The middle crust and the lower crust is in the ductile field.

上地壳表现为脆性变形，中、下地壳为韧性的流动变形。

youdao

In lower crust, faults often consist of a series of secondary fractures.

发育于地壳浅层中的脆性断层常常由一系列次级小断层所构成。

youdao

The faulting might be attributed to the ascending lower crust-derived fluids after the Late Miocene epoch.

造成断裂分期活动的原因是藏东地区下地壳流体的存在。

youdao

There were servants to address one's every material need, dinner in white tie and lavish gowns, and rules designed to keep the upper crust on top and the lower classes in their place.

CNN: 'Downton' in America: 6 big estates

As exotic-auto makers redefine what a superluxury car can be, their executives are attempting a delicate balancing act: maintaining the exclusive cachet of their upper-crust brands while pursuing new wealthy customers that lower-end luxury rivals are currently scooping up.

WSJ: Handcrafted Cars Geared for Soccer Moms

And those estimates are of what mining companies have concrete plans to get at numbers that are significantly lower than the colossal quantities of reserves buried throughout the Earth's crust.

WSJ: Exhausting the Earth's Resources? Not So Fast