据报,一些地质学家曾讨论了花岗岩岩浆、特别是那些与潜没带伴生的岩浆的生成问题。板块接合处的金属矿床带表明,金属来源于潜没带,而上升的花岗岩岩浆,也许仅仅是起了载体的作用。金属可能是以络合卤化物离子的形式运移的,对锡来说,从破碎的磷灰石中释放出来的氟化物可能是载体离子。布朗利博士强调指出了锰结核作为潜没带下许多金属的载体的重要性,但它不是锡和钨的载体。在康沃尔,矿化区内的节理上覆盖着相当多的锰,据此,他提出了一个问题:“在这些地区,锰是否产生了对找矿有用的宽阔的晕?” It has been reported that some geologists have discussed the formation of granite magmas, especially those associated with subduction zones. The metallogenic belt at the tectonic plate junction shows that the metal comes from the subduction zone, while the ascending granite magma may only act as a carrier. The metal may have migrated as a complex halide ion, and for tin, the fluoride released from the fractured apatite may be carrier ions. Dr. Brownlee emphasized the importance of manganese nodules as a carrier for many metals under the latent belt, but it is not a carrier for tin and tungsten. In Cornwall, the joints in the mineralized area are covered with a considerable amount of manganese, and as a result he asked the question: “In these areas, does manganese produce a wide halo that is useful for prospecting?”