U-Pb Geochronology of Silica Undersaturated Rocks - from the Discovery of Baddeleyite to its Potential Application as a Geochronometer in Brazil

The U-Pb geochronology advent changes the geology as gave it reliable and precise ages. The methodology wide spread use zircon as main datable mineral. Its features make the data easier to use and is commonly found on high silica igneous and metamorphic rocks and sediment provenience. However, there is a remarkable limitation – it is rare or absent on silica sub saturated rocks. Many minerals have been used when zircon is not found, as monazite and perovskite, but baddeleyite stands out. Baddeleyite has the save features on geochronology as zircon, and is found on silica sub saturated rocks, but is hard to concentrate on classical methods. On 2002 a brand-new methodology, know as “Söderlund” to concentrate baddeleyite was published that boosted its use, but it was constrained mainly on North America, Europe and Australia. Since 2017, Brazilian survey adapted this new methodology to the country reality using a Wilfley Table and became able to separate baddeleyite. This paper presents on details this adapted methodology that is also able to concentrate zircon on samples where the classical methodology was not efficient.