The previous chapter discussed the thermal regime of the lithosphere constrained by borehole heat flow measurements; the present chapter focuses on other methods to assess lithospheric temperatures. These include conversion of physical parameters measured in remote geophysical sampling, such as seismic velocities, seismic attenuation, and electrical conductivity, into the temperature of the crust and the upper mantle. The chapter also discusses magnetic methods for determining depth to the Curie point and lithospheric geotherms, while other approaches that provide additional information on the thermal state of the lithosphere (such as apatite fission track analysis, data from metamorphic core complexes, and data on temporal variations in magmatism) are excluded from the discussion.

Mantle xenoliths provide invaluable constraints both on lithosphere composition and its thermal structure, in particular in Precambrian terranes. Uneven worldwide coverage by highresolution geophysical and mantle xenolith data makes comparison of different approaches for estimating mantle temperatures (or calibrating models) difficult in many regions (Table 5.1). The major reference books on petrologic studies of mantle xenoliths are Nixon (1987) and Pearson et al. (2003). Chapter 6 discusses petrologic studies of mantle xenoliths related to density of the lithospheric mantle, the chemical boundary layer, and the tectosphere, which closely links thermal and compositional anomalies in the cratonic lithospheric mantle.