Detection and Characterisation of Eemian Marine Tephra Layers within the Sapropel S5 Sediments of the Aegean and Levantine Seas

Abstract

The Eemian was the last interglacial period (~130 to 115 ka BP) to precede the current interglacial. In Eastern Mediterranean marine sediments, it is marked by a well-developed and organic-rich “sapropel” layer (S5), which is thought to reflect an intensification and northward migration of the African monsoon rain belt over orbital timescales. However, despite the importance of these sediments, very little proxy-independent stratigraphic information is available to enable rigorous correlation of these sediments across the region. This paper presents the first detailed study of visible and non-visible (cryptotephra) layers found within these sediments at three marine coring sites: ODP Site 967B (Levantine Basin), KL51 (South East of Crete) and LC21 (Southern Aegean Sea). Major element analyses of the glass component were used to distinguish four distinct tephra events of Santorini (e.g., Vourvoulos eruption) and possible Anatolian provenance occurring during the formation of S5. Interpolation of core chronologies provides provisional eruption ages for the uppermost tephra (unknown Santorini, 121.8 ± 2.9 ka) and lowermost tephra (Anatolia or Kos/Yali/Nisyros, 126.4 ± 2.9 ka). These newly characterised tephra deposits have also been set into the regional tephrostratigraphy to illustrate the potential to precisely synchronise marine proxy records with their terrestrial counterparts, and also contribute to the establishment of a more detailed volcanic history of the Eastern Mediterranean.

The Medial Offshore Record of Explosive Volcanism Along the Central to Eastern Aegean Volcanic Arc: 2. Tephra Ages and Volumes, Eruption Magnitudes and Marine Sedimentation Rate Variations

“…The erupted magma volume responsible for caldera subsidence has been estimated as ∼60 km 3 DRE (Allen et al, 1999;Nomikou, Croff Bell, et al, 2013). We correlated tephra layer CA18 in four POS 513 cores west of Kos with the KPT, and KPT ash has also been recognized in many other Aegean and Mediterranean cores by Federman and Carey (1980), Hardiman (1999), Margari et al (2007), Satow et al (2015Satow et al ( , 2020, Vinci (1985), and Wulf et al (2020) as well as in the southeastern Black Sea (Wegwerth et al, 2019). Using all these marine data, and the proximal thickness of fall unit A, the area (within the 1 cm isopach) is 5.3 × 10 5 km 2 (Figure 6b).…”

“…Using the data of Satow et al. (2015, 2020), we were able to identify US2 ash in their core LC21 southeast of Santorini. Wulf et al.…”

“…(2007), Satow et al. (2015, 2020), Vinci (1985), and Wulf et al. (2020) as well as in the southeastern Black Sea (Wegwerth et al., 2019).…”

“…Another prominent black marine ash layer, CA10, which is 7-12 cm thick in seven cores west and east of Santorini, is the marine equivalent of Upper Scoriae 2 on land. Using the data of Satow et al (2015Satow et al ( , 2020, we were able to identify US2 ash in their core LC21 southeast of Santorini. Wulf et al (2020) observed US2 ash in core KL49 which lies closer to Santorini than LC21.…”

The Medial Offshore Record of Explosive Volcanism Along the Central to Eastern Aegean Volcanic Arc: 1. Tephrostratigraphic Correlations

“…We found this distal ash in cores POS 513-8, −9, −14, −15, −30, −31, −32, −35, −37, −40, −41, −45, −53, and −56 with thicknesses ranging from 3 to 14 cm (Figure 3c). CI distal ash has been found as layer Y-5 across most of the Mediterranean Sea (e.g., Engwell et al, 2014;Keller et al, 1978;Margari et al, 2007;Satow et al, 2020Satow et al, , 2015Vinci, 1985;Wulf et al, 2020).…”