Geological controls on palaeo-environmental change in a tectonic rain shadow, southern New Zealand

► A pronounced tectonic-orographic rain shadow developed in the Pliocene. ► Rising antiformal ranges exposed substrates that caused salination and coal fires. ► Uplift, salination, and fires exacerbated ecological change during aridification. ► Surface environmental rejuvenation occurred laterally at 1-10 m/thousand years. ► Mountain uplift caused isolation and extreme speciation of freshwater fish.