Establishing a TEPHROstratigraphy for the Eastern Anatolian Volcanic Provenance | TephroBridge

TephroBridge aims to geochemically characterise visible tephra layers (tephra = fine grained volcanic ash, formed during an explosive volcano eruption) from Lake Van's ICDP sediment core 5034-2, drilled on the Ahlat Ridge (AR). ICDP is the International Continental Scientific Drilling Programme.

The tephra layers detected in sediments from Lake Van are termed as V-layers. Tephra layers are a powerful chronological tool. Throughout the Mediterranean region, numerous palaeoclimate and archaeological records have recorded volcanic glass shards in their sedimentary records as possibly coming from the Eastern Anatolian Volcanic Provenance (EAVP), mainly from the Nemrut volcano. However, this region´s past eruptions are highly understudied. By providing geochemical data from V-layers identified over the last 30,000-130,000 years in Lake Van, we can use tephra layers or glass shards found in important palaeoclimatic records across the Mediterranean, particularly the ICDP Dead Sea cores, to understand the timing of past climate change across the region.

Location of Lake Van and other important archaeological and palaeoenvironmental published records (rectangles) that have mentioned tephra layers with potential Nemrut or Süphan correlations.
Location of Lake Van and other important archaeological and palaeoenvironmental published records (rectangles) that have mentioned tephra layers with potential Nemrut or Süphan correlations. (Graphic: R. Kearney with Google Earth Pro (Version 7.3.6.9750, release date 2024) with data provided by SIO, NOAA, U.S. Navy, NGA, GEBCO and images from Landsat/Copernicus.)
Location of Nemrut and Süphan volcanoes close to Lake Van and the location of the PALEOVAN 5034-2 ICDP core, Ahlat Ridge.
Location of Nemrut and Süphan volcanoes close to Lake Van and the location of the PALEOVAN 5034-2 ICDP core, Ahlat Ridge. (Graphic: R. Kearney with Google Earth Pro (Version 7.3.6.9750, Published 2024) with data from SIO, NOAA, U.S. Navy, NGA, GEBCO and images from Landsat/Copernicus.)
Nemrut Vulkan am Van See, Turkey
Nemrut Vulkan am Van See, Turkey (Photo: R. Kearney)
Sequence of explosive volcanic deposits at Lake Van, Eastern Anatolia, Turkey
Sequence of explosive volcanic deposits at Lake Van, Eastern Anatolia, Turkey (Photo: M. Schwab)
Photo (image center) of a microscopic cryptotephra shard (volcanic ash, transmitted light microscopy) with a diameter of ~60µm across from the Dead Sea lake sediments, Israel.
Photo (image center) of a microscopic cryptotephra shard (volcanic ash, transmitted light microscopy) with a diameter of ~60µm across from the Dead Sea lake sediments, Israel. (Photo: R. Kearney)
A volcanic glass shard (transmitted light microscopy) from an eruption of Süphan volcano around 87,000 years ago, found in the lake sediments of Lake Van, Turkey.
A volcanic glass shard (transmitted light microscopy) from an eruption of Süphan volcano around 87,000 years ago, found in the lake sediments of Lake Van, Turkey. (Photo: R. Kearney)
An SEM (scanning electron microscope) of a volcanic glass shard from the basaltic eruption of Incekaya maar around 80,000 years ago, found in the lake sediment of Lake Van, Turkey.
An SEM (scanning electron microscope) of a volcanic glass shard from the basaltic eruption of Incekaya maar around 80,000 years ago, found in the lake sediment of Lake Van, Turkey. (Photo: R. Kearney)
An SEM (scanning electron microscope) of two volcanic glass shards from the eruption of Nemrut around 120,000 years ago, found in the lake sediment of Lake Van, Turkey.
An SEM (scanning electron microscope) of two volcanic glass shards from the eruption of Nemrut around 120,000 years ago, found in the lake sediment of Lake Van, Turkey. (Photo: R. Kearney)
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In this project we want to carry out major and trace element analyses of volcanic glass from the tephra layers V-10 to V-93 found in the sediment core and characterise the glass shards morphologically. Expeditions to Lake Van will also be carried out as part of the project. The aim of the expeditions is to sample important tephra outcrops from the volcanoes Nemrut (2948 m a.s.l.) and Süphan (4058 m a.s.l.) located in the immediate vicinity of Lake Van (1648 m a.s.l.). These samples will complement the V-layers analysed in ICDP sediment core 5034-2. This will also include outcrops that have already been analysed as part of previous work in the PALEOVAN project. Many of these outcrops have been directly dated with ArAr, but there is a lack of geochemical glass shard data that can be correlated with the V-layers from the sediment core.

Once the geochemical analysis has been undertaken on the Lake Van ICDP sediment core, precise correlation to cryptotephra layers found in the ICDP Dead Sea sediment core will be conducted. As part of the TephroMed project, several cryptotephra glass shards (cryptotephra = a tephra, not visible to the naked eye) had chemical compositions similar to tephra particles of Nemrut volcano. Yet no direct correlation to a V-layer could be made due to the lack of geochemical information from the Lake Van ICDP sediment core. The new data from TephroBridge should provide correlations between Lake Van and the Dead Sea records as well as additional records found throughout the Mediterranean region.

  • 2024 - 2026

  • German Research Foundation (DFG) - Infrastructure Priority Programmes, Subproject of: SPP 1006 - International Continental Scientific Drilling Program (ICDP) SCHW 1183/3-1 / TJ 66/5-1 / BR 2208/18-1

  • Kearney, R., Goff, J., Smith, V., Schwab, M. J., Özdemir, Y., Karaoǧlu, Ö., Thirlwall, M., Barfod, D. N., Appelt, O., Günter, C., Fietzke, J., Pickarski, N., Neugebauer, I., Tjallingii, R., Brauer, A. (2025): Glass geochemistry and tephrostratigraphy of key tephra layers in and around Lake Van, Eastern Anatolian Volcanic Province (EAVP).- Quaternary Science Reviews, 352, 109165. https://doi.org/10.1016/j.quascirev.2024.109165

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