To gain insight into the rheology of selected feldspar-bearing rocks from the continental lower crust (CLC), three granulites from exposed lower crustal terrains and a microgabbro have been deformed to ca. ~10% strain at confining pressures of 0.8–1.0 GPa, temperatures of 600–900°C, and constant strain-rates of 10 −4−10 −7 s −1. The most extensive work was done on the mafic Pikwitonei and felsic Adirondack granulites. The Pikwitonei (Mg-hornblende-plag (An 70−2 px) has only a limited T,ϵ range of apparent steady-state behavior, and strain-softens at T ⩾ 800° C at ϵ = 10 −5−10 −6 s −1, apparently associated with developing shear zones. This strain-softening is pressure-insensitive from P c = 0.8–1.0 GPa at T = 850° C, ϵ = 10 −6 s −1 even though the dominant strain accommodation mechanisms change from semibrittle/cataclastic to crystal plastic (including dynamic recrystallization) with increasing pressure. Plagioclase appears to bear more of the creep strain than amphibole at most experimental conditions except in those runs where both plagioclase and amphibole recrystallization occurs. Kapuskasing (plag-cpx-gt) granulite, deformed at 800°C and at 850°C, 10 −6 s −1 has deformed in the steady-state at stress levels only slightly greater than the Pikwitonei. The Stillwater microgabbro and Adirondack granulite are appreciably weaker and the latter exhibits homogeneous semibrittle steady-state behavior over the entire range of conditions investigated. For the Adirondack (2 felds-2 px-gt-qtz) granulite, quartz (21%) appears to control the creep rate at these low strains, and steady-state mechanical data fit well a creep power law with A = 8 × 10 −3 MPa − n s −1, Q c = 243 kJ/mol and n = 3.1. Extrapolation of this flow law and of preliminary power law creep relations for the Pikwitonei and microgabbro to a range of physical conditions assumed to encompass those at the continental Moho supports geological and geophysical inferences that a mechanical discontinuity occurs at this transition zone, with the lower crust generally being the weaker material. In addition, the stain-softening exhibited by the Pikwitonei may bear directly on the development of detachment zones at mid- to lower-crustal depths during prograde metamorphism.