Carta de Depósitos Minerais da Região Norte de Portugal à escala 1:200 000
The Northern Region Mineral Deposit Charter includes a total of 800 deposits - metallic minerals, non-metallic minerals and granular industrial rocks - mostly from the Varisca orogeny. This is the sector in the country with the largest number and variety of known types of mineralization. These deposits range from simple occurrences to large deposits. In the group of metallic minerals are represented mineralizations of: antimony, arsenic, beryllium, bismuth, lead, copper, chromium, tin, iron, lithium, manganese, molybdenum, nickel, gold, silver, tantalum/niobium, titanium, tungsten (wolframite), tungsten (scheelite), uranium and zinc. The group of non-metallic minerals and concessible industrial rocks includes: barite, kaolin, kaoliniferous sands, coals (metamorphized), talc, asbestos (asbestos), graphite, fluoride (fluorite), quartz and feldspar.
In terms of representation, several elements can be observed in each mineral deposit: in addition to the name of the mineral deposit and the number assigned, each substance appears represented by a color; in terms of size, in addition to the occurrences, the deposits are classified into small, medium and large, with symbols of appropriate dimensions; in terms of morphology, the mineral deposits appear classified into several types: pocket, breccia, chimney, dissemination, stratiform, stratum, philonian, irregular, lenticular, mass, other, stockwork and shear zone, represented by a proper symbol and include the respective direction when known; at the level of genetic characterization, the classification is subdivided into 2 large groups: metallic mineral deposits; non-metallic mineral deposits and industrial rock deposits, for a total of two dozen genetic base types.
Porto doesn't have any deposit mineral registry on its boundaries, However there is deposit boundaries in its neighbouring municipalities, in particular Valongo Municipality.