Base metal mineralization at the Baal Gammon and Isabel deposits of the Herberton Mineral Field (HMF) is hosted in metamorphosed greywacke beds in the Hodgkinson Formation, which were intruded by granite, porphyry dykes and overlain by volcanic rocks of the Kennedy Igneous Association during the Carboniferous and Permian. The tin mineralization at the Baal Gammon deposit is hosted by a silicified, chlorite-altered, quartz-feldspar porphyry (UNA Porphyry). The tin mineralization at the Isabel deposit is in polymetallic veins hosting disseminated cassiterite. Polymetallic sulfides (Cu-Zn) and indium (In) mineralization at both deposits overprint the tin mineralization. Chalcopyrite, sphalerite, and stannite host indium in the polymetallic sulfide assemblage at both deposits. Based on overprinting relationships, the timing of tin mineralization is related to the magmatic activity at ca. 320 Ma, whereas the sulfide and indium mineralization are most likely associated with the emplacement of porphyry dykes at ca. 290 Ma. The overall magmatic activity in the HMF spreads between ca. 365 and 280 Ma, with peaks at ca. 337, 322, 305, and 285 Ma. The change from tin mineralization at ca. 320 Ma to sulfide and indium mineralization at ca. 290 Ma indicates a transition from a compressive to an extensional tectonic regime.

Herberton Mineral Field (HMF) 的 Baal Gammon 和 Isabel 矿床的贱金属矿化位于 Hodgkinson 组的变质灰岩层中，这些岩层在石炭纪期间被花岗岩、斑岩岩脉侵入并被肯尼迪火成岩协会的火山岩覆盖和二叠纪。Baal Gammon 矿床的锡矿化由硅化、绿泥石蚀变的石英长石斑岩（UNA Porphyry）组成。Isabel 矿床的锡矿化位于多金属矿脉中，分布着浸染的锡石。两个矿床的多金属硫化物 (Cu-Zn) 和铟 (In) 矿化覆盖了锡矿化。黄铜矿、闪锌矿和锡矿在两个矿床的多金属硫化物组合中都含有铟。基于套印关系，锡矿化的时间与大约 ca 的岩浆活动有关。320 Ma，而硫化物和铟矿化最有可能与斑岩岩脉的侵位有关。290 毫安。HMF 中的整体岩浆活动分布在 ca 之间。365 和 280 Ma，峰值在 ca。337、322、305 和 285 毫安。大约锡矿化的变化。约 320 Ma 到硫化物和铟矿化。290 Ma 表明从压缩到伸展构造状态的转变。约 320 Ma 到硫化物和铟矿化。290 Ma 表明从压缩到伸展构造状态的转变。约 320 Ma 到硫化物和铟矿化。290 Ma 表明从压缩到伸展构造状态的转变。