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
通过青藏高原中部兹格塘错湖泊沉积物总碳（TC）、总有机碳（TOC）、总氮（TN）、总硫（TS）、氢指数（HI）、氧指数（OI）和有机质的碳同位素（δ^13Corg）等多项指标的综合分析,在判断沉积物中有机质来源的基础上,根据各指标的变化特...通过青藏高原中部兹格塘错湖泊沉积物总碳（TC）、总有机碳（TOC）、总氮（TN）、总硫（TS）、氢指数（HI）、氧指数（OI）和有机质的碳同位素（δ^13Corg）等多项指标的综合分析,在判断沉积物中有机质来源的基础上,根据各指标的变化特征阐明了各自的气候指示意义,建立了兹格塘错全新世以来的古气候演化序列.10100 cal a BP兹格塘错地区进入全新世,全新世早中期为暖湿气候特征,在8600～8400和7400～7000 cal a BP发生两次强烈冷事件;中晚全新世以来气候变冷变干.这一气候演化过程与其邻近的错鄂的研究结果相近,代表了青藏高原中部全新世的气候演化特点.青藏高原中部全新世气候变化主要受太阳辐射控制.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.
文摘通过青藏高原中部兹格塘错湖泊沉积物总碳（TC）、总有机碳（TOC）、总氮（TN）、总硫（TS）、氢指数（HI）、氧指数（OI）和有机质的碳同位素（δ^13Corg）等多项指标的综合分析,在判断沉积物中有机质来源的基础上,根据各指标的变化特征阐明了各自的气候指示意义,建立了兹格塘错全新世以来的古气候演化序列.10100 cal a BP兹格塘错地区进入全新世,全新世早中期为暖湿气候特征,在8600～8400和7400～7000 cal a BP发生两次强烈冷事件;中晚全新世以来气候变冷变干.这一气候演化过程与其邻近的错鄂的研究结果相近,代表了青藏高原中部全新世的气候演化特点.青藏高原中部全新世气候变化主要受太阳辐射控制.
