Middle Bronze Age humidity and temperature variations, and societal changes in East-Central Europe

Abstract

Archaeological evidence points to substantial changes in Bronze Age societies in the European-Mediterranean region. Isotope geochemical proxies have been compiled to provide independent ancillary data to improve the paleoenvironmental history for the period of interest and support the interpretation of the archaeological observations. In addition to published compositions, in this study we gathered new H isotope data from fluid inclusion hosted water from a stalagmite of the Trió Cave, Southern Hungary, and compared http://www.sciencedirect.com/science/article/pii/S1040618217309448 the H isotope data with existing stable isotope and trace element compositions reported for the stalagmite. Additionally, animal bones and freshwater bivalve shells (Unio sp.) were collected from Bronze Age archaeological excavations around Lake Balaton and their stable C and O isotope compositions were measured in order to investigate climate changes and lake evolution processes during this period. The data indicate warm and humid conditions with elevated summer precipitation around 3.7 cal ka BP (Before Present, where present is AD 1950), followed by a short-term deterioration in environmental conditions at about 3.5 cal ka BP. The environment became humid and cold with winter precipitation dominance around 3.5 to 3.4 cal ka BP, then gradually changed to drier conditions at ~3.2 cal ka BP. Significant cultural changes have been inferred for this period on the basis of observations during archaeological excavations. The most straightforward consequences of environmental variations have been found in changes of settlement structure. The paleoclimatological picture is well in line with other East-Central European climate records, indicating that the climate fluctuations took place on a regional scale.

Speleothem Stable Isotope Records from Eastern Europe & Turkey

“…Trace element variability in speleothems from the region provided basis for paleohydroclimate implications [10][11][12], supported the identification of historical flood events [13]. Siklósy et al [14] associated a sudden rise in rare earth elements with the Middle Bronze Age eruption of Santorini.…”

“…Mecsek Hills, two from the Abaliget- [48] and one from the Trió Cave [11,14]. The relative data scarcity in the mid-Balkans ( Figure 1) could be reduced since studies have been recently published from Macedonia [50], Croatia [51] and Bosnia [52] (Table 1).…”

“…For a general introduction to environmental controls on speleothem δ 18 O the reader is referred to (LEAD PAPER to be cited). Variations of δ 13 C primarily interpreted by changes in paleohydrology, such as soil biological activity (Abaliget Cave [48], Ascunsă Cave [47], Baradla Cave [63]Trio Cave [11], Skala Marion Cave [45], Mavri Trypa Cave [44], Kapsia Cave [13] related to humidity changes or simplified to corresponding low/high δ 13 C values with dry/wet periods (Ursilor Cave [31], Modrič Cave [43]. For instance, P contents of the Trió speleothem supported that the δ 13 C values reflect humidity-related changes in soil biological activity [11].…”

“…As a result, δ 2 H values were used for paleotemperature calculations either applying local δ 2 H-temperature relationships, or combining the δ 2 H data with calcite δ 18 O values [11,18]. These procedures yielded paleotemperature estimates in agreement with independent methods both for the last interglacial [18] and the Middle Bronze Age [11].…”

“…An important methodological recognition is that hydrogen isotope compositions provide reliable paleoclimate records, while δ 18 O data are compromised due to post-deposition recrystallization and calcite-water isotope exchange [22]. As a result, δ 2 H values were used for paleotemperature calculations either applying local δ 2 H-temperature relationships, or combining the δ 2 H data with calcite δ 18 O values [11,18]. These procedures yielded paleotemperature estimates in agreement with independent methods both for the last interglacial [18] and the Middle Bronze Age [11].…”