Abstract: This paper deals with the mineralogical and petrological features of eclogites from Mts. Hongtushan and Qinglongshan of the Donghai region, Jiangsu province. According to the experimental results of related rocks the genetic condition of eclogites can be estimated as T = 890° - 1275℃ and P = 17.25-24.75kb, and at the depth of 50-70km. From the petrochemical characters, the parent rock of eclogites can be considered as tholeiitic basalt. It can be assumed that the evolutionary process of eclogites in studied region started with metamorphism of tholeiitic basalt into basic granulite, and then, the basic granulite further turned into eclogite due to the dynamic process of progressive metamorphism. This process can be expressed by means of 0.61 hypersthene + plagio-clase (An = 61) = Omphacite (Jd = 39) + 0.61 kyanite + quartz. Finally, the eclogites a℃ompanied by the faulting intruded into the supracrustal migmatitic gneisses. In this process the temperature was decreasing from 1080℃±190℃ to 750℃±80℃, and the pressure from 21.0kb±3.75kb to 4.0kb±2.5kb. So that, the sequent retrogressive metamorphism of eclogites was caused by the dynamic effect of faulting. The conditional formula of this dynamic metamorphism can be approximately expressed as P(kb) = 0.0506T(C)-33.65.

摘要： 本文就红土山和青龙山榴辉岩的矿物、岩石组分和矿物共生组合特征,参照矿物、岩石实验数据和实验曲线,计算出该榴辉岩是在T=890°-1270℃,P=17.25-24.75Kb,相当于52—74公里深度的区域变质作用条件下形成。其原岩可能来源于拉斑玄武岩。榴辉岩在成岩后又遭受了剪切挤压的动力变质作用,使其经历了进变质和退变质作用。推测榴辉岩的成岩和迁移,所经历的条件是温度由1080℃±190℃降到750℃±80℃,压力由21.0Kb±3.75Kb 降到4.3Kb±2.5Kb,并被挤压到壳内混合岩化片麻岩系中,以大小不等的透镜体产出。动力变质的退变质作用,其温度、压力条件,本文计算的方程式为P(Kb)=0.0506T(℃)-33.65,为地震地质提供构造演变的条件和有关能量计算问题。