Geochronology and Geochemistry of the Karadaban Bimodal Volcanic Rocks in the Altyn Area, Xinjiang: Implications for the Tectonic Evolution of the Altyn Ocean
Table 1
Major (%) and trace element (ppm) data for the volcanic rocks in the northern Altyn Tagh region.
Rock type
Basalt
Rhyolite
Sample
KB-19
KB-23
KB-70
KB-58
KB-26
KB-33
KB-46
KB-76
KB-81
KB-82
KB-132
KB-138
SiO2
45.43
46.65
44.80
44.74
76.14
68.06
75.64
71.25
72.60
68.78
68.70
71.41
TiO2
1.79
3.75
1.57
2.98
0.19
0.41
0.26
0.20
0.32
0.65
0.52
0.23
Al2O3
17.42
14.46
15.48
16.93
12.79
11.59
10.31
9.60
14.60
13.79
12.73
14.57
TFe2O3
12.19
17.12
11.49
13.90
2.07
8.30
4.91
6.86
2.64
4.54
7.50
3.06
MnO
0.48
0.50
0.66
0.64
0.06
0.17
0.05
0.28
0.05
0.17
0.22
0.01
MgO
8.74
4.23
8.63
7.67
0.57
5.21
2.76
6.12
0.86
1.33
2.05
1.33
CaO
6.61
7.85
10.59
1.29
0.30
0.13
0.27
0.11
0.17
1.08
0.54
0.35
Na2O
3.10
2.80
1.77
3.11
5.79
1.28
0.19
0.05
2.46
4.27
0.17
3.99
K2O
0.80
0.18
1.44
0.67
1.27
1.30
2.11
1.22
3.80
4.08
4.56
2.81
P2O5
0.24
0.53
0.21
0.65
0.03
0.07
0.03
0.04
0.04
0.10
0.05
0.03
LOI
3.11
1.92
3.35
6.87
0.74
3.42
3.41
3.68
1.87
1.20
1.47
1.68
Total
96.80
98.07
96.64
92.57
99.21
96.52
96.54
95.72
97.54
98.79
97.03
97.79
A/CNK
0.97
0.76
0.65
2.07
1.12
3.09
3.33
6.03
1.72
1.03
2.06
1.42
A/NK
2.92
3.01
3.46
2.90
1.17
3.30
3.96
6.85
1.79
1.21
2.44
1.52
Na2O/K2O
3.89
15.56
1.23
4.68
4.56
0.98
0.09
0.04
0.65
1.05
0.04
1.42
Rb
31.00
4.95
60.50
46.70
38.70
71.40
101.00
23.80
143.00
117.00
115.00
92.70
Ba
1012.00
194.00
981.00
888.00
618.00
214.00
396.00
458.00
935.00
862.00
14744.00
635.00
Th
4.87
5.08
4.88
11.90
24.90
15.80
13.50
11.80
28.50
30.40
22.70
24.70
U
1.26
1.94
1.39
4.41
8.24
4.59
3.65
3.12
7.60
6.88
6.84
6.40
Nb
11.50
11.70
10.90
13.00
19.40
18.50
18.30
22.60
26.50
16.10
25.30
24.70
Ta
0.64
0.70
0.56
0.82
1.65
1.43
1.34
1.53
1.91
1.54
1.92
2.02
K
6607.48
1494.15
11953.23
5520.07
10542.08
10791.11
17514.80
10127.04
31543.24
33867.48
37851.89
23325.40
Cr
188.00
174.70
197.00
215.30
4.13
18.00
14.00
2.46
4.26
10.00
4.04
3.40
Ni
98.80
112.00
93.60
118.46
2.04
9.56
6.74
1.07
1.93
4.81
2.17
2.51
V
297.00
264.00
275.00
315.00
5.31
25.10
20.30
8.51
6.51
75.40
3.08
4.97
Co
50.20
35.30
53.90
67.90
0.43
2.57
1.28
0.61
1.24
9.66
0.85
1.70
La
24.70
25.60
27.60
43.70
61.20
51.00
45.20
47.20
56.90
46.00
59.70
66.80
Ce
50.10
61.50
56.70
83.60
107.00
110.00
85.10
79.80
93.10
86.20
102.00
131.00
Pb
36.10
44.80
44.70
283.00
8.48
4.06
5.99
18.40
7.30
94.50
91.00
6.18
Pr
6.22
10.00
7.93
12.90
15.30
13.20
10.30
9.02
13.80
10.20
15.60
15.50
Sr
370.00
394.00
460.00
144.00
107.00
32.10
26.60
22.60
75.80
80.70
