ReportedinthispaperaretheNdisotopiccompositionsofthepre-SinianandSinian-CambriansedimentaryrocksintheXiushuiarea,JiangxiProvince.SignificantdifferencesarenoticedbetweenthemintheirNdisotopicdompositions.Asforthepre-Sinianlightlymetmorphozedsedimentaryrocks,^143Nd/^144Nd=0.512000-0.512214,CNd(T)=-8.04-9.99,andTDM=18332426MaaresuggestedfortheSinian-Cambriansedimentaryrocks.ThesedifferenceswouldreflectthepersityofmaterialsourceforthesedimentaryrocksdepositedbeforeandaftertheSinianperiod.Mantlematerialap-pearstohavebeeninvolvedintheformationofthepre-Siniansedimentaryrockswhilethepost-Siniansedimentaryrocksarecomposedmainlyofrecycleddetritusfromthecontinentalcrust.
