Adao

Past Producer in Minas Gerais, Brazil with commodity Gold

Sections on this page

Identification information
Geographic coordinates
Site location context
Geographic areas
Commodities
Materials information
Nearby scientific data
Ore body information
Economic information about the deposit and operations
Links to other databases
Bibliographic references
General comments
Reporter information

Geologic information

Identification information

Deposit ID	10064789
MRDS ID	TC39285
Record type	Site
Current site name	Adao

Geographic coordinates

Geographic coordinates:	-43.67701, -19.86443 (WGS84)
Location accuracy	1000(meters)
Relative position	ABOUT 1 KM NW OF JOSE BRANDAO

Site location context

Political divisions (FIPS codes)

Minas Gerais(province)

Brazil(country)

South America(continent)

Land(continent)

Geographic areas

Country	State
Brazil	Minas Gerais

Comments on the location information

LATITUDE/LONGITUDE MIDPOINT OF A LINE OF LODE DEPOSITS ABOUT 15 KM LONG FROM NORTH TO SOUTH INCLUDING HILLS PROSPECT, AN UNIDENTIFIED PROPERTY, CAMPBELL AND PARTY, AND FOUR OTHER UNIDENTIFIED PROPERTIES; IMPORTANT GIBSONVALE ALLUVIAL TIN DEPOSIT AT LAT 33-40 S, LONG 146-41E.
ON MORRO ADAO WEST FLANK, USED ONE OF ADITS FOR LOCATION NEAR TRAIL

Commodities

Commodity	Importance
Gold	Primary

Comments on the commodity information

CASSITERITE IS SUB-ANGULAR TO ROUNDED WITH 90 PERCENT PASSING 6 MESH AND RETAINED ON 100 MESH.

Materials information

Materials	Type of material
Gold	Ore

Nearby scientific data

(1)	-43.67701, -19.86443	ListMap

Economic information

Ore body information

Name ADAO

Dip }

Name	ADAO
Dip	}

Comments on the geologic information

SEDIMENTS MAKING UP THE OVERBURDEN HAS COMPLETELY FILLED THE ANCIENT VALLEY; THE UPPERMOST PART ARE VERY POORLY SORTED AND HAS A DISTINCTIVELY DIFFERENT CLAY TO THAT SEEN BELOW, SOME OF THIS MATERIAL MAY BE AEOLIAN; BELOW THIS IS 2 TO 15 M THICK CREAMY WHITE SANDLY CLAY; BELOW THIS IS A 3 TO 20 M THICK SAND BED EXCLUSIVELY QUARTZ VARING FROM +80 MESH TO -20 MESH IN SIZE WITH MINOR AND UNCEMENTED CLAY BUT SOME SAND IS CEMENTED WITH HORIZONTALLY ORIENTED SILICA LAYERS LIKELY ASSOCIATED WITH PALEO WATER TABLES; IRREGULAR PATCHES OF SILICA BETWEEN 5 CM AND 5 M THICK IN THE SAND BED WHICH RESTS DIRECTLY ON THE TIN GRAVELS. CHANNEL HOSTING ORE DEVELOPED DURING THE LATE OLIGOCENE ; BEDROCK SOURCE OF TIN ARE QUARTZ VEINS WITH CASSITERITE, MINOR ASSOCIATED SILVER, WOLFRAMITE AND GOLD AND ABUNDANT ARSENOPYRITE, PYRITE, AND CHALCOPHYRITE IN, AND ALONG BOTH SIDES OF, A 15 KM LONG CONTACT ZONE WITH LATE ORDOVICIAN METASEDIMENTS METAMORPHOSED TO LOWER GREENSCHIST FACIES ON ONE SIDE AND GRANITES
(MIDDLE SILURIAN AGED (403 MY) KIKOIRA GRANITE) ON THE OTHER; SOME ROCKS NEAR CONTACT CONTAIN ANDALUSITE AND SMALL, TOURMALINE-BEARING GREISEN; FINE-GRAINED DISSEMINATED CASSITERITE NOTED IN GRANITE DIKES.

Economic information about the deposit and operations

Development status	Past Producer
Commodity type	Metallic
Deposit size	Small
Significant	No

Comments on the production information

SN CONCENTRATE (1) AND ORE (1) = UNIDENTIFIED SMALL-SCALE OPERATORS IN DRIFT MINES, MOST PRODUCTION IN 1939-1945; ORE (2) AND SN CONCENTRATE (2) = METALS EXPLORATION N.L., SN CONCENTRATION HAS AVERAGE OF 75.4 PERCENT SN METAL, THIS GIVES A PRODUCTION GRADE OF 2.67 KG SN/CM.

