Figure 4

Geographic map showing sample sites in Heshui, Lantian and Xi’an and the distribution of compiled modern leaf wax δDn-alkane values of higher plants across the North hemisphere.
Black rectangles are data based upon Liu and Yang, (2008); red dots are additional data points. (Fig. 4 was created by CorelDRAW 12; My co-authors and I grant NPG to publish the image under an Open Acess license; We grant NPG to publish the image in all formats i.e. print and digital).