<p>Four original monomineral methods for mantle peridotite associations are used to reconstruct <em>P</em>–<em>T</em> conditions beneath the kimberlite pipes of Yakutia. The clinopyroxene Jd–Di method gives the closest coincidence with Opx
barometry in accord with all physico-chemical boundaries. Garnet thermometers calibrated using Opx, Gar–Cpx and Ni-garnet
thermometers and two variants of barometers were developed separately for pyroxenites and peridotites. A Cr–Sp thermobarometer
uses the monomineralic version of the Ol–Sp thermometer and a newly calibrated Cr–Sp barometer. A picroilmenite method uses
the Ol–Sp thermometer and a pressure-calibration of the geikielite component. Each mantle column is divided into two (upper
and lower) sections by a pyroxenite layer located near 40 kbar. Below the pyroxenite layer, the lower section comprises 3–4
lithologically distinct horizons, with a thermally perturbed layer at the base. Above the pyroxenite layer are 3–5 lithologically
distinct horizons, which are more fertile than the lower sections. Splitting of the geotherms characterizes most <em>P</em>–<em>T</em> diagrams and is ascribed to multistage melt percolation processes typical for the mantle beneath kimberlite pipes. The largest
pipes are diamond-bearing and have a highly depleted peridotite lens above the asthenospheric layer.
</p
