TY  - JOUR
TI  - Triassic-Jurassic arc magmatism in the Pontides as revealed by the U-Pb detrital zircon ages in the Jurassic sandstones of northeastern Turkey
AB  - The Eastern Pontides were located at the southern active margin of Laurasia during Mesozoic time. Jurassic volcaniclasticsediments and volcanic rocks of the Pontides represent products of the arc magmatism above a north-dipping subduction zone.Despite the wide distribution of the Jurassic volcaniclastic/volcanic succession, the precise age of the Jurassic volcaniclastic sequenceand that of the synsedimentary magmatism are poorly constrained. Here we present U-Pb detrital zircon ages from two Jurassicsandstones belonging to the Şenköy Formation of the Eastern Pontides. One sample is taken from the base of the Şenköy Formationunconformably overlying the late Carboniferous Gümüşhane granite. The depositional age of this sandstone is constrained as lateSinemurian-Pliensbachian based on the faunal assemblage of the overlying Ammonitico Rosso type carbonates. Detrital zircon grainsfrom this sample yielded an unexpected component of 203.4 ± 0.2 Ma (Latest Triassic, Rhaetian) U-Pb age, indicating the existenceof Late Triassic magmatic activity in the region that has not been reported yet from the exposed magmatic bodies or from the detritalzircon ages. The sample taken from the upper part of the Jurassic succession yielded a youngest U-Pb age component of 155.9 ± 1.8 Ma,indicating that the depositional age of the Jurassic volcaniclastic succession extends from the Early Jurassic (Sinemurian), as revealedby the fossil content and abundant U-Pb detrital zircon ages, to the Late Jurassic (Oxfordian-Kimmeridgian). The detrital zircon agesfrom this study together with those from the literature indicate arc magmatism on the southern margin of Laurasia during the Triassicand Late Jurassic (250–156 Ma).
AU  - AKDOĞAN, Remziye
AU  - Dunkl, István
AU  - OKAY, Aral I.
DO  - 10.3906/yer-1706-19
PY  - 2018
JO  - Turkish Journal of Earth Sciences
VL  - 27
IS  - 2
SN  - 1300-0985
SP  - 89
EP  - 109
DB  - TRDizin
UR  - http://search/yayin/detay/349237
ER  -