The Luzong basin locates at northeastern margin of the Yangtze craton and the foreland area of the Dabie-Sulu orogen,  and convergent section of the Tanlu fault and the Yangtze River fault,  is a typical tectonic place.  In this paper,  the authors used zircon SHRIMP U-Pb technique accurately dating samples from four Formations in the Luzong Basin,  yield emplacement ages of (131±1) Ma,  (133±1) Ma,  (130±1) Ma and (127±1) Ma, respectively,  show that whole volcanic rocks in the Luzong Basin formed in a very short period of time (≤6 Ma). These data,  combined with the time of whole volcanism in the Middle and Lower Yangtze River reaches,  predicate an “sudden” volcanic event,  imply delamination as the main model for lithospheric thinning of the region (and the whole lower Yangtze region).