Charred olive pits are frequently preserved in archaeological sites in Israel, from ca. 5000 BCE. As olive fruits grow during one season, the carbon comprising their pits reflects their year of growth, making charred olive pits found in situ ideal for radiocarbon dating of archaeological contexts. An additional aspect, up until now not explored, is utilizing the ratio between the stable carbon isotopes (δ13C) in these charred olive pits as a proxy for climate. Olive pits provide multiple advantages as a proxy, allowing for higher resolution of climate reconstruction, both spatially and temporally, reflecting the environment in which the olive trees were growing, and humans were living. Here we show firstly, an analysis of modern olive pits and assess the connection between pit cellulose δ13C and aridity index. Specifically, we identify the threshold Δ13C for olive trees under severe drought stress as below 15.5 ± 0.5‰. Next, as olive pits are usually found charred in archaeological contexts, we evaluated the effect of charring on the δ13C signal of the modern olive pits. Finally, we present Δ13C values of more than 500 charred olive pits from 51 archaeological sites in Israel, spanning ∼6000 years. Based on these values we have identified periods of arid conditions and wet conditions in the past.
|Journal||Quaternary Science Reviews|
|State||Published - 15 Oct 2022|
Bibliographical noteFunding Information:
The researchers wish to thank Prof. Dan Yakir from the Department of Earth & Planetary Sciences at the Weizmann Institute for granting permission to use his elemental analyzer, which was used for obtaining some of the δ13C values. We also wish to thank Itzhak Tor, who aided in locating olive trees for sampling in northern Israel. Additional thanks to Yossi Goldstein from the lab of Prof. Pedro Berliner from the Jacob Blaustein Institute for Desert Research at Ben-Gurion University, Sede-Boqer Campus, for their permission and help in locating olive trees growing in Mashash, as well as the input of floodwater data. The olives from Bet Dagan were from the collection of the late Prof. Shimon Lavee. We additionally wish to thank Dr. Uri Davidovich from the Institute of Archaeology at the Hebrew University of Jerusalem for the samples from the Gulgalot cave, and Dr. Naama Sukenik from the Israel Antiquities Authority for permission to sample olives from the organic material lab. Finally, thanks to Dr. Arnon Dag from the Agricultural Research Organization – Volcani Institute, for his guidance and help as an expert on olives throughout this work. The Radiocarbon research was supported by the Exilarch Foundation for the Dangoor Research Accelerator Mass Spectrometer (D-REAMS) Laboratory. Y.E. is supported by the Max Planck-Weizmann Center for Integrative Archaeology and Anthropology. H. R. is supported by the Kimmel Center for Archaeological Science. We wish to thank the Kimmel Center for Archaeological Science and George Schwartzman Fund for the laboratory and funding support for the material analysis. E.B. is the incumbent of the Dangoor Professorial Chair of Archaeological Sciences at the Weizmann Institute of Science.
Y.E. is supported by the Max Planck-Weizmann Center for Integrative Archaeology and Anthropology.
The Radiocarbon research was supported by the Exilarch Foundation for the Dangoor Research Accelerator Mass Spectrometer (D-REAMS) Laboratory.
H. R. is supported by the Kimmel Center for Archaeological Science.
© 2022 Elsevier Ltd
- Aridity index
- Carbon isotope
- Olive pits
- Southern levant