Abstract:

The study area is located in the Eastern Pontides between Rize, Çayeli, Arhavi, İspir and İkizdere. In this area, Maçka Tectonic Slice (MTS) and Taşköprü Tectonic Slice (TTS) are exposed. MTS is composed from old to young; Late Jurassic-Early Cretaceous limestone (Berdiga fm.); Turonian- Santonian conglomerate, sandstone, micritic limestone, siltstone, marl, basaltic, basaltic-andesitic lava, pyroclastites (Çatak fm.); Santonian rhyolitic, dacitic lava, pyroclastites, sandstone, clayey limestone (Kızılkaya fm.); late Santonian-Campanian basaltic, andesitic lava, pyroclastites, sandstone, clayey limestone (Caglayan fm.); Campanian-Mastrihtian rhyolitic, dacitic lava, pyroclastites, sandstone, clayey limestone (Çayırbağ fm.);late Maastrichtian-Danian sandstone, claystone, tuff, marl, clayey limestone (Cankurtaran fm.). Sedimentary, volcanosedimentary units in the Late Paleocene-Quaternary range (Erenler, Kaplıca, Melyat, Pazar, Hamidiye formations, and Handüzü, Çağırankaya volcanites) unconformably overlies the MTS. In the study area, Turonian- Maastrichtian basaltic andesitic lavaş, pyroclastites and sandstone, micritic limestone, claystone units (Yağmurdere fm.) belonging to TTS are observed, and Early-Middle Eocene sedimentary and volcanosedimentary units (Yedigöze, Çoruh formations) unconformably overlies the TTS. According to Ar/Ar dating, Çayırbağ formation was determined as 83.2±1.0 Ma, Melyat formation as 47.8±1.6 Ma, and Handüzü volcanics as 4.25±0.55 Ma for andesite level and as 3.93±0.46 Ma for dacite level. The MTS was intruded by Cretaceous-Paleocene Kaçkar granitoid I, Eocene Kaçkar granitoid II, Late Eocene Ardeşen gabbro, while the TTS was intruded by Cretaceous-Paleocene Kaçkar granitoid-I, Late Eocene Güllübağ monzonite.

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