There are a multitude of mineral ores used to produce industrial metals, which can be organized into four major groups with similar geological histories. Iron (Fe) and manganese (Mn) are essential components to steel and, as such, are in constant demand by manufacturers and the construction industries. Ferro-manganese ores are found within the ancient sedimentary rocks that were created when the first photosynthetic organisms were transforming the Earth’s atmosphere during the Archean Eon as oxygen reacted with dissolved iron in primeval oceans to create ferrous oxides, hematite and magnetite (FeO, Fe2O3, Fe3O4). These ancient sedimentary rocks were uplifted during the ancient orogenies that moulded the Amazon Craton and occur in three separate landscapes of the Eastern Amazon: the Carajás province in Eastern Pará, a similar area across the Amazon River in Amapá and the Imataca formation just south of the Orinoco River in Venezuela. Base metals, particularly copper (Cu), zinc (Zn), molybdenum (Mo), nickel (Ni) and lead (Pb), are used by a wide range of industries, but are particularly important for electrical devices and industrial alloys. These industrial metals tend to occur in polymetallic ores associated with magma that originated deep within the Earth’s crust; ore bodies are found along the margins of magmatic intrusion or within fissures in the surrounding matrix rock. On the Amazon Craton, intrusions are associated with ancient orographic events and their idiosyncratic distribution reflects the complex geological evolution of the Precambrian Era. In the Andes, intrusions exist as ‘porphyries’ that are linked to relatively recent…This article was originally published on Mongabay
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