One almost wonders if he’s intentionally riffing on Auden’s ‘In Praise of Limestone’ (ht MS):

Whatever may be meant by moral landscape,
it is for me increasingly a terrain
seen in cross-section: igneous, sedimentary,
conglomerate, metamorphic rock-
strata, in which particular grace,
individual love, decency, endurance,
are traceable across the faults.