Complex sentence: Flexural uplift is not typically associated with rift flank uplift, but in the case of the Transantarctic Mountains it occurs at the same lithospheric boundary, here in conjunction with thermal expansion of the mountain belt results in very rapid surface uplift.
Split into simpler sentences: Flexural uplift is not typically associated with rift flank uplift, but in the case of the Transantarctic Mountains it occurs at the same lithospheric boundary. This in conjunction with thermal expansion of the mountain belt results in very rapid surface uplift.