|Latitude & Longitude (WGS84):||18° 30' 33'' South , 46° 58' 22'' West|
|Latitude & Longitude (decimal):||-18.50917,-46.97278|
|Köppen climate type:||Aw : Tropical savanna, wet|
|Name(s) in local language(s):||Ribeirão Santo Antônio do Bonito|
This locality has produced several of the largest diamonds ever found in Brazil, all coming from Quaternary alluvial deposits in the valley of the St. Antônio Bonito River. The geographic coordinates listed are for the site where the largest Brazilian diamond was found (the "Presidente Vargas," at 726.6 ct). Alluvial deposits along the stream also produced the "Darci Vargas" at 460.0 ct. (second largest), "Coromandel IV" at 400.5 ct. (fifth largest), "Diário de Minas" at 375.0 ct. (sixth largest), "Bonito I" at 346.0 ct. (ninth largest), and Vitório II at 328.0 ct. (tenth largest), but not all at the same site. Fernandes et al. (2014) showed locations of nine quarries (called "garimpos" in Brazil), both active and inactive, located 21-28 km ESE of Coromandel along the river.
NK, January 2017
6 valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
1000 - 1600 Ma
|Mesoproterozoic crystalline metamorphic rocks|
Age: Mesoproterozoic (1000 - 1600 Ma)
Lithology: Low grade unclassified metamorphic rock
Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529.