Trace element contents and C-O isotope geochemistry of the different originated magnesite deposits in Lake District (Southwestern Anatolia), Turkey


Kuscu M. , CENGİZ O. , KAHYA A.

ARABIAN JOURNAL OF GEOSCIENCES, cilt.10, 2017 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 10 Konu: 15
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1007/s12517-017-3102-1
  • Dergi Adı: ARABIAN JOURNAL OF GEOSCIENCES

Özet

Vein-stockwork magnesite in the Madenli area, sedimentary huntite-magnesite in the Asagitirtar area, and lacustrine hydromagnesite in the Salda Lake area are located in the Beysehir-Hoyran and Lycian nappe rocks around Isparta and Burdur, Southwest Anatolia. The aim of this study is to understand trace element contents and carbon-oxygen isotope ratios in different originated magnesite, magnesite bearing huntite, and hydromagnesite deposits. Also, the element contents and isotope ratios of the magnesite occurrences are to compare with each other and similar magnesite occurrences in Turkey and world. It is found that the Madenli magnesite occurrences in the Sarkikaraagac ophiolites, Asagitirtar magnesite bearing huntite deposits in the lacustrine rocks of the Miocene-Pliocene, and the Salda hydromagnesite deposits in lacustrine basin on the Yesilova ophiolites. The paragenesis contains a common carbonate mineral magnesite, less calcite, serpentine, smectite, dolomite, and talc in the Madenli magnesite occurrences, mostly huntite and locally magnesite, dolomite, calcite, illite, quartz, and smectite in the Asagitirtar huntite-magnesite occurrences, and only hydromagnesite mineral in the Salda Lake hydromagnesite occurrences. Vein and stockwork Madenli magnesite deposits were recognized by higher total iron oxide concentrations (mean 1.10 wt%) than sedimentary Asagitirtar magnesite bearing huntite (mean 0.13 wt%) and lacustrine Salda hydromagnesite (mean 0.22 wt%) deposits. It is suggested that high Fe content (up to 5%) in the magnesite associated with ultramafic rocks than those from sedimentary environments (<= 1% Fe). Based on average Ni, Co, Ba, Sr, As and Zr contents in the magnesite deposits, average Ni (134.63 ppm) and Co (15.19 ppm) contents in the Madenli magnesite and Salda hydromagnesite (36.85 ppm for Ni, 3.15 ppm for Co) have higher values than Asagitirtar huntite + magnesite (7.67 ppm for Ni and 0.89 ppm for Co). Average Ni-Co contents of these deposits can have close values depending on ophiolite host rock. Average Ba values of the Madenli (108.09 ppm) and Asagitirtar (115.88 ppm) areas are higher than those of Salda hydromagnesite (13.15 ppm). Sediment-hosted Asagitirtar magnesite-huntite deposits have the highest Sr contents (mean 505.81 ppm) as reasonably different from ultrabasic rock-related Madenli magnesite (mean 38.76 ppm) and Salda hydromagnesite (mean 36.70 ppm). The highest Sr content of sedimentary Asagitirtar deposits reveals that Sr is related to carbonate rocks. As and Zr contents have the highest average values (As 52.76 ppm and Zr 9.67 ppm) in the Asagitirtar deposits different from Madenli magnesite (As 0.54 ppm and Zr 1.67 ppm) and Salda hydromagnesite (As 0.5 ppm and Zr 2.58 ppm) deposits. High As and Zr concentrations in the Asagitirtar magnesite-huntite deposits may come from volcanic rocks in near country rocks. The delta C-13 (PDB) isotope values vary between -10.1 and -11.4 parts per thousand in the Madenli magnesite, 7.8 to 8.8 parts per thousand for huntite, 1.7 to 8.3 parts per thousand for huntite + magnesite and 4.0 parts per thousand for limestone + magnesite in the Asagitirtar huntite-magnesite deposits, and 4.4 to 4.9 parts per thousand for Salda Lake hydromagnesite. The sources of the CO2 are hydrothermal solutions, meteoric waters, groundwater dissolved carbon released from fresh water carbonates and marine limestone, soil CO2, and plant C3 in the Madenli magnesite, and may be deep seated metamorphic reactions in limestone and shales of rich in terms of organic matter.