Browsing by Author "Luoto, Toni"

Yeniyaylacık and Sofular localities in southeast of Central Anatolia are yielded with rich and wellpreserved late Neogene mammal fossils including bovids, equids, suids and rhinos. Faunal compositions of these sites are distinct from each other and biostratigraphy is still under study. The age and correlation of the Sofular ignimbrite underlying the studied Sofular section has been contentious in previous studies. For Yeniyaylacık section there are no previous detailed ages published. In this study, the magnetostratigraphic results are presented for the Yeniyaylacik and Sofular sites. The sampled Sofular section (located in 38°43’35” N, 35°00’30” E) is overlaying the Sofular Ignimbrite. In total 83 samples were taken from this ca. 51-meters-thick section, which is composed of thinly bedded and laminated siltstones and siliceous claystones with a few sandstone intercalations. Upper parts are more calcareous and dominated with limestone and claystone beds containing gypsum crystals. In total 32 samples were taken from ca. 8-meters-thick Yeniyaylacık section (located in 38°45’35” N, 34°37’04” E), comprised of muddy-clayey sediments with few thin limestone-sandstone units interbedded in the succession. Grain size of the samples was estimated based on Udden-Wentworth scale and color based on Munsell color chart. Carbonate content of the samples was estimated using 10 % hydrochloric acid. Magnetic susceptibility of each sample was measured using SM 150 susceptibility meter. 2G SQUID magnetometer was used to stepwisely demagnetize the samples. Thermomagnetic analyses were done using KLY-3S kappabridge for selected samples to identify magnetic mineralogy of the sections. Rock magnetic studies revealed that samples located at higher levels were clearly less magnetic in both of the sections, which correlates well with the increased carbonate content. Magnetic mineralogy of the samples consists mostly of Ti-poor titanomagnetite, but some of the samples also contained some hematite. AF-demagnetization results indicated that reversed polarity dominates the lower ca. 15 m in the Sofular section. The upper 35 m of the section is dominated by normal polarity. In the Yeniyaylacık section, reversed polarity dominates the whole section. Based on earlier studies and paleomagnetic results from this study, correlation with chron C4n.2n (8,1–7,7 Ma) or C3An.2n (6,7–6,4 Ma) is suggested for the long period of normal polarity in Sofular section. Less derived morphology of the Yeniyaylacık fauna suggests older age for the Yeniyaylacık fauna, so correlation with chron C4r (8,8–8,1 Ma) is suggested for long period of reversed polarity in the Yeniyaylacık section.