Ancient Cave in Kenya Reveals 78,000 Years of Human Activity

Main excavation area, nether structure overhang. Credit: Jennifer M. Miller / CC BY 4.0

A coastal cave successful Kenya has yielded 1 of eastbound Africa’s astir elaborate records of ancient quality activity, spanning astatine slightest 78,000 years crossed 5 chiseled prehistoric periods.

Researchers astatine Panga ya Saidi, utilizing 3D scanning, radiocarbon dating, and geological analysis, person produced caller findings astir however aboriginal Homo sapiens lived and adapted successful a tropical coastal setting.

The study, led by Jennifer M. Miller of the Max Planck Institute of Geoanthropology successful Jena, Germany, was published successful PLoS One. The cave sits astir 15 kilometers (9.3 miles) from the Kenyan coast, perched connected an escarpment overlooking the coastal plains successful the Dzitsoni Uplands.

Kenya’s past cave rewrites eastbound Africa’s coastal record

First identified successful 1975 but not excavated until 2010, arsenic portion of a task tracing aboriginal Indian Ocean commercialized networks, it has since emerged arsenic a cardinal tract for knowing human evolution successful eastbound Africa. Unlike the better-known inland sites of the region, Panga ya Saidi extends that grounds toward the coast.

The 2020 excavation opened a caller 4-by-1-meter (13-by-3.3-foot) trench on the bluish borderline of earlier digging and recorded implicit 3,000 finds utilizing a robotic full station.

Chamber and partition morphology successful PYS. Credit: Jennifer M. Miller / CC BY 4.0

Researchers identified 19 archaeological layers successful the precocious 3.5 meters (11.5 feet) of sediment, with deposits exceeding 5.5 meters (18 feet) successful full thickness. The sediment perchance extends overmuch deeper, perchance reaching backmost beyond 78,000 years.

One of the notable discoveries was a antecedently undocumented concern signifier dating to astir 2,500 years ago, bridging a spread betwixt the known mid-Holocene and Middle Iron Age periods astatine the site.

3D scanning exposes 19 layers and a mislaid concern era

Upper layers besides contained Tana Tradition ceramics, dating to astir 850 to 1,250 years ago, on with grounds of crops, carnal bones, and marine shells, including oysters from intertidal and mangrove habitats, pointing to a mixed foraging economy. A human burial from the apical of the series adjacent yielded recoverable DNA.

Researchers besides traced a large translation successful the cave level during the terminal Pleistocene, erstwhile intensifying quality occupation, alternatively than extracurricular sediment washing in, became the ascendant unit shaping the cave’s interior.

Composition and operation of correlative deposits from Trench 4. Credit: Jennifer M. Miller / CC BY 4.0

Layer 6, dating to astir 16,500 years ago, showed the highest recorded highest successful quality concern strength astatine the site.

Human presence, not erosion, reshaped the past cave floor

Miller and her colleagues determined that the astir archaeologically productive zones beryllium adjacent the enclosure walls, beneath rocky overhangs that erstwhile provided structure and earthy light.

The unroofed cardinal chambers, portion holding perchance deeper sediment, produced acold less artifacts. Enclosed interior chambers, by contrast, served arsenic ancestral burial sites, with entree inactive regulated by ritual among section communities today.

The cave’s origins hint backmost to rising groundwater heavy underground, earlier determination geological uplift, apt linked to the East African Rift System, which gradually exposed it to the surface. That vulnerability triggered the ceiling illness that continues reshaping its chambers today.