which would
make the r-process nuclei near A=130 and the bulk of those between A=130 and
195, must occur 10 times less frequently but eject 10--20 times more r-process
material in each event. We speculate that the usual neutron star remnants, and
hence prolonged ejection of r-process material, are associated with the events
in case L, whereas the more frequently occurring events in case H have ejection
of other r-process material terminated by black hole formation during the
neutrino cooling phase of the protoneutron star.
