settingwastransformedtoback-arcextension;inducingintensepartialmeltingofthelowercrustatca.158MaandresultinginthemostfrequentgraniticmagmaticactivityintheSouthChinahinterland.Whenslabfounderingoccurredatca.140Ma;underplatingofmantle-derivedmagmascausedmeltingofthecontinentalcrust;generatingextensivehighlyfractionatedgranite...