Comments on the reserve resource information

ORE (2) = METALS EXPLORATION N.L., GIVEN THE SN CONCENTRATE HAS AN AVERAGE OF 70 PERCENT SN METAL, THE RESERVE GRADE WOULD BE 2.16 KG SN/CM.

Comments on the workings information

SHAFTS WERE USED TO EXTRACT RICHEST SN ORE FROM BASAL GRAVELS; DEPOSIT SUBSEQUENTLY WORKED BY OPEN PIT.
ABOUT 10 ADITS ON W SIDE OF MORRO ADAO

Comments on development

LODE DEPOSIT WERE DISCOVERED IN 1906 WITH ONLY A FEW MTS OF RICH ORE EXTRACTED; THE IMPORTANT GIBSON ALLUVIAL DEPOSIT, DISCOVERED IN 1938, HAD A SN RICH BASAL GRAVELS WHICH WERE WORKED THROUGH A SERIES OF SHAFTS; WATER SHORTAGE PLAGUED THESE OPERATION AS IT WAS COLLECTED USING RAIN WATER CATCHMENTS; METAL EXPLORATION N.L. CARRIED OUT EXPLORATION DRILLING AND FEASIBILITY STUDY IN 1976 ON THE GIBSON ALLUVIAL DEPOSIT; THE LOCAL WATER SHORTAGE PROBLEM WAS RESOLVED BY CONSTRUCTING A 51 KM PIPELINE FROM LAKE CARGELLIGO; MINING BEGINNING IN 1968; THE DRY GROUND ALLOWED LARGE, UNCASED BORES FOR RESERVED DELINEATION; RUBBER TIRED SCRAPERS AND BULL-DOZERS WERE USED IN MINING; GRAVELS PROCESSED USING CONVENTINAL GRAVITY SEPARATION PLANT; FINAL TIN CONCENTRATIONS IS QUITE CLEAN (75 PERCENT SN) DUE TO EASE OF SEPARATION OF RELATIVELY COARSE CASSITERITE FROM FINER-GRAINER HEAVEY MINERALS; THE OVERBURDEN TO ORE RATIO IN MINING THROUGH 1972 AVERAGED 14.45 TO 1; THE OVERBURDEN TO ORE RATIO FOR
RESERVED IDENTIFIED IN 1972 IS 9 TO 1.

Reference information

Links to other databases

Agency	Database name	Acronym	Record ID	Notes
USGS	Mineral Resources Data System	MRDS	TC39285

Bibliographic references

Deposit

LADEIRA, E.A., 1988, METALOGENIA DOS DEPOSITOS DE QUADRILATERO FERRIFERO, MINAS GERAIS, IN PRINCIPAIS DEPOSITAS MINERAIS DO BRASIL, C. SCHOBBENHAUS AND C.E.S. COELHO, ED., P. 301-375
Other Database

CIMRI

General comments

Subject category	Comment text
Deposit	MINABLE GRAVEL AT GIVSONVALE DEPOSIT ARE OVER 6 KM LONG, AVE. 120 M WIDE, AND 6 TO 32 M THICK (AVE. 18 M); GRAVELS HAVE BEEN CEMENTED BY IRON AND SILICA ABOUT 20 CM ABOVE BASEMENT AND HAS A THICKNESS BETWEEN 25 CM TO 2 M; STREAM GRADE AVERAGES 1 IN 150 FOR THE FIRST 4 KM FROM THE HEAD OF THE STREAM; RICHEST MINERALIZATION IN GRAVELS AT HIGHEST GRADIENTS; BASEMENT IS WEATHERED GRANITE WITH SCOUR HOLES, RAPIDS, AND STEEP BANKS
Deposit	MODELING NOTES: OVERALL SIZE OF GIBSONVALLE ALLUVIAL DEPOSIT INCLUDING DRAFT AND SURFACE MINING PRODUCTION AND RESERVES IS ESTIMATED AT 910,000 CM WITH 6.1 KG/CM SN METAL; THE SN GRADE IS HIGH AND DUE TO RICH BASAL GRAVELS.
Deposit	ADITS LIE ON N-S TREND

Reporter information

Type	Date	Name	Affiliation	Comment
Reporter	01-OCT-1993	Page, Norman J.	U.S. Geological Survey

Beyond USGS

Supplemental information added by qvyshift.com. Not part of the original USGS MRDS record.