Table 6.

LA-ICP-MS U–Pb isotope data and dates for concordant analyses of zircon in sample 55-D

PointPositionTh (ppm)U (ppm)Th/U207Pb/235U206Pb/238Urho207Pb/235U206Pb/238U
Ratio(±1σ)Ratio(±1σ)Date (Ma)(±1σ)Date (Ma)(±1σ)
55-D_38R12.62364.60.0010.0370.00200.0050.00010.2237.22.032.60.4
55-D_07R12.3883.70.0030.0350.00290.0050.00010.2035.32.932.40.5
55-D_04R14.11878.10.0020.0340.00160.0050.00010.2433.61.631.50.4
55-D_09R11.8626.20.0030.0470.00440.0050.00010.2346.44.231.10.7
55-D_40R16.91550.20.0050.0330.00210.0050.00010.1933.02.031.00.4
55-D_01R118.12038.70.0090.0320.00170.0050.00010.2432.31.730.40.4
55-D_18R114.11937.40.0080.0300.00180.0050.00010.2129.91.829.80.4
55-D_19R116.72538.50.0070.0290.00160.0040.00010.2229.11.528.60.3
55-D_14R18.61514.10.0060.0280.00200.0040.00010.1928.51.928.40.4
55-D_32R119.03203.50.0060.0310.00140.0040.00000.2231.31.428.30.3
55-D_34R117.42635.10.0070.0280.00130.0040.00010.2527.61.328.00.3
55-D_28R126.86528.10.0040.0290.00090.0040.00000.2728.80.927.70.2
55-D_24R134.24587.90.0080.0300.00120.0040.00000.2729.71.127.70.3
55-D_22R118.42741.10.0070.0280.00140.0040.00010.2727.71.427.60.4
55-D_25R124.04067.40.0060.0280.00100.0040.00000.2828.11.026.70.3
55-D_27R129.46088.70.0050.0260.00140.0040.00000.1826.21.325.20.2
55-D_30R226.2921.10.0300.0240.00260.0030.00010.1624.02.621.80.4
55-D_11R229.71382.30.0220.0220.00240.0030.00010.2022.52.421.40.5
55-D_12R240.81347.20.0310.0220.00180.0030.00010.2121.91.820.80.4
55-D_05R282.06024.60.0140.0200.00080.0030.00000.2720.60.819.70.2
55-D_33R241.91478.00.0290.0230.00160.0030.00000.2323.11.619.30.3
55-D_08R247.62131.70.0230.0160.00190.0030.00010.2215.71.919.10.5
55-D_06R260.75108.50.0120.0200.00090.0030.00000.2120.00.819.00.2
55-D_35R247.02627.50.0190.0180.00110.0030.00000.1918.31.118.80.2
55-D_03R280.01480.40.0560.0180.00170.0030.00000.2018.51.716.80.3
55-D_37R2103.43152.10.0340.0160.00120.0020.00000.1816.51.215.20.2
55-D_36R236.8624.70.0610.0200.00300.0020.00010.1920.12.915.10.4
55-D_31R273.84320.20.0180.0130.00070.0020.00000.2012.80.713.10.2