Petrogenesis of Plio-Pleistocene volcanic rocks from the chagai arc ...

Table 2. A comparison of average trace element chemistry of Plio-Pleistocene calc-alkaline andesitesfrom the Chagai arc with some arc related andesites of the worldTrace Chagai Continental Margin ArcsOceanic Island ArcsElements& RatioArc Japan1Sunda2Zagros3Andes4Mariana5New Britain6Fiji Arc7Ti 3320 4080 4732 5691 4800 58.90 4140Rb 19.54 36 39 23 75 12.67 11 20Sr 563 294 466 619 648 378 384 490Ba 384.73 318 437 271 886 348 185 522V 121.69 172 153.8 125 186 340 172Cr 79.77 67.5 19 104 48 23.67 34 39Co 21.88 21 18 19 31.33 16Ni 17.23 35.5 10.8 39 10.33 23 9Zr 97.12 123 84.80 195 70.6 34 114Y 13.92 19 21.6 12 24 12 18Nb 4.12 3 2.8 1.1 0.9 2Hf 1.58 3.8 5.46 2.3Ta 0.51 0.14 Th 2.06 3.4 1.8U 1.58 1.4 0.75Sc 19.12 18.6 13 39Cu 45.3 40 103 36La 12.73 9.7 12.85 15 38 30.6 3 11Ce 24.17 23 27.96 34.2 66.8 25.3 10 27Nd 11.30 12 16.07 23.33 Sm 2.28 3.3 3.45 2.75 20.37 Eu 0.82 0.90 1.12 1.01 17.1 Gd 2.63 18.03 Er 1.11 12.9 Yb 1.28 2.2 1.50 1.48 1.94 11.2 Ti/V 28.50 23.72 30.77 45.60 25.81 10.06 24.07Zr/Y 6.98 6.47 3.93 15.98 2.94 2.83 6.33Ti/Zr 34.85 33.17 55.80 29.23 67.99 100.59 36.32Zr/Nb 23.93 4140 30.29 64.18 37.78 57La/Yb 10.16 4.40 8.57 10.14 19.49 2.73 Ce/Yb 19.42 10.45 18.64 23.11 34.43 2.26 The values in column 1 are after Govindaraju, (1989), 2 after Wheller et al. (1987), 3 after Dupuy andDostal (1978), 4 afterEwart (1982), 5 after Woodhead (1988), 6 and 7 after Gill (1981). All the data in ppm.20