Redefinition of the "Dakendaban Group" on the northern margin of the Qaidam basin

The strata on the northern margin of the Qaidam basin were originally assigned to the Paleopro-terozoic"Dakendaban Group".It,exposed quite extensively,includes not only supracrustal rocks of dif-fering metamorphic grades but also metamorphosed plutons of utterly different ages.Recent study indicates that it comprises at least four suites of rock associations.The first suite is called the Delingha complex,which is the oldest,being the early Paleoproterozoic product.The second one is the redefined so-called Dakendaban Group-complex,which is a suite of medium-to high-grade metamorphic supracrustal rocks dominated by parametamorphic rocks and is inferred to be of late Paleoproterozoic to Mesoproterozoic age.The third suite is granite gneiss,formed mainly in the early Neoproterozoic and not belonging to sedimen-tary strata,in which there appear large quantities of eclogite inclusions.The last suite is eclogites,which occur as separate small inclusions or large relics in the Neoproterozoic granite gneiss and also are associated with marble,quartzite and garnet-bearing schist;these eclogites and their associated supracrustal rocks com-bine to form the Iqe River or Shaliu River Group-complex.