This study provides δ^13C profiles from a lower-slope(Well ZK102)to basin(Bahuang Section)environment to better understand the temporal and spatial variability in δ^13Ccarb-δ^13Corg of the Yangtze Block during the ...This study provides δ^13C profiles from a lower-slope(Well ZK102)to basin(Bahuang Section)environment to better understand the temporal and spatial variability in δ^13Ccarb-δ^13Corg of the Yangtze Block during the Late Ediacaran.Our new δ^13C profiles together with the reported data suggest that the Upper Ediacaran successions from different depositional environments are generally bounded by negative δ^13Ccarb and/or δ^13Corg excursions in the underlying and overlying strata.Moreover,the Upper Ediacaran δ^13Ccarb profiles generally can be subdivided into two positive excursions and an interjacent negative excursion,whereas the paired δ^13Corg profiles from different depositional environments have individual variation trends.On the other hand,these data show a large surface-to-deep waterδ^13C gradient(~5‰variation in δ^13Ccarb,>10‰variation in δ^13Corg)which can be reasonably explained by the heterogeneity of the biological activities in the redox-stratified water column.Furthermore,the decoupled δ^13Ccarb-δ^13Corg pattern with large δ^13Corg perturbations at the lower slope precluded the existence of a large dissolved organic carbon reservoir at the Yangtze Block during the Late Ediacaran.Thus,the high δ^13Ccarb values in the Upper Ediacaran succession could be balanced by large amounts of buried organic carbon likely associated with high productivity.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.41472089,U1663209)the Open Research Fund Program of Hunan Provincial Key Laboratory of Shale Gas Resource Utilization,Hunan University of Science and Technology.
文摘This study provides δ^13C profiles from a lower-slope(Well ZK102)to basin(Bahuang Section)environment to better understand the temporal and spatial variability in δ^13Ccarb-δ^13Corg of the Yangtze Block during the Late Ediacaran.Our new δ^13C profiles together with the reported data suggest that the Upper Ediacaran successions from different depositional environments are generally bounded by negative δ^13Ccarb and/or δ^13Corg excursions in the underlying and overlying strata.Moreover,the Upper Ediacaran δ^13Ccarb profiles generally can be subdivided into two positive excursions and an interjacent negative excursion,whereas the paired δ^13Corg profiles from different depositional environments have individual variation trends.On the other hand,these data show a large surface-to-deep waterδ^13C gradient(~5‰variation in δ^13Ccarb,>10‰variation in δ^13Corg)which can be reasonably explained by the heterogeneity of the biological activities in the redox-stratified water column.Furthermore,the decoupled δ^13Ccarb-δ^13Corg pattern with large δ^13Corg perturbations at the lower slope precluded the existence of a large dissolved organic carbon reservoir at the Yangtze Block during the Late Ediacaran.Thus,the high δ^13Ccarb values in the Upper Ediacaran succession could be balanced by large amounts of buried organic carbon likely associated with high productivity.
