The Tafak manganese deposit (Dursunbey-Balıkesir, NW Turkey): implications for the submarine hydrothermal origin of İzmir-Ankara-Erzincan Neotethyan Ocean

In Turkey, radiolarian chert-hosted Mn-oxide deposits are exposed commonly within the deep-sea pelagic sediments belonging to the ophiolitic mélange units along northern branch of the Neotethys (İzmir-Ankara-Erzincan Suture Zone) in northern Turkey. In the Tafak region (Dursunbey, Balıkesir), Mn-deposit is currently mined from large- to medium- scale lenses (ca. 10 × 100 m) and interlayers with the mudstone and silicious pelagic sediments. This deposit comprises dominantly mineral assemblages of braunite, pyrolusite, and ganque minerals are quartz and rarely calcite. High Mn/Fe (437), Co/Zn (1.36), Co/Ni (2.04) ratios, low contents of ΣREE (27.7 ppm), Cu+Ni+Co (303 ppm), and also negative Ce anomaly (Ce/Ce* PAAS = 0.46), positive Y anomaly (Y SN /Ho SN = 1.33) with Y/Ho ratio (36.09) suggest that Tafak Mn deposit formed in a submarine hydrothermal system. Redox-sensitive element ratios (Ni/Co = 0.23-1.45, V/Mo = 2.63–20.81), positive Mn* SN (3.03–5.04), low Sr concentrations (82.2 ppm) and Ce anom. (− 0.52) values indicate that the Tafak Mn deposit was formed in low-salinity and oxygenated marine environment. Meanwhile, the presence of weakly negative Eu anomaly (0.94), Ce anomaly (0.46), and ΣREE/Fe ratio (127.8 x10 -4 ) suggests that low-temperature hydrothermal fluids (< 200 °C) in pelagic depositional site of the İzmir-Ankara-Erzincan Neotethyan Ocean were effective in formation of the Tafak manganese deposit.