邯邢地区中生代角闪闪长岩中角闪石的成因矿物学研究

Genetic Mineralogy of Hornblende in the Mesozoic Hornblende Diorite in the Han-Xing Area

邯邢地区位于中生代太行山构造-岩浆活动带南缘、华北克拉通的中心,广泛发育中生代的高镁闪长岩,并伴生大量矽卡岩型铁矿。通过对邯邢地区角闪闪长岩中角闪石矿物进行成因矿物分析,应用角闪石温压计、氧逸度计和湿度计,计算了角闪闪长岩形成的物理化学条件,进而探讨了其形成与演化。研究表明,角闪闪长岩中的角闪石结晶温度为702.08℃~924.35℃,压力为36.55 MPa~266.21 MPa,氧逸度logfO2为-13.53~-9.78,平衡熔体含水为2.78%~5.73%;原始岩浆为幔源岩浆,并在演化过程中同化了大量的壳源物质;岩浆演化过程中曾经在10 km左右的深度的岩浆房中驻留,并发生过角闪石的结晶和分离。

The Han-Xing area is located in the southern margin of the Mesozoic Taihangshan tectonic-magmatic activity belt.The center of the North China Craton is widely developed with Mesozoic high-magnesia diorite and associated with a large number of skarn-type iron ore.The physicochemical conditions of the formation of hornblende are calculated by analyzing the genetic minerals of hornblende minerals in the hornblende diorite in the Han-Xing area,using the hornblende thermometer,oxygen fugameter and hygrometer,discussing its formation and evolution.Studies have shown that the hornblende crystallization temperature in the hornblende diorite is 702.08 ℃〜 924.35 ℃,the pressure is 36.55 MPa ~ 266.21 MPa,the fugacity logfO2 is-13.53 〜-9.78,the equilibrium melt water content is 2.78% ~ 5.73%.The original magma is a mantle-derived magma,and assimilated a large number of crust-derived materials during the evolution process;during the magma evolution process,it once resided in a magma chamber with a depth of about 10 km,and the crystallization and separation of hornblende occurred.