“…First, for the matrix dolomites, 87 Sr/ 86 Sr ratio decreases from the RD1 (n ¼ 4, mean ¼ 0.70986, s ¼ 0.000404) (0.709307-0.710297) to RD2 (n ¼ 2, mean ¼ 0.709235, s ¼ 0.000066) (0.709188-0.709281) dolomites ( (Burke et al, 1982;Nicholas, 1996;Montañ ez et al, 2000;Sial et al, 2008). In contrast, the values of Well Tong 1 are greater, suggesting that these dolomites may be affected by burial diagenesis or secondary alteration, because the 87 Sr/ 86 Sr ratio can increase with time and burial depth (e.g., Mountjoy et al, 1992;Qing, 1998;Gregg et al, 2001;Duggan et al, 2001;Chen et al, 2004). The 87 Sr/ 86 Sr ratios of the RD2 dolomites are lower than those of the RD1 dolomites, indicating recrystallization of the RD2 dolomites by fluids with lower 87 Sr/ 86 Sr ratios (Durocher and Al-Aasm, 1997;Machel, 1997) in equilibrium with the underlying Middle Cambrian evaporites because Middle Cambrian water has low 87 Sr/ 86 Sr ratios (Burke et al, 1982;Nicholas, 1996;Montañ ez et al, 2000;Sial et al, 2008) (Fig.…”