Fig. 4From: Using geophysical logs to identify Milankovitch cycles and to calculate net primary productivity (NPP) of the Late Permian coals, western Guizhou, ChinaThe precise period division of the 18# coal seam by wavelet analysis. L, M and S represent Milankovitch periodicities of 123 kyr (eccentricity), 35.6 kyr (obliquity), and 21.2 kyr (precession), respectivelyBack to article page