But under condition of slow cooling the first formed minerals are unstable at the lower temperatures and so react with the remaining magma to form new minerals.
(the first formed minerals; are; unstable; L:at the lower temperatures; L:under condition of slow cooling) (the first formed minerals; react; with the remaining magma)
the first formed minerals the first formed minerals
are react
unstable L:at the lower temperatures L:under condition of slow cooling
with the remaining magma