滇西北宁蒗地区喜山期斑岩带形成的构造机制

宁蒗地区地处扬子准地台西缘与松潘-甘孜褶皱系的接合部位．其东为南北向的康滇地轴．西为近南北向的三江构造带。这种特定的区域构造背景决定着本区基本的菱形构造格局。区内北东向金棉-木里断裂将本区划为两个不同的建造-构造区：宁蒗西北区和宁蒗东南区。宁蒗东南区受四条北东向与北西向深断裂为界的宁南菱形构造控制，形成了叙方对称型的宁南反凸双孤联合构造。该宁南反凸双孤联会构造东弧带追踪基底南北向构造所形成的包都-波罗弧形断裂构造，控制了本区喜山期斑岩带的形成和分布。区内斑岩群（体）主要分布于该主干控岩断裂带与其它多方向构造的复合系统中。通过模拟实验，进步验证了区内斑岩带的控岩造机制。

THE STRUCTURAL MECHANISM ABOUT THE FORMATION OF PORPHYRY BELT DURING HIMALAYAN PERIOD IN NINGLANG AREA OF NORTHWEST YUNNAN PROVINCE

Ningbog area lies on the juncture of Yangtze Platform and Songpan-Ganzi Fold System,There are north-southern Kandbo earth's axis in the east and nearly north-squthern Sanjiang structural belt in the west. The special regional tectonic surroundings lead to essential rhombohedtal structure framework in Ninglang area. The northeastern fault of Jinmian-Muli divides Ninglang area into two formation-structure districts: northwest and southeast of Ninglang The southeret of Ninglang is controlled by Ningnan rhombohedral structure and develops Ningnan bogeir jUnction structure. The formation and distribution of porphrty belt during Himalayan period are controlled by Baodu-Boluo fault formed through Ningnan bogen junction structure tracking north-southern structure on basement. The porphyry bpdies distribute in the compound system of main structural belt and other associated structure. The structural mechanism controlling rock on porphyry belt is tested and verified through model experdrient.