West Norwegian 'diamond facies' eclogite contains tiny mineral inclusions of quartz and amphibole lamellae that are not stable in the diamond field. Low trace amounts of water in the lamellae-bearing host minerals suggest that the inclusion microstructure was not formed by fluid infiltration but by dehydration during early exhumation of these rocks. Some samples with higher water content argue that a late fluid overprint was spatially restricted and obliterated evidence of extreme metamorphism.

Quantitative climate reconstructions based on pollen and brGDGTs reveal, for the Late Glacial, a warm Bølling–Allerød and a marked cold Younger Dryas in Italy, showing no latitudinal differences in terms of temperatures across Italy. In terms of precipitation, no latitudinal differences are recorded during the Bølling–Allerød, whereas 40–42° N appears as a key junction point between wetter conditions in southern Italy and drier conditions in northern Italy during the Younger Dryas.

Carbonates reduce the melting point of the mantle, and carbonate melts produced in low-degree melting of a carbonated mantle are considered the precursor of CO₂-rich magmas. We established experimentally the melting relations of carbonates up to 9 GPa, showing that Mg-carbonates melt incongruently to periclase and carbonate melt. The trace element signature of carbonate melts parental to kimberlites is approached by melting of Mg-rich carbonates.

The equilibrium phase of A + HP clinoenstatite = forsterite + water was experimentally investigated at aH₂O = 1 in situ. In cold subducting slabs, it is of relevance to transport water to large depths, initiating the formation of dense hydrous magnesium silicate (DHMS). At normal gradients, the huge water amount from this reaction induces important processes within the overlying mantle wedge. We additionally discuss the relevance of this reaction for intermediate-depth earthquake formation.

Dense hydrous magnesium silicates, like the 3.65 Å phase, are thought to cause deep earthquakes. We investigated the dehydration of the 3.65 Å phase at P and T. In both directions of the investigated simple reaction, additional metastable water-rich phases occur. The observed extreme reduction in grain size in the dehydration experiments might cause mechanical instabilities in the Earth’s mantle and, finally, induce earthquakes.