定量估计造山带地壳厚度的岩石地球化学方法：综述与实例

he quantitative methods used for estimating the (paleo-) crustal thickness from geochemical data inclThe Geochemical Methods for Quantitative Estimation of the Crustal Thickness of Orogenic Belt: Overview and Case Studiesudes the K2O content of the calc-alkaline suite (K60, K55, K57.5 and K2O/Na2O), the content of Na2O and CaO (Na6.0 and Ca6.0) and the Ce/Y ratio of the arc basaltic rocks, the Sr/Y and (La/Yb)n ratios of the calc-alkaline suite, etc. The quantitative formulas are reliable to infer the crustal thickness of the subduction orogenic belt, which thickness are in range of 20 to 45 km. The Sm/Yb and Dy/Yb ratios of the intermediate-acidic rocks can constrain the thick crust more than 50 km. The proper application of the quantitative and semi-quantitative proxy to estimating the crustal thickness of orogenic belt requires that, obeying the conditions and scopes of the method, gathering a dataset for analysis as large as possible, and doing data screen and outlier elimination. For the case of Gangdese in south Tibet, it concludes that the (La/Yb)n ratio can be used to estimate the thickness of crustal thickness in the post-collisional environment. The remarkable jump of Sr/Y and (La/Yb)n ratios in the intermediate magmatic rocks since 40 Ma was due to the crust thickening caused by the India-Asia collision. The crustal thickness of Yidun island arc in Sanjiang area was 60 km in Triassic. The crustal thickness of Early Cretaceous magmatic arc occurred in the Changle-Nan'ao Tectonic Zone, Fujian was 42 km. The crustal thickness of western Liaoning Province was 50 ~ 65 km in Mid-Jurassic to Early Cretaceous period.