250px, View of one of the Mines in the Madre de Dios area Madre de Dios, located east the town of

Máfil Máfil (Mapudungun for ''embraced between rivers'') is a town and commune of the Valdivia Province, Los Ríos Region in southern Chile, about 30 km northeast of Valdivia. The main economic activities of Máfil are forestry, cattle farming, c ...

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

, is a

placer deposit In geology, a placer deposit or placer is an accumulation of valuable minerals formed by gravity separation from a specific source rock during sedimentary processes. The name is from the Spanish word ''placer'', meaning "alluvial sand". Placer min ...

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...

that has been mined several times since its discovery in 1556. The

bedrock In geology, bedrock is solid Rock (geology), rock that lies under loose material (regolith) within the crust (geology), crust of Earth or another terrestrial planet. Definition Bedrock is the solid rock that underlies looser surface mater ...

of the Madre de Dios area is made of

metamorphic Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causin ...

and

crystalline rock A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ...

s of

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ' ...

age all part of the Bahía Mansa Metamorphic Complex. These rocks are covered with thick layers of glacial

gravel Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone. Gravel is classifi ...

from the

Tertiary Tertiary ( ) is a widely used but obsolete term for the geologic period from 66 million to 2.6 million years ago. The period began with the demise of the non-avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start ...

. Gold eroded from the gravel have deposited in nearby streams, thus giving origin to the placer deposit. The deposit was discovered by Spaniards in 1556 but was not mined extensively until the late 19th century. From 1898 to 1936 a total of 2.6

tonne The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton ( United State ...

s of gold were produced. The deposits are currently being prospected by the Global Gold corporation.

References

Sources

Report on the Madre de Dios Placer Gold Project, Chile
Gold mines in Chile Mines in Los Ríos Region Surface mines in Chile 1556 establishments in the Spanish Empire {{mining-stub