Recent studies show that the Cretaceous intracontinental and arc tectonomagmatism in Northeast Asia resulted from the intracontinental mantle plume under the North China Craton and its channel-like flow that was dragged into the underneath of the ancient arc, respectively. Although the southwest-to-northeast migration of the channel-like flow in the mantle wedge might have occurred along the Cretaceous margin from southeast China to southwest Japan, adakites, implying partial melting of the subducted oceanic crust, were only observed along southwest Japan. To understand the localized adakite occurrences, a three-dimensional numerical subduction model which covers the margin from southeast China to southwest Japan through the present East China Sea was formulated by considering the southwest-to-northeast migration of the channel-like flow in the mantle wedge. Our model calculations show that increased slab-surface temperatures under southeast China by the channel-like flow were lower than the solidus of the hydrated oceanic crust; no adakites were generated in southeast China. In contrast to that in southeast China, younging subducting slab from the Early to Late Cretaceous along the eastern East China Sea and southwest Japan allowed the channel-like flow to increase the slab-surface temperatures over the solidus; adakites were generated in the eastern East China Sea and southwest Japan. Our model calculations are consistent with the adakite occurrences in southwest Japan and the occurrences in the eastern East China Sea can be verified via oceanic drilling.
All Science Journal Classification (ASJC) codes
- Environmental Science(all)
- Earth and Planetary Sciences(all)