0 relating to the hard outer surface of the earth:
crustal displacement
Furthermore, crustal deformation associated with tectonic uplift and exposure of ancient basins often disrupts the lateral continuity of stratigraphic indicators and renders their correlation problematic.
Although not mentioned in the text, crustal rebound as the weight of ice is removed might make the difference in this scenario as it develops.
The derivation from or contamination with crustal material explains the observed similarity of the multi-element patterns to typical upper continental crust.
With all these processes, interactions between mantle-derived and crustal-derived magmas control the nature of magmatism in the complex.
This is valid also for variations among the basaltic members, implying either a heterogeneous mantle source or varying components of crustal contamination.
Deciphering mantle and crustal signatures in subduction zone magmatism.
Moreover, the crustal thickness has apparently been augmented over one hemisphere by up to 20 km or so, gradually tapering off near the hemisphere boundaries.
At shallow crustal levels, extension can be taken up by tension fractures that sole out onto a normal fault-plane at depth.