Effects of astronomical orbital cycle and volcanic activity on organic carbon accumulation during Late Ordovician-Early Silurian in the Upper Yangtze area, South China

ZHANG Xi,ZHANG Tingshan,ZHAO Xiaoming,ZHU Haihua,MIHAI Emilian Popa,CHEN Lei,YONG Jinjie,XIAO Qiang,LI Hongjiao

Fig. 3. The δ13C and CIA values spectral analysis of Upper Katian-Lower Rhuddanian in Jienietuo section and Lücongpo section. E—long eccentricity cycle; e—short eccentricity cycle; o—obliquity cycle; p—precession cycle.