The Choco province is located at West of Colombia, in Pacific Ocean Coast. The area of interest is located approximately 400km NW of Bogota, capital of Colombia. The Choco province is located at West of Colombia, in Pacific Ocean Coast. The area of interest is located approximately 400km NW of Bogota, capital of Colombia. These province its historically recognized as producer of precious metals. These province its historically recognized as producer of precious metals. The capital of the province is Quibdo, the province introduced an incipient road infrastructure, being the Atrato and San Juan rivers major routes mobilization. The capital of the province is Quibdo, the province introduced an incipient road infrastructure, being the Atrato and San Juan rivers major routes mobilization. We provide two applications for mining licences, located in the town of Istmina, one of them with roads to facilitate their access and is less than 15 km from the downtown area of this municipality. We provide two applications for mining licences, located in the town of Istmina, one of them with roads to facilitate their access and is less than 15 km from the downtown area of this municipality.

Chocó is an area of oceanic crust placed in western Colombia. It is part of an islands arc which continues along Panamá to Northwest and to the South along the Pacific shelf to Ecuador territory. The parts of the islands arc in Chocó are well defined, the subduction zone is along the Baudó coast, where the Cabo Corrientes and Bahia Solano peninsulas are wedges of the subducting plate, East of them there is a wide fault zone, known as Utria fault which looks as a melange zone. More to the East it is the Baudó range, it represents the outer arc, next to the East there is the San Juan- Atrato depression, it is the inner basin, farther to the East it is the inner or magmatic arc, represented by a belt of Cenozoic intrusions and volcanic buildings. East of it, there is the Western Cordillera, formerly a transarc basin, now folded by effect of the tangential shock between the islands arc and the sialic crust, represented by the Central Cordillera.

The basalts of the obducting plate are typical tholeiites, composed of plagioclase and clinopyroxene. They are overlain by cretaceous marine sedimentites of deep sea environment, principally, turbidites and cherts. The basalts of the subducting plate present more variation in their compositions; in the peninsulas, where it is possible to observe the subducting plate, it is possible to find olivine basalts and picrites. The magmatism of the inner arc is very low in alkalies, the composition of the volcanites varies between basalt and dacite, the intrusive rocks are predominantly quartzdiorites with local variations to diorite and gabbro. The sequence of sedimentary rocks in the intermediate basin comprehends Eocene detritic and volcano-sedimentary deposits, Oligocene pelitic, marly and calcareous deposits, Miocene sandstones and mudstones (Photos 1, 2, and 3) with interbedded conglomerates and more recent coastal sands and gravels (Photo 4).

Resting on them there are recent volcanic deposits (Photo 5), principally pyroclastics which develop white or clear gray soils. Those deposits are very thick at the center of Atrato-San Juan depression. The tectonics of the island arc are characterized by a system of strike slip faults N-S direction, specially, in the intermediate basin, the inner arc and the Western Cordillera. Northwest of Istmina there is a system of NE-SW faults whose relative displacement is not clearly stablished.

It is not easy to identify the composition of the volcanic rocks, they weather to clear colored clays, then it is a low iron content rock, at spite of the abundance of quartz and different type of silica in the breccias, it looks that the originary rock must be subsilicic, because the tuffs and sands look quartz free. Possibly it can be spilitic or lamprophyric composition. The volcanic foci are not known, but clearly it is a different and younger magmatic event than that of the inner arc.

Photo 15: Mining pit near Condoto village.

Photo 16: Sluices in very small scale mining.

Photo 17: Scavator working between Novita and Condoto village.

Photos 18 to 21: Paned gold and platinum.