Strontium isotopes answer questions about the past: Holocene land use reconstruction in the Cape
By:
Maximilian Jan Spies
Date:
Tue, 13/05/2025 - 18:30
Venue:
SA Astronomical Observatory auditorium
Branch:
Western Cape
Charge: Free for members | R40 for nonmembers | R20 for student nonmembers
Link to the YouTube recorded talk: https://youtu.be/snvryqbnFNo
About the Talk:
Using isotopes of strontium (Sr) to investigate a sample’s provenance has become widespread in archaeology and other fields, as it is a useful indicator of origin that (mostly) tracks with geology. Other sources of Sr on the landscape include sea spray and dust deposited by marine and terrestrial winds. Importantly, the isotopic ratio of 87Sr/86Sr persists in the soils and the tissues of plants, animals, and humans that live and eat food from the area. To better understand the lives of coastal foraging communities on the west coast of the Cape, we built on previous work to develop a 87Sr/86Sr isoscape (or spatial model predicting isotopic ratios) for the coastal region of the Western Cape. The isoscape is based on Sr extracted from wild plants and has applications in archaeology, palaeoanthropology, ecology, and forensics. Using it to assess the 87Sr/86Sr of carbon-dated human skeletons found along the coast, a distinctive pattern emerges. Between 6120-2000 BP, we see coastal settlements of hunting and gathering communities, eating mainly marine foods. This aligns with previous evidence for a widespread pattern of territorial coastal foragers along the South African coastline in the late Holocene. However, from around 2000 BP, there is a more diverse and terrestrial 87Sr/86Sr signal, suggesting reduced reliance on marine foraging and increased consumption of foods from further inland. This aligns with the introduction of domesticated animals in the Cape. The rapid adoption of sheep and cattle herding brought significant changes to the spatial, economic, social, and political organisation of coastal societies.
Bio:
Dr Maximilian Jan Spies is a postdoctoral research fellow under Professor Judith Sealy in the Department of Archaeology at the University of Cape Town. He has recently been exploring the use of strontium isotopes to help answer questions about how people lived and moved across the landscape in the past. With his background in forensic anthropology, he hopes to expand into other isotope systems for use in forensic contexts.
Link to the YouTube recorded talk: https://youtu.be/snvryqbnFNo
Link to the YouTube recorded talk: https://youtu.be/snvryqbnFNo
About the Talk:
Using isotopes of strontium (Sr) to investigate a sample’s provenance has become widespread in archaeology and other fields, as it is a useful indicator of origin that (mostly) tracks with geology. Other sources of Sr on the landscape include sea spray and dust deposited by marine and terrestrial winds. Importantly, the isotopic ratio of 87Sr/86Sr persists in the soils and the tissues of plants, animals, and humans that live and eat food from the area. To better understand the lives of coastal foraging communities on the west coast of the Cape, we built on previous work to develop a 87Sr/86Sr isoscape (or spatial model predicting isotopic ratios) for the coastal region of the Western Cape. The isoscape is based on Sr extracted from wild plants and has applications in archaeology, palaeoanthropology, ecology, and forensics. Using it to assess the 87Sr/86Sr of carbon-dated human skeletons found along the coast, a distinctive pattern emerges. Between 6120-2000 BP, we see coastal settlements of hunting and gathering communities, eating mainly marine foods. This aligns with previous evidence for a widespread pattern of territorial coastal foragers along the South African coastline in the late Holocene. However, from around 2000 BP, there is a more diverse and terrestrial 87Sr/86Sr signal, suggesting reduced reliance on marine foraging and increased consumption of foods from further inland. This aligns with the introduction of domesticated animals in the Cape. The rapid adoption of sheep and cattle herding brought significant changes to the spatial, economic, social, and political organisation of coastal societies.
Bio:
Dr Maximilian Jan Spies is a postdoctoral research fellow under Professor Judith Sealy in the Department of Archaeology at the University of Cape Town. He has recently been exploring the use of strontium isotopes to help answer questions about how people lived and moved across the landscape in the past. With his background in forensic anthropology, he hopes to expand into other isotope systems for use in forensic contexts.
Link to the YouTube recorded talk: https://youtu.be/snvryqbnFNo