Akademik Veri Yönetim Sistemi
WMESS 2021, Praha, Çek Cumhuriyeti, 6 - 10 Eylül 2021, ss.5
Low-grade metasedimentary rocks are exposed on
the southern part of the Biga Peninsula located in the northwest Turkey. The
low-grade metasedimentary rocks were analysed for their major, trace and rare
earth elements in order to reveal provenance and tectonic setting. Based on the
macroscopic and petrographic observations, low-grade metasedimentary rocks are
mainly composed of schist, phyllite, metabasite and marble intercalations.
Schists form the dominant lithology of metasedimentary rocks and are yellowish
brown-coloured, well-foliated and fine to medium-grained. The main
mineralogical composition of schist is quartz, K-feldspar, biotite and
muscovite. The abundance of K-feldspar within schist show that fast sediment
deposition took place from proximal source. Provenance discrimination diagrams
based on major element geochemistry and trace element ratios (i.e., Th/Sc, Zr/Sc,
Cr/V and Y/Ni) suggest that the sediments were derived from intermediate-felsic
source rocks. Similarly, the probable source areas of the low-grade
metasedimentary rocks are the crystalline basement of the Sakarya Zone in
northwest Turkey, which is composed of Devonian and Carboniferous magmatic and
metamorphic rocks. Tectonic setting discrimination diagrams based on major
elements, immobile trace elements (i.e., Th- Co- Zr/10 and Th-Sc-Zr/10) and
La/Y vs. Sc/Cr plots indicate that metasedimentary rocks were deposited in a
passive margin and oceanic island arc. According to the petrographical and
geochemical results, the metasedimentary rocks are suspected to have double
origin. One is continental bringing quartz and metamorphic fragments, and the
other one is volcanic-arc type responsible for feldspar, plagioclase and
volcanic fragments. In other words, the metasedimentary rocks of studied area
were derived from both volcanic arc and continental source areas, which refers
back-arc basin.