SPINEL LHERZOLITE
Here's a sample of mantle rock. This
spinel lherzolite is a xenolith nodule in basalt lava that was erupted from the
Mt. Leura Volcano in Victoria, Australia. The rock was plucked from deep wall
rocks during the ascent of basaltic magma during the Late Pleistocene.
Published research on xenoliths from this locality indicates they are from the
lithospheric mantle (below the Moho & above the asthenosphere). The
spinel lherzolite itself is a variety of peridotite, an ultramafic, intrusive
igneous rock. It has greenish forsterite olivine, blackish pyroxene, and
dark spinel.
Locality & geology - Mt. Leura Complex, a maar/tuff-ring volcano in the
Newer Volcanics Province (a Jurassic to Quaternary magmatic province in
southeastern Australia having intermittent, low-volume eruptive activity),
eastern side of town of Camperdown, southwestern Victoria, southeastern
Australia.
Age -
spinel lherzolite xenolith is Neoproterozoic in age; the surrounding basalt
lava is late Late Pleistocene in age (22 ky).
Spinel lherzolite (wet, cut surface; 5.8 cm across at its widest) - a
Neoproterozoic-aged mantle xenolith in Pleistocene basalt from Mt. Leura,
Victoria, Australia. The lava & enclosed xenolith were erupted about
22 thousand years ago.