Serpentines, peridotites and diabases are interstratified with the Eocene deposits.
They include gypsum, dolomite, conglomerates, phyllites, and a basic series of eruptive rocks (gabbros, peridotites, serpentines).
This may explain why alkali basalts carry mostly spinel peridotites although the magma originated at deeper depth of garnet peridotites zone.
spinel peridotites although the magma originated at deeper depth of garnet peridotites zone.