Akademik Veri Yönetim Sistemi
EGU General Assembly 2024, Vienna, Avusturya, 14 - 19 Nisan 2024, ss.111, (Özet Bildiri)
The Tethyan Phosphogenic Province is one of the widest of its kind, representing an outstanding
period of phosphate deposition principally in the Upper Cretaceous-Eocene period. The main aim
of this study is to compare the Turkish phosphorites occurring along the southern side of the Neo
Tethyan Ocean due to suitable seawater temperature and upwelling oceanic currents with
Albanian phosphorites were deposited in higher latitudes and colder climates, in the same ocean.
The Şemikan (Türkiye) phosphorites consist mainly of cream-coloured (CCP) and locally reddish
phosphorites (RP) occurring as lenses or concordant blankets within high-grade cream
phosphorites. Based on microscopic examination, cream-coloured phosphorites consist of
phosphatic pellets, intraclasts, bioclasts (fossilized shark teeth, ostracods etc.) and nonphosphatic
components, with texture changing from wackestone to packstone, testifying shallow marine
depositional environment. Whereas, Gusmari (Albania) phosphorites consist of laminated
phosphorites (LP), of mudstone/wackestone texture, with planktonic foraminifera
Globotruncanidae, where the phosphate is sedimentary, and alternating laminae of phosphate
and pelagic carbonate. Besides this, under SEM-EDS, 5μm crystals of the major ore of uranium,
UO2, were evidenced for the first time in LP. The mineralogical analyses showed that the CCP
consisted of carbonate-rich fluorapatite, minor calcite and quartz. The RP consisted predominantly
of carbonate-rich fluorapatite, hydroxyapatite, montmorillonite, and minor quartz. The LP
consisted predominantly of calcite, carbonate-rich fluorapatite, hydroxyapatite, and traces of
quartz. The mean P2O5 content of the CCP is 29%, RP and LP 14%, which is lower than that of other
well-known global phosphorite deposits. The CaO content of the CCP, RP and LP ore is also higher
than that of other global deposits because of a calcite matrix between phosphorite pellets. Based
on preliminary results of trace elements CCP, RP and LP show a general trace element scarcity
compared to the trace element averages of the world’s average phosphorites. The main reason for
this deficiency is the rapid sedimentation or high burial rate in the sedimentary basin, which
prevents the replacement of carbonate-rich fluorapatite by trace elements.