Figure 3. Variation curves of sea-water Sr isotopic composition in the Precambrian, (1) from published data [Asmerom et al., 1991; Brasier and Lindsay, 1998; Derry and Jacobsen, 1988; Derry et al., 1992; Faure, 1986; Gorokhov et al., 1995, 1998; Hall and Veizer, 1996; Kuznetsov et al., 1997, 2000\link{28; Mirota and Veizer, 1994; Pokrovsky and Vinogradov, 1991; Semikhatov et al., 1998; Veizer et al., 1992a, 1992b; Vinogradov et al., 1998] and in the Baikit (2) and Yenisei (3) basins, Eastern Siberia. A and B, alternative options for chronological assignment of the 87Sr/86Sr curve for the Baikit basin.