兰坪—思茅盆地铜矿床区域控矿因素

THE REGIONAL ORE-CONTROLLING FACTORS OF COPPER DEPOSITS IN THE LANPING-SIMAO BASIN

本文探讨了深部构造、地热场和成矿元素分区对兰坪—思茅盆地中铜矿床区域分布的控制。莫霍面斜坡和隆－坳过渡带上地幔向上蠕动，基底抬升，利于热卤水循环上升和改造成矿；热流值高的区带，热动力强，改造型矿床发育。盆地基底岩系和中、新生界中的成矿元素存在分区性，西缘北段和中部相对富Ｃｕ、Ｓｂ、Ａｓ等元素，可作为今后的找矿靶区。

The regional distribution of copper deposits under the control of deep seated structure, terrestrial heat field and oreforming elemental division are discussed. It is indicated that the Moho slope and transition (uplift depression), where uneven mantal heat current resulted in upper mantal creep upwards and basement elevation, were favourable areas for hot brine circulating upwards and mineralization. In the region with high value of mantal heat current qm, crustal heat current qc, and average surface heat current qs,the thermal-dynamic action and reformation were very intensive. The reformed copper deposits or ore spots are distributed extensively. The distribution of ore-forming elements in basement rocks and the mesozoic-Cenozoic red-beds shows division characteristics: Cu, Sb, As et al. are relatively enriched in the northern part of west margin and the centre of the basin.From above, some ore-searching orientation and prospecting targets have been proposed.