322.00
104.00
Nd
26.70
48.50
36.50
57.00
58.10
52.40
39.00
33.00
50.40
39.70
66.50
61.40
P
1038.70
2308.71
929.59
2841.15
109.11
314.23
139.66
157.11
174.57
440.79
213.85
139.66
Sm
5.92
12.40
8.14
13.70
11.80
10.50
7.91
7.17
10.50
8.16
14.80
12.30
Zr
116.00
295.00
107.00
289.00
372.00
363.00
261.00
439.00
442.00
225.00
527.00
334.00
Hf
3.23
8.12
3.03
7.40
11.50
10.50
7.65
11.20
12.60
7.87
15.70
10.30
Eu
1.67
3.50
2.29
4.03
1.25
1.28
0.91
1.05
1.31
1.09
2.22
1.38
Ti
10728.35
22475.58
9409.78
17860.60
1144.76
2427.36
1582.28
1192.70
1905.93
3883.78
3086.65
1402.48
Gd
5.87
11.90
8.10
13.00
10.50
9.77
8.08
7.60
10.00
8.37
14.70
11.70
Tb
1.08
2.29
1.44
2.42
1.93
1.97
1.77
1.63
1.93
1.61
2.78
2.22
Dy
6.09
13.10
8.23
14.00
10.90
11.70
11.20
10.40
12.00
9.25
16.20
13.00
Y
33.20
69.70
39.00
74.50
53.90
60.40
62.30
61.10
73.70
56.40
85.00
69.40
Ho
1.21
2.62
1.50
2.65
2.20
2.38
2.29
2.17
2.51
1.88
3.22
2.56
Er
3.58
7.76
4.15
7.37
6.91
6.62
6.54
6.69
7.87
5.94
10.00
7.76
Tm
0.52
1.18
0.59
1.10
1.11
1.02
0.96
1.06
1.27
0.92
1.55
1.18
Yb
3.23
7.31
3.51
7.13
7.57
6.13
6.12
6.91
8.17
5.83
9.95
7.51
Lu
0.49
1.13
0.54
1.03
1.13
0.88
0.84
1.08
1.17
0.87
1.52
1.14
ΣREE
137.37
208.79
167.22
263.63
296.90
278.85
226.22
214.78
270.93
226.02
320.74
335.45
LREE
115.31
161.50
139.16
214.93
254.65
238.38
188.42
177.24
226.01
191.35
260.82
288.38
HREE
22.06
47.29
28.06
48.70
42.25
40.47
37.80
37.54
44.92
34.67
59.92
47.07
LREE/HREE
5.23
3.42
4.96
4.41
6.03
5.89
4.99
4.72
5.03
5.52
4.35
6.13
La/Nb
2.15
2.19
2.53
3.36
3.15
2.76
2.47
2.09
2.15
2.86
2.36
2.70
La/Ta
38.53
36.57
49.37
53.49
37.09
35.66
33.73
30.85
29.79
29.87
31.09
33.07
LaN/YbN
5.49
2.51
5.64
4.40
5.80
5.97
5.30
4.90
5.00
5.66
4.30
6.38
δEu
0.86
0.87
0.85
0.91
0.34
0.38
0.35
0.43
0.39
0.40
0.45
0.35
δCe
0.96
0.94
0.93
0.85
0.83
1.02
0.93
0.89
0.79
0.93
0.80
0.96
Note: major elements were obtained by X-ray fluorescence spectrometer (XRF) at the Analytical Laboratory of BRIUG, Beijing, using fused lithium-tetraborate glass pellets. The analytical precision as determined on the Chinese national standard GSR-3 was generally around 1–5%. Trace elements were analyzed using a PerkinElmer ELAN-DRC-e ICP-MS at the Analytical Laboratory of BRIUG, Beijing. The powdered samples (50 mg) were dissolved in high-pressure Teflon bombs using a HF+HNO3 mixture for 48 h, at ~195°C. Rh was used as an internal standard to monitor signal drift during counting. The international standards GBPG-1 and OU-6 and the Chinese national standard GSR-3 were used for analytical quality control, with the precision generally better than 5%.
