Note: Mines Office shifted to Ground Floor of Institute Menezes Braganza, Panaji-Goa
Loading

Mineral Resources of Goa - BAUXITE

 
 
 
  • The term bauxite is applied to the ores containing not less than 45-50% Al 2O 3 and not more than 20% Fe 2O 3 and 3-5% combined silica. It consists chiefly of hydrated aluminium oxides like gibbsite, bohemite, and diaspore. The impurities are silica, clay, silt, iron hydroxide and titania. It is formed in tropical and subtropical latitudes under good drainage conditions.
  • The Goa bauxite falls in the group of inter tropical bauxite deposits and are associated with laterites derived from metamorphic rocks.
  • The bauxite genesis occurs from silica, Alumina, and iron rich rocks; when silica is removed leading to enrichment of Al 2O 3 and Fe 2O 3 whereby silica values coming down from 40% to about 2-3%
  • The rock formations generally found in Goa include quartzite and quartz-sericite schist, quartz-chlorite schist, metavolcanics, conglomerates, limestone, phylites, banded ferruginous quatzite, granitic gneisses and various basic and ultrabasic intrusives, etc. belonging to Precambrian. Deccan Trap lava flows are seen in the upper reaches of the ghats along the North Eastern border of Goa All these rocks are covered by laterites which assume up to 15m thickness near the coast. The laterite have been classified (Gokul, 1974) as:
    • Pink ferruginous laterite
    • Limonitic laterite
    • Aluminous laterite
    • Bauxitic laterite
    The last one is pale pink to flesh red in colour whereas bauxite shows flesh red, cream and white colours.

The bauxite deposits can be grouped geographically into the following directiones as marked by GSI. following are the well-known areas of bauxite occurrences in Goa as marked by GSI.

  • North Goa depositswhich include the area of Chapora river, Mopa area, Pernem area, Morgim area, Dargalim, Ibrampur and Korgaon areas.
  • Central Goa deposits, which include Dabolim, Verna, Canua, Raia, Quessolim and Sancoale.
  • South Goa deposits which include the hily area of southwest Quepem, south of Chauri, Betul area and Polem -Loliem-Galgibaga area.
  • Minor scttered occurrences of aluminous laterite / lateritic bauxite occurrences of purely local incidence all over the lateritic terrain comprising Batim-Porvorim,Carmolim, Colvale, Taleigao-Bambolim and Calangute area. 

In addition to the above, laterites cappings are noticeable practically in the whole of Goa, and they offer a promising exploration target for locating bauxite deposits.