Fig. 5

New δ13C and δ15N values of human and animal samples recovered from the Guanzhong Basin and the mean ± SD δ13C and δ15N values of previous human samples from 73 sites in Northern China and surrounding regions during around 550 BC–AD 1200 (2570–820 B.P.) (Atahan et al., 2014; Dong et al., 2007, 2017; Gu, 2007; Guo et al., 2020; Hou et al., 2012, 2017, 2019; Hou & Gu, 2018; Li et al., 2020; Ling et al., 2010, 2019; Ling, 2010; Liu et al., 2021; Ma et al., 2016a, b; Machicek, 2011; Pan et al., 2009; Sheng et al., 2020; Si et al., 2013; Tang et al., 2018; Tao et al., 2020a, b; Wang et al., 2016; Wang et al., 2018; Wilkin et al., 2020; Xue, 2015; Zhang, 2003; Zhang, 2006; Zhang & Li, 2006; Zhang et al., 2009; Zhang et al., 2010; Zhang et al., 2012; Zhang et al., 2013, 2015, 2017; Zhang Q et al., 2018; Zhang X et al., 2018; Zhang, 2019; Zhou, 2016; Zhou et al., 2017; Zhou & Mijiddorj, 2020; Zhou et al., 2020; Zhu et al., 2020).