The Earth's lower mantle constitutes more than
50% of Earth's volume and it plays a pivotal role
in the evolution and present-day dynamics of our
planet. Despite its importance, our knowledge
about the state of the lower mantle is still only
fragmentary.
A number of recent seismological observations,
including low velocity zones in the lowermost
mantle or seismic anisotropy in D'', enhanced our
knowledge of the structure and dynamics of the
deep mantle. In addition, laboratory experiments
and computational studies, carried out under
simulated Earth mantle conditions, impacted our
understanding of the physical and chemical
behaviour of deep mantle phases at relevant P-T
conditions and their relation to the
seismological observables. The recent
experimental discovery of the spin transition of
iron at conditions corresponding to the lower
mantle, for instance, questions our traditional
view of a chemically homogenous lower mantle.
Also, recent results from computational
mineralogy on the physical and chemical
properties of post-perovskite, presumably the
major phase in the lowermost mantle, changed our
understanding of the enigmatic D'' layer at the
bottom of the lower mantle.
Our improving capabilities to monitor the deep
Earth with seismic waves, derive physical and
chemical properties of potential mantle phases
using both experimental and computational
approaches, and model geodynamic processes,
promise to further enhance our understanding of
this important part of our planet. The
overwhelming complexity of the Earth mantle,
however, demands for a multidisciplinary approach
in order to proceed towards an integrated picture
of the Earth lower mantle, which best satisfies
the constraints that emerge from the various
disciplines.

This session aims at contributions from mineral
physics (both experimental and computational),
geochemistry, seismology, and geodynamics, which
enhance our knowledge about the composition,
structure, dynamics, and evolution of the Earth
lower mantle.