The Early Cambrian Niutitang Formation on the Yangtze Block is a set of high-quality marine source rock. However, hydrocarbon-forming organisms of these organic-rich shales was poorly understood. In this paper, the results of palynofacies analysis and hydrocarbon-forming organism char-acteristics of the Niutitang Formation from the Yangtze Block are reported for the first time, and the sedimentary environment is discussed in combination with geochemical data. Palynofacies analysis show that the organic matter (OM) of the Niutitang Formation is mainly composed of amorphous or-ganic matter (AOM), with a small amount of structural organic matter (STOM) and palynomorphs (PL). The results of CONISS (stratigraphically constrained incremental sum of squares) cluster analysis show that the PL can be divided into three zones in the ascending order:Leiosphaeridia-Micrhystridium-fungal zone, algal bloom zone and fungal development zone, corresponding to three stages:transgres-sion, high-stand and regression, respectively. The principal component analysis (PCA) shows that the main hydrocarbon-forming organisms include planktonic green microalgae or dinoflagellates that are related to Leiosphaeridia and Microcystidium. Palynofacies analysis and geochemical data show that the Niutitang Formation was deposited under anoxic or dysoxic condition which was favorable to the en-richment of organic matter.

State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China;School of Earth Sciences,China University of Geosciences,Wuhan 430074,China;College of Urban and Environmental Sciences,Hubei Normal University,Huangshi 435002,China

[1]Hong Wei;Qinglai Feng;Jianxin Yu;Shan Chang-.Characteristics and Sources of Organic Matter from the Early Cambrian Niutitang Formtion and Its Preservation Environment in Guizhou)[J].地球科学学刊（英文版）,2022(04):933-944

Niutitang,Formtion,palynofacies,Palynofacies,STOM,palynomorphs,CONISS,stratigraphically,Leiosphaeridia,Micrhystridium,transgres,Microcystidium,dysoxic

Characteristics,Sources,Organic,Matter,from,Early,Cambrian,Its,Preservation,Environment,Guizhou,Formation,Yangtze,Block,set,high,quality,marine,source,rock,However,hydrocarbon,forming,organisms,these,organic,shales,was,poorly,understood,In,this,paper,results,analysis,char,reported,first,sedimentary,environment,discussed,combination,geochemical,data,that,matter,mainly,composed,amorphous,AOM,small,amount,structural,PL,constrained,incremental,sum,squares,cluster,can,be,divided,into,three,zones,ascending,order,fungal,algal,bloom,development,corresponding,stages,stand,regression,respectively,principal,component,shows,include,planktonic,green,microalgae,dinoflagellates,related,deposited,anoxic,condition,which,favorable,richment

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