Table 2. 

Lutetium–hafnium isotope data

Zoning176Lu/177HffLu/Hf*176Hf/177Hf (today)2σ (× 10−6)εHf (today)Age† (Ma)176Hf/177Hf (initial)εHf (initial)TDM (Ma)TDM* (Ma)
Cochrane unit
CA-00-30:01Metamorphic0.000364−0.9890.28208321−24.413980.282073+6.3 ± 0.715981659
CA-00-30:02Magmatic0.000825−0.9750.28204120−25.910850.282024−2.5 ± 0.716761848
CA-00-30:18Magmatic0.00100−0.9700.28248223−10.34290.282474−1.1 ± 0.810621243
CA-00-30:22Metamorphic0.0000228−0.9990.28222314−19.45260.282222−7.9 ± 0.513921668
CA-00-30:24magmatic0.00112−0.9660.28056125−78.234950.280486−1.8 ± 0.937283794
CA-00-30:26Metamorphic0.000907−0.9730.28233719−15.411020.282318+8.3 ± 0.712641311
CA-00-30:31Metamorphic0.000701−0.9790.28119017−55.926720.281154+2.8 ± 0.628402890
CA-00-30:33Magmatic0.000376−0.9890.28108221−59.826040.281063−2.0 ± 0.729613072
CA-00-30:36Metamorphic0.000373−0.9890.28120723−55.324390.281190−1.3 ± 0.827932902
CA-00-30:37Magmatic0.00160−0.9520.28241618−12.64840.282401−2.5 ± 0.611741357
CA-00-30:42Magmatic0.000700−0.9790.28194318−29.312110.281927−3.1 ± 0.618061983
CA-00-30:49Metamorphic0.000529−0.9840.28179631−34.512450.281784−7.4 ± 1.120002227
CA-00-30:53Metamorphic0.000678−0.9800.28197520−28.216300.281954+7.3 ± 0.717611800
CA-00-30:56Magmatic0.000987−0.9700.28233414−15.59890.282315+5.7 ± 0.512711352
CA-00-30:57Metamorphic0.0000910−0.9970.28203215−26.25690.282032−13.7 ± 0.516551999
CA-00-30:61Magmatic0.00179−0.9460.28224919−18.512210.282208+7.1 ± 0.714211473
CA-00-30:64Magmatic0.000750−0.9770.28242918−12.15780.282421+0.3 ± 0.611291292
Bahía de la Lancha Formation
CA-01-06:22Magmatic0.000508−0.9850.28205921−25.211130.282048−1.0 ± 0.716371796
CA-01-06:25Metamorphic0.0000887−0.9970.28239914−13.26290.282397+0.6 ± 0.511521318
CA-01-06:32Magmatic0.000542−0.9840.28246126−11.010560.282450+12.0 ± 0.910781085
CA-01-06:45Mix0.002620.9210.282643194.53230.282628+2.0 ± 0.7870996
CA-01-06:62Magmatic0.00104−0.9690.28223220−19.19270.282214+0.7 ± 0.714161554
CA-01-06:63Mix0.0002280.9930.2815191744.37110.28151628.8 ± 0.623622871
CA-01-06:66Magmatic0.000827−0.9750.28233519−15.512520.282316+11.6 ± 0.712641267
  • TDM=ln[(176Hf/177Hfsample,today176Hf/177HfDM,today)/(176Lu/177Hfsample,today176Lu/177HfDM,today)+1]/λ and Embedded Image, where T represents the zircon growth age. 176Lu/177Hfcrust,T was calculated assuming 176Lu/177Hfcrust,today=0.0093, average of granitoid data from Vervoort & Patchett (1996).

  • *Deviation of 176Lu/177Hf from CHUR: fLu/Hf=(176Lu/177Hfsample,today/176Lu/177HfCHUR,today)−1.

  • †U–Pb zircon ages

  • ‡Grain with several growth phases; corresponding values were not used further.