Timing of neotectonic fracturing by fission track dating of obsidian in-filling faults in the Ikizdere-Rize area, NE Black Sea region, Turkey

Abstract

There are several NE-SW- and NNW-SSE-trending sets of neotectonic faults that are infilled with obsidians in the Ikizdere-Rize district of the NE Black Sea region, Turkey. Using the fission-track technique, it is estimated that these fracture-filling obsidians were formed between 1.73 +/- 0.10 and 1.93 +/- 0.15 Ma. This short period is consistent with a unique eruption, and is supported by petrographic and geochemical data that reveal very homogenous characteristics. Although existing literature data indicate that these faults are part of the early Pliocene neotectonic fracture system in this region, the determination of latest Pliocene-Pleistocene formation for the Ikizdere obsidians better constrains its timing.