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7095452 
Journal Article 
Nb-rutile: a reference mineral for timing of Sn, Nb-Ta, U-Th and REE mineralization at NW part of the Amazonian Craton 
Franco, JA; Cramer, T; Bonilla, A; Piraquive, A; Campos, H; , 
2019 
SOC GEOLOGY APPLIED MINERAL DEPOSITS-SGA 
GENEVA 4 
1248-1251 
WOS:000503111600327 
U/Pb ages measured by means of LA-ICP-MS in Nb-rutiles cogenetic with cassiterite, columbite and REE minerals proved to be a powerful tool for dating rock-forming and mineralization events. In four different locations grains of Nb-rutile were extracted from duricrust LOC (2) Cachicamo, from colluvial deposit Cerro Espina LOC (4), from colluvial and pegmatitic dykes San Jose LOC (5) and from colluvial deposit Barranquilla LOC (6) (Fig. 1). Metallographic and SEM - EDX analyses have revealed that most of the rutiles-Nb contain Fe-columbite inclusions and in some cases tantalite and cassiterite up to 0.2 mm length. The geochemical data for major oxides and trace elements was obtained using FRX-EPMA and ICP-MS, respectively. The results revealed a different variation regarding the TiO2, Nb2O5 Ta2O5, Fe2O3 and SnO2 contents of the matrix. The measurements in single Nb-Ta rutile crystals for each locality yielded enough U, Pb and Th for LA-ICP-MS analyses that were performed at the University of Rennes 1 and in ETH Zurich. There, 40 Nb-Ta rutile crystals were dated obtaining concordant U/Pb ages coherent with rocks and mineralization. 
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15th SGA Biennial Meeting on Life with Ore Deposits on Earth 
Glasgow, SCOTLAND