detrital zircon U-Pb dating

These data are taken from the Gasi section of the Tula Basin. The coordinates of the sample points are：GS016 (88.417736E 38.083125N)/ GS017 (88.417017E 38.085875N)/ GS022 (88.416350E 38.091683N). The samples used the New wave 193nm excimer Laser Ablation System (LA) and the Agilent 7700x inductively coupled Plasma Mass Spectrometer (ICP-MS) to achieve isotope analysis in the study area. The laser beam spot diameter was 36 mm and the laser pulse frequency was 10 Hz. The carrier gas of the denudative material is a plasma central flow (Ar+He) and a small amount of nitrogen is added. The zircon standard samples GJ-1 and 91500 released by the National Institute of Standard Technology and Wood of the United States were used as monitoring standards, and 91500 external standard calibration and GJ-1 standard determination were carried out for every 10 sample points measured by laser. Ensure that the instrument conditions of the sample and the standard sample are consistent during the determination process. For element concentration analysis, NIST610 and 29Si were used as external and internal standards respectively, and standard 91500 was used as external correction standard. The U-Pb isotope ratio and element content were calculated by glitter4.4 software. Finally, ICPMSDataCal program is used for analysis and ordinary lead correction processing. Isoplot software is used to calculate the zircon age and draw Concordia for analysis. The U-Pb age obtained is tested for inconsistency. Delete the zircon age data with harmony degree greater than 110 and the zircon age with harmony degree less than 90 from the statistics of zircon age. The error of the dating result is 1σ. For the U-Pb ages of the remaining effective zircons, if the age is less than 1000 Ma, the 206Pb / 238U ratio corrected by ordinary Pb is used, while if the age is greater than 1000 Ma, the 207Pb / 206Pb ratio corrected by common Pb is used as the age value.<br><br>