Geo-archaeological and geometrically corrected reconstruction of the 1.84 Ma FLK Zinj paleolandscape at Olduvai Gorge, Tanzania

Palaeogeography, Palaeoclimatology, Palaeoecology

et al. 2017

Self Cite

“…2), which are easily recognizable and can be traced from FLK NN, to the south at PTK and AMK, and even to the east near the KK fault (Uribelarrea et al, 2014) (Fig. 1C).…”

Section: Methodsmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The FLK Zinj paleolandscape: Reconstruction of a 1.84 Ma wooded habitat in the FLK Zinj-AMK-PTK-DS archaeological complex, Middle Bed I (Olduvai Gorge, Tanzania)

Arráiz

Barboni

Palaeogeography, Palaeoclimatology, Palaeoecology

et al. 2017

Self Cite

“…1). Recent excavations (18)(19)(20)(21) Fig. 1D) exposed a traceable thin (5-50 cm), waxy green to olive-brown clay horizon developed by pedogenic alterations of playa lake margin alluvium (22).…”

Section: Significancementioning

confidence: 99%

“…0.05) occurs within 5 km of either forest or standing freshwater (35). Given a paucity of shaded refuge and potable water in the catchment, the concentration of hominin butchery debris (18)(19)(20)(21) exclusively within the forest microhabitat and adjacent to a freshwater wetland (Fig. 4) is notable.…”

mentioning

confidence: 99%

Dietary options and behavior suggested by plant biomarker evidence in an early human habitat

Magill

Proc. Natl. Acad. Sci. U.S.A.

Domı́nguez-Rodrigo

et al. 2016

The availability of plants and freshwater shapes the diets and social behavior of chimpanzees, our closest living relative. However, limited evidence about the spatial relationships shared between ancestral human (hominin) remains, edible resources, refuge, and freshwater leaves the influence of local resources on our species' evolution open to debate. Exceptionally well-preserved organic geochemical fossils-biomarkers-preserved in a soil horizon resolve different plant communities at meter scales across a contiguous 25,000 m 2 archaeological land surface at Olduvai Gorge from about 2 Ma. Biomarkers reveal hominins had access to aquatic plants and protective woods in a patchwork landscape, which included a spring-fed wetland near a woodland that both were surrounded by open grassland. Numerous cut-marked animal bones are located within the wooded area, and within meters of wetland vegetation delineated by biomarkers for ferns and sedges. Taken together, plant biomarkers, clustered bone debris, and hominin remains define a clear spatial pattern that places animal butchery amid the refuge of an isolated forest patch and near freshwater with diverse edible resources.biomarker | leaf wax | carbon isotope | paleoecology | human evolution S patial patterns in archaeological remains provide a glimpse into the lives of our ancestors (1-5). Although many early hominin environments are interpreted as grassy or open woodlands (6-8), fossil bones and plant remains are rarely preserved together in the same settings. As a result, associated landscape reconstructions commonly lack coexisting fossil evidence for hominins and local-scale habitat (microhabitat) that defined the distribution of plant foods, refuge, and water (7). This problem is exacerbated by the discontinuous nature and low time resolution often available across ancient soil (paleosol) horizons, including hominin archaeological localities. One notable exception is welltime-correlated 1.8-million-y-old paleosol horizons exposed at Olduvai Gorge. Associated horizons contain exceptionally preserved plant biomarkers along with many artifacts and fossilized bones. Plant biomarkