Paleo-sedimentary environmental restoration and its significance of Chang 7 Member of Triassic Yanchang Formation in Ordos Basin, NW China
Jinhua FU,Shixiang LI,Liming XU,Xiaobing NIU
Table 1 Statistics on geochemical elements and element ratios of the Yanchang Formation in the Ordos Basin.
Horizon B/10-6 CaO/MgO?Al2O3 Sr/Ba V/(V+Ni) Th/U Sr/Cu Rb/K2O Rb/Sr
Chang 9-
Chang 8 Member		 8.1-74.3
34.13(30)		 0.057-0.295
0.139(30)		 0.21-1.94
0.44(30)		 0.56-0.91
0.76(30)		 1.34-14.54
6.38(30)		 2.52-25.24
7.09(30)		 2.86-6.21
4.18(29)		 0.07-1.66
0.62(30)
Chang 73
Submember		 3.1-87.6
33.25(82)		 0.001-0.514
0.101(82)		 0.06-0.94
0.38(80)		 0.51-0.97
0.79(82)		 0.28-12.38
4.48(52)		 0.88-29.37
8.19(50)		 2.52-7.37
4.41(81)		 0.01-6.72
0.69(83)
Chang 72
Submember		 3.05-78.9
32.10(76)		 0.002-0.313
0.112(76)		 0.07-0.88
0.34(79)		 0.68-0.97
0.78(76)		 0.28-9.77
5.26(61)		 1.75-28.22
7.20(61)		 2.52-7.57
4.30(76)		 0.12-2.15
0.63(76)
Chang 71
Submember		 7.25-86.4
32.67(76)		 0.027-0.239
0.125(77)		 0.13-0.91
0.33(80)		 0.59-0.91
0.77(76)		 0.96-15.67
6.10(62)		 2.54-26.70
6.71(62)		 1.70-7.11
4.11(77)		 0.07-2.28
0.70(77)
Chang 7
Member		 3.05-87.6
32.69(234)		 0.001-0.514
0.112(235)		 0.06-0.94
0.35(239)		 0.51-0.97
0.78(234)		 0.28-15.57
5.33(175)		 0.88-29.37
7.31(174)		 1.70-7.57
4.28(234)		 0.01-6.72
0.67(236)
Chang 6-
Chang 1 Member		 9.95-104
46.29(16)		 0.067-0.213
0.148(16)		 0.19-0.73
0.38(16)		 0.70-0.89
0.75(16)		 3.11-9.21
6.43(16)		 2.17-23.78
7.44(16)		 3.28-5.87
4.42(16)		 0.25-2.23
0.68(16)
Yanchang
Formation		 3.05-104
33.62(280)		 0.001-0.514
0.117(282)		 0.06-1.94
0.36(285)		 0.51-0.97
0.78(280)		 0.28-15.67
5.55(221)		 0.88-29.37
7.24(220)		 1.70-7.57
4.27(280)		 0.01-6.72
0.66(283)