International Workshop on Subduction Related Ore Deposits, Trabzon, Türkiye, 22 - 26 Eylül 2017, ss.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.