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山东省日照市胡家林石榴橄辉岩产于苏鲁超高压变质带中, 其中的锆石主要为柱状和粒状(长/宽 = 1︰1.3 ~ 2.5), 晶型较好. 阴极发光(CL)和背散射(BSE)图像显示具岩浆成因的成分环带, Th/U比为0.99~2.81, 为岩浆成因的锆石特征. 14个点的锆石 SHRIMP U-Pb年龄分析给出206Pb/238U年龄范围为207~223 Ma, 加权平均值为 216 3 Ma, 与大别-苏鲁超高压变质岩片折返过程中角闪岩相退变质的时代一致. 石榴橄辉岩在随超高压变质岩片折返过程中被携带到地壳环境, 受到来自超高压岩片内部释放的流体交代, 锆石U-Pb年龄记录了交代所形成的熔体结晶时代. 因此, 深俯冲大陆板块折返过程中的流体释放可能是其中锆石生长的重要流体来源.
The Hujialin pomegranate permafrost in Rizhao City, Shandong Province, is produced in the UHP metamorphic belt of the Sulu, where the zircons are mainly columnar and granular (length / width = 1: 1.3 ~ 2.5) Scattering (BSE) images show the zoning of facies with magmatic origin, with a Th / U ratio of 0.99-2.81, which is a zircon characteristic of magmatic origin.The zircon SHRIMP U-Pb age analysis of 14 points gives the 206Pb / 238U age range From 207 to 223 Ma with a weighted mean value of 216 3 Ma, consistent with the age of amphibolite facies metamorphism during the reenforcement of the Dabie-Sulu ultrahigh-pressure metamorphic rock.The pomegranate dolomite was carried during the reenforcement with the UHP metamorphic rocks To the crustal environment and was interpreted by fluids released from the interior of the UHP rocks and the zircon U-Pb age recorded the melt crystallization age of the metasomatism.5 Therefore, the fluid release during the reentry of the deep-subducting continental plate may be one in which zircon growth An important source of fluid.