International Workshop on Subduction Related Ore Deposits, Trabzon, Turkey, 22 - 26 September 2017, pp.1-5
The study area is located in the northern part of the Central Anatolian Crystalline Complex (CACC) at the border of İzmir-Ankara-Erzincan Suture Zone. Studied mineralizations occurred within Artova Ophiolite Complex (AOC). Manganese mineralizations that occur within radiolarites are banded, laminated and lenticular and are intensely fractured and folded. Manganese mineralizations are distributed over six different regions, namely Derbent, Baltasarilar, Cihanpasa (northwest of Yozgat), Buyukmahal (northeast of Yozgat), Eymir (Sorgun-Yozgat) and Tarhana (Kadisehri-Yozgat) where pyrolusite, psilomelane, manganite and braunite comprise the main paragenesis and jacobsite, magnetite and goethite are the minor phases.
Except for some of the Derbent samples, the other samples in the area show negative Eu anomaly. These values are indicative of insufficient interaction with volcanic rocks (basalt, diabase) during the mineralization while the negative and positive Eu anomalies recorded in the Derbent region would show contribution by hot hydrothermal fluids which increased the temperature. The negative Eu anomaly may also imply that hydrothermal source was distant from the mineralization or it may be highly mixed with seawater. Total 25 samples collected from Cihanpasa and Buyukmahal areas are represented by negative Ce anomaly and have resemblance to low-temperature hydrothermal deposits. Samples from the other deposits display both negative and positive Ce anomalies. Based on this both hydrothermal and hydrogenetic processes were effective in the formation of the mineralizations.
High Ba content and decreasing pattern from LREE to HREE together with negative Ce anomalies and trace element distributions indicate that mineralization in the area was derived from a primary hydrothermal source. In addition, diagenetic and epigenetic processes may also play an important role in the manganese deposition.