Buried amber finds in the coastal deposits of Saaremaa Island, eastern Baltic Sea – their sedimentary environment and possible use by Bronze Age islanders

Abstract

Here, we present new sedimentary data of the amber bearing layer from the Holocene coastal plain on the SW Saaremaa Island where amber is not known in sedimentary successions but is common in Stone Age and Bronze Age archaeological sites. A layer of buried organic matter (BOM), sandwiched between sandy coastal deposits and containing pieces of natural amber, was discovered during fieldwork and analysed in detail. Results show that the BOM layer is buried under approximately 90‐cm‐thick sandy coastal deposits and consists of the remains of different coastal plants. Palaeogeographical reconstructions and sediment compositions indicate that the layer was deposited in the coastal zone and buried quickly by sandy marine sediments. According to AMS radiocarbon dating of knotgrass seeds (Polygonum lapathifolium), deposition of the BOM layer took place in the Late Bronze Age; about 2.7–2.5 cal. ka BP. Infrared spectra and isotopic composition of the analysed amber from the BOM layer indicate Baltic amber, also known as succinite. The stable isotope ratio indicates the origin of the amber to be south of Estonia. Therefore, it is proposed that the amber was probably transported to Saaremaa within organic matter (along the main SW–NE orientated current flows) from the SE coast of the Baltic Sea where secondary Baltic amber deposits are known to exist widely. Amber items are common in Late Bronze Age settlement sites and burials in Saaremaa and are considered to originate from present‐day Latvia, Lithuania, Kaliningrad district (Russia) and Poland. The current study shows that during the Late Bronze Age natural amber accumulated in the coastal zone of Saaremaa Island and that the islanders could collect it. Therefore, the possibility exists that some Bronze Age archaeological amber objects could be made of local material as opposed to being a result of trade with southern neighbours, as formerly thought.

Late-Holocene relative sea-level changes and palaeoenvironment of the Pre-Viking Age ship burials in Salme, Saaremaa Island, eastern Baltic Sea

“…Results from Salme and the neighbouring archaeological and geological sites (Figure 1b) were used to reconstruct Late-Holocene RSL changes for Saaremaa Island (Figure 8). Altogether, 33 sea-level indicators were analysed (Table 3), including some previously published data from Salme burial sites (Konsa et al, 2009; Peets and Maldre, 2010), from the nearby Vintri amber deposit (Nirgi et al, 2017; Ots, 2012), from the fortified settlements in Asva (Lang and Kriiska, 2001) and Kuressaare (Püüa, 2013), and a typological age determination from the Viltina harbour site (Mägi, 2009). Annual average RSLs from the Virtsu tide-gauge station (Figures 1b and 8b) for the 20th century were also used in the RSL reconstruction (Tõnisson et al, 2019).…”

“…The RSL curve shows a nearly linear regressive trend since the Bronze Age due to the continuous glacial isostatic adjustment outpacing the declining rates of post-glacial absolute sea-level rise. Two radiocarbon dates from the buried organic bed in coastal deposits from the Vintri site (Nirgi et al, 2017) show the RSL to be around 5.5 m a.s.l. at about 700 BC.…”

“…In the Late Bronze Age (Figure 10a), at about 700 BC, the strait was up to 2 km wide and ca. 5 m deep and was probably part of the Bronze Age transportation network (Nirgi et al, 2017). In the south it was bordered by the Läätsa palaeoisland, and from the east by the slowly growing south-north orientated spit system.…”

“…The palaeostrait widens westwards to more than 2 km and the former coastline can be followed in the relief at an altitude of ca. 3.5 m (Nirgi et al, 2017). Our study area covers the narrowest (ca.…”

Gems and Placers—A Genetic Relationship Par Excellence

“…Holocene amber deposits are widespread along the coast of the Baltic Sea up to the Kuršių Marios lagoon. Nirgi et al (2017) [132] reported amber-bearing layers from the Holocene coastal plain on the SW Saaremaa Island where amber is not known in sedimentary successions, but is common in Stone Age and Bronze Age archaeological sites. Amber cannot be grouped among the heavy minerals and the rules of settling and entrainment equivalence can hardly be applied to the majority of these organic compounds (Figure 7).…”