AGE, GEOCHEMISTRY, AND TECTONIC SIGNIFICANCE OF QUATERNARY BASALTS ASSOCIATED WITH TRANSFORM FAULTS OF THE ANATOLIA-ARABIA-AFRICA TRIPLE JUNCTION

Date

2022-10-11

Author

Cosca, Michael
Reid, Mary
Rojay, Fuat Bora

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

38
views

0
downloads

Cite This

Mafic volcanism, active seismicity, vigorous geothermal fluid circulation and mineralization are commonly associated with triple junctions. In this study we demonstrate that40Ar/39Ar dating of mafic volcanism associated with the Anatolia-Arabia-Africa triple junction (A3triple junction) can also be used to constrain the onset of tectonic escape of the Anatolian plate. The A3triple junction, located near the Gulf of İskenderunin the eastern Mediterranean,is a trench-transform-transform system that includes two major, dominantly left-lateral transform faults: the East Anatolian fault zone (the Anatolia-Arabia plate boundary) and the Dead Sea fault zone (the Arabia-Africa plate boundary). Quaternary alkaline basalt (including basanite) from the Toprakkale and Karasu volcanic fields are investigated within a broad zone of transtension associated with these plate boundary faults near the İskenderun and Amik Basins, respectively. Seismic velocities obtained primarily from the Continental Dynamics-Central Anatolian Tectonics project (CD-CAT) show abrupt contrasts in lithospheric thicknesses under the triple junction, from ~60 km beneath the Arabian margin to >100 km beneath central Anatolia. Here we present40Ar/39Ar geochronology, whole rock geochemistry, Sr, Nd, Hf, and Pb isotopes of basalts from each volcanic field and compare their mantle source regions and equilibration depths to the seismically imaged lithosphere-asthenosphere boundary. These results will be discussed within a broader context of regional magmatism and mantle structure associated with the inception and migration of the triple junction, which also has implications for dating tectonic escape of the Anatolian microplate.

URI

https://gsa.confex.com/gsa/2022AM/webprogram/Paper378434.html
https://hdl.handle.net/11511/107447

Collections

Department of Geological Engineering, Conference / Seminar