Studies on Sr-Nd isotopic ratios and element compositions for the mafic rocks from Jiaoziyan plutons and Pb isotopic ratios for the mafic rocks from Jiaoziyan and Shacun plutons show that(87Sr/86 Sr)i = 0.7072 - 0.7075, εNd(t) = - 10.4- - 11.9, (206Pb/204Pb)i = 16.464 - 17.394, (207Pb/204Pb)i = 15.349 - 15.453, (208Pb/204Pb)i = 37.338 - 37.976. These isotopic compositions imply that the contribution of the lower crust to the mantle source is very important; especially that Pb isotope composition indicates that the contribution come from Dabie lower crust itself. The mechanism of addition of the lower crustal material into the mantle maybe relate to delamination.
|Number of pages||11|
|Journal||Acta Petrologica Sinica|
|Publication status||Published - 2008|
- Lower crust
- Mafic rocks
- North Dabie
- Pb-Sr-Nd isotope