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 k.y.).
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.