Niğde Ömer Halisdemir Üniversitesi Mühendislik Bilimleri Dergisi
Yazarlar: Murat ÇİFLİKLİ
Konular:Mühendislik
DOI:10.28948/ngumuh.502345
Anahtar Kelimeler:: pillow lava,Basaltic volcanism,Alteration,Phyllosilicate
Özet: Within the Paleocene Ulukışla formation in the Kavuklu (Ulukışla-Niğde) region, basaltic rocks which are products of pillow lavas that formed during marine volcanism are widely exposed. In the pillow lava lobes, an intense alteration is usually observed on the outer surface with a decreasing alteration trend towards the core. In this study, mineralogical-petrographic properties of basaltic rocks with pillow-shaped lava-like appearance and alteration properties of volcanic rocks influenced by seawater interaction were investigated. The textural properties were determined using optical and scanning electron microscope (SEM), mineralogical (X-ray diffraction-XRD), and chemical (X-ray fluorescence spectrometry-XRF). According to the optical microscope studies, phyllosilicate occurrences, mostly chlorite and less biotite, in the form of cracks and voids and/or pore fills were observed in the samples where alteration was common. Chlorites have completely substituted ferromagnesian minerals in places. The carbonate and quartz minerals observed in the form of cracks and pore fills represent the last phase of alteration products that developed after phyllosilicates. XRD clay fraction studies have shown that phyllosilicate minerals are composed of chlorite, mixed bedded chlorite-smectite (C-S, corrensite), and illite/mica. Phyllosilicate associations consist of chlorite, chlorite ± C-S, chlorite ± illite, and chlorite ± C-S ± illite. SEM results revealed that chlorites were characterized by 2-10 μm size, flakes shaped communities. The findings showed that the pillow-structured basalts developed at the seafloor and the subsequent Fe-Mg contents of the marine volcanic rocks developed from the high magmatic components of Fe and Mg (trioctahedral) of the phyllosilicate minerals. The fracture / pore-filling carbonate minerals representing the later stage seem to be related to the presence of basaltic rocks in the marine environment.