Paleoenvironmental context of archaeological sites, implications for subsistence strategies under Holocene climate change, northern Kenya

Abstract

The Holocene was time of dramatic climate change in East Africa, shifting from wetter climate in the Early-Mid Holocene (ϳ10-5 ka) to drier climates in the Late Holocene, followed by a slight reversal at Ͻ1 ka. The Holocene was a time of cultural change from huntergatherer and fishing to pastoralism. Recent excavations along the eastern shores of Lake Turkana, Kenya (4°N) provide new archaeological materials, a high-resolution stratigraphic and paleoenvironmental data set, OSL dates, and cultural records in the context of documented environmental change (falling lake levels). Archaeological site FwJj25 (4.20 Ϯ 0.28 ka), on the northeastern margin of Lake Turkana, provides one of the earliest records of pastoralism in the region. The palimpsest record of FwJj5 (0.90 Ϯ 0.06 ka) was in a small valley containing a groundwater seep located 5 km from the lake. FwJj5 reflects occupation by people who may have covered great distances in accessing resources, but were likely drawn to an environmental refugia of freshwater springs during times of regional aridity.

Lakeside View: Sociocultural Responses to Changing Water Levels of Lake Turkana, Kenya

“…GaJi4 is an early pastoral site with a recently generated radiocarbon age on charcoal of 4,180±40 14 C years BP (4,580-4,840 cal. years BP, Beta-252053, Ashley et al 2011), but is coeval with the final regression of Lake Turkana. Importantly, a charcoal age associated with an eroded human burial and barbed bone points at the "Lothagam Fishing Site" is 6,300±800 14 C years BP (5,320-8,970 cal.…”

Testing and refining the timing of hydrologic evolution during the latest Pleistocene regressive phase of Lake Bonneville

“…Continuous power or continuous wave OSL (CW-OSL) was conducted in all measurements. Similar to other recent studies (Lukas et al, 2007;Morrocco et al, 2007;Spencer and Robinson, 2008;Ashley et al, 2011;Rittase et al, 2014), post-infrared optically stimulated luminescence (post-IR OSL) was used to measure the luminescence from the quartz grains. This procedure removes charge sensitive to infrared stimulation, commonly associated with remnant feldspathic minerals, before measuring OSL from the quartz grains.…”

Paleoindian Open‐Air Sites in Tropical Settings: A Case Study in Formation Processes, Dating Methods, and Paleoenvironmental Models in Central Brazil

“…Although several authors have dealt with the relationship between soils, archaeological materials, and paleoenvironments, most approaches address soils in temperate (Haynes, ; Mandel, ; Cordova et al., ; Holliday et al., ) or Mediterranean climates (Angelucci et al., ; Mallol et al., ) or, when in the tropics, in semi‐arid environments (Ashley et al., ). We therefore argue for the necessity of approaching the archaeological record in humid tropical soils with a geoarchaeological perspective, leading to the development of a tropical geoarchaeology, providing a fresh approach toward long‐held assumptions about tropical soils made by pedologists and geomorphologists.…”