中国科学院南京地质古生物研究所机构知识库

Lack of high quality zircon U-Pb age data has hampered us from ascertaining the relative positions of various continental blocks within East Gondwana, which also resulted in age-fossil inconsistencies in the Neoproterozoic successions particularly within India Peninsular region. By means of analyzing detrital zircons from the Neoproterozoic sedimentary rocks of Peninsular India and NW Australia, we found similar age spectra among NW India, Himalaya, NW Australia and Cathaysia Block that are indications of their proximity with each other. A scenario can be envisaged that following delivery of detritus (1.3-1.1 Ga) to northern India during early to middle Ediacaran Period, South China together with Australia probably clockwise rotated during late Ediacaran to Cambrian Period which prompted South China to receive detritus (1.3-1.1 Ga) from Western and northwestern Australia. New radiometric dates suggest an Ediacaran age for the Marwar and Bhander groups, thus confirming previous biostratigraphic correlations among the Marwar, Kurnool, Bhima and Bhander Groups. Given their diverse age spectra, the Maihar Sandstone and the Sonia Sandstone were possibly deposited in different time intervals/slices. Uncertainties in obtaining the youngest age of detrital zircons mean care must be taken when using detrital zircon age for tectonic regime classification.