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腾冲地块芒棒乡新生代新近纪芒棒组火山岩的研究,发现粗面安山岩中含有较多麻粒岩包体,主要类型为长英质麻粒岩和二辉麻粒岩,直径一般为3~5cm,略具定向排列构造,粒状变晶结构特征.长英质麻粒岩包体平衡温度和压力为:869~969℃,0.94~1.00GPa,二辉麻粒岩包体平衡温度为:841~972℃,均显示为高温麻粒岩相变质;寄主岩粗面安山岩中斑晶结晶估算的温度和压力为:1 008~1 059℃,1.26~1.33GPa,表明它们形成和起源于下地壳到上地幔顶部之间.二辉麻粒岩包体电子背散射衍射(EBSD)显微组构分析表明,斜方辉石(紫苏辉石)和单斜辉石(普通辉石)均具有明显晶格优选方位(LPO),斜方辉石和单斜辉石主滑移系分别为:(010)[001]和(100)[001]、(010)[001],变形机制为位错蠕变,说明麻粒岩包体经历了高温塑性变形变质作用.新生代新近纪火山岩中高温麻粒岩的发现和研究表明,腾冲新生代岩浆活动可能与印度板块和腾冲地块俯冲-碰撞造山后的伸展垮塌-拆沉和板片断离,以及随后的上地幔物质上涌减压熔融产生玄武质岩浆底侵,导致的下地壳发生高温变质及火山岩浆作用有密切关系.
The study of the Cenozoic Manshangpa volcanic rocks in the Moguang area of the Tengchong block shows that there are many granulite inclusions in the coarse andesite, the main types are the felsic granulites and diperfluses, and their diameters are generally 3 ~ 5cm, with a slight directional arrangement and granulite structure.The equilibrium temperature and pressure of the Changling granulite inclusions are 869 ~ 969 ℃ and 0.94 ~ 1.00GPa, and the equilibrium temperature of the two-pyroclastics granule is : 841 ~ 972 ℃, showing high-temperature granulite facies metamorphism. The estimated temperature and pressure of the porphyritic crystals in the host-facies andesite range from 1 008 ℃ to 1 059 ℃ and 1.26 ~ 1.33GPa, indicating that they formed and originated from The lower crust to the top of the upper mantle.EBSD microscopy analysis of the inclusions of Erhui granulite inclusions shows that the orthopyroxene (peridotite) and clinopyroxene (pyroxene) (001) and (100) [001] and (010) [001], respectively. The deformation mechanism is Dislocation creep, indicating that the granulite inclusions experienced high temperature plastic deformation and metamorphism.The Cenozoic volcanic rocks in the Cenozoic high temperature granulite discovery and research shows that the Tengchong Cenozoic magmatic activity It can subduct with the Indian plate and the Tengchong block - collapsing and collapsing after collisional orogeny - detachment and plate detachment, and subsequent upwelling and downwelling melting of the upper mantle to produce basaltic magma underplating, resulting in high temperature metamorphism of the lower crust and high temperature metamorphism Volcanic magmatism is closely related.