Trace-element, rare-earth element and boron isotopic compositions of tourmaline from a vein-type Pb–Zn–Cu ± U deposit, NE Turkey

Abstract

This paper reports trace-element, rare-earth element (REE) and boron isotopic compositions of tourmaline in the Asarcık granitoid and quartz veins at Şebinkarahisar. Abundant tourmaline occurs in the vein-type Pb-Zn-Cu^U deposit, within the northeastern Pontide Metallogenic Belt, both within the Late Cretaceous Asarcık granitoid and in associated quartz-tourmaline veins. Tourmaline in the granitoid forms as rosettes up to 1.5 cm in diameter, whereas in quartz-tourmaline veins a few centimetres to a few metres wide, it occurs as black needles and masses that cut the pluton. We present a systematic geochemical study of these tourmalines -all of the schorl-dravite series. Tourmalines from the quartz veins contain high concentrations of ore metals such as Ag, Bi and Zn and have higher Sr, Cr and Sn contents than tourmalines in the Asarcık granitoid. Tourmalines from intensively altered parts of the pluton are characterized by higher concentrations of trace elements such as Ba, Rb, V, Sc, Th and Zr compared with occurrences in the quartz veins and in the fresh and less-altered granitoid. Chondritenormalized patterns of REEs in tourmalines from the Asarcık granitoid are generally similar to those of tourmalines in the quartz veins. All vein tourmalines, however, are characterized by heavy REE enrichments, in sharp contrast to those in the granitoid. Boron isotopic compositions of tourmalines range from 214.0 to 22.2‰ and fall within the d 11 B range of this mineral in granite-related settings. Tourmaline rosettes from the Asarcık granitoid show relatively lighter d 11 B values (214.0 to 212.2‰) in comparison with those in the quartz veins (210.4 to 22.2‰).

Epigenetic gold occurrence in a Paleoproterozoic meta-evaporitic sequence in the Rompas-Rajapalot Au system, Peräpohja belt, northern Finland

“…Trace elements, especially the REE in tourmaline, provide important information on the environment of tourmaline formation (e.g., Yavuz et al, 2011;Hazarika et al, 2015;Kalliomäki et al, 2017). Laser ablation single collector inductively coupled plasma mass spectrometry (LA-SC-ICP-MS) was applied to measure REE contents of tourmaline using a Nu AttoM SC-ICP-MS instrument (Nu Instruments Ltd., Wrexham, UK) connected to an Analyte 193 ArF laser ablation system (Photon Machines, San Diego, USA) at the Geological Survey of Finland (GTK).…”

Distributions of Y + REE and Sc in tourmaline and their implications for the melt evolution; examples from NYF pegmatites of the Třebíč Pluton, Moldanubian Zone, Czech Republic

“…Based on the published data, the absence of any characteristic REE pattern for tourmaline is evident (e.g., King et al 1988;Yavuz et al 1999;Torres-Ruiz et al 2003;Raith et al 2004;Pesquera et al 2005;Ertl et al 2006;Yavuz et al 2011;Čopjaková et al 2013), which indicates that the tourmaline structure does not prefer any specific REE. In tourmalines from granitic pegmatites, extensive variations of La N /Yb N (0.16-433) as well as variable Eu/Eu* (0.005-16) were reported (Jolliff et al 1987;Hellingwerf et al 1994;Roda et al 1995;Ertl et al 2006;Bačík et al 2012).…”

“…The contents of REE in tourmalines were commonly analyzed from bulk samples (dissolved tourmaline separates) using ICP-MS or RNAA (Jolliff et al 1987;King et al 1988;Hellingwerf et al 1994;Roda et al 1995;TorresRuiz et al 2003;Raith et al 2004;Pesquera et al 2005;Ertl et al 2006;Garda et al 2010;Yavuz et al 2011). Consequently, they may be affected by the presence of accessory minerals inclusions (Pesquera et al 2005).…”

“…Published Y + REE data for tourmaline from granitic rocks (e.g., Yavuz et al 1999;King et al 1988;Raith et al 2004;Pesquera et al 2005;Yavuz et al 2011) or granitic pegmatites (e.g., Jolliff et al 1987;Hellingwerf et al 1994;Roda et al 1995;Ertl et al 2006;Novák et al 2011;Bačík et al 2012) are uncommon. Compositional trends in tourmalines from granitic pegmatites based on the concentrations of Y + REE and REE patterns in relation to pegmatite family (LCT or NYF), degree of fractionation, and tourmaline origin (magmatic or hydrothermal) are poorly understood (e.g., Jolliff et al 1987;Bačík et al 2012).…”

Chemical composition of tourmaline in orogenic gold deposits

“…Several studies document the major and minor element composition, but only a few report trace element compositions of tourmaline from orogenic gold deposits (Jiang et al 2002;Deksissa and Koeberl 2004;Hazarika et al 2015;Hazarika et al 2016;Manéglia 2017;Kalliomäki et al 2017). The trace element composition of tourmaline from various environments and deposit types are also available, including porphyry Cu-Mo (Koval et al 1991;Yavuz et al 1999;Iveson et al 2016), VMS (Hellingwerf et al 1994;Griffin et al 1996;Slack et al 1999), Sn skarn (Jiang et al 2004), SEDEX (Griffin et al 1996;Klemme et al 2011), W-Sn (Harlaux 2016;Duchoslav et al 2017;Hong et al 2017); Sn (Harlaux et al 2018;Harlaux et al 2019); polymetallic Pb-Zn-Cu±U (Yavuz et al 2011); polymetallic Sn-Ag-Pb-Zn (Jiang et al 1999); U unconformity-related (Joyce 2016) deposits, pegmatites (Jolliff et al 1987; Roda et al 1995;Roda-Robles et al 2004;Roda-Robles et al 2011;Bačik et al 2012;Gadas et al 2012;pegmatitic dikes (Ravenelle et al 2010;Dubé et al 2011;Ravenelle 2013;Fontaine et al 2015). Additional samples include tourmaline from the Lincoln Hill gold deposit in the Humboldt Range (Nevada, USA) that has epithermal characteristics (R. Taylor, pers comm, 2015).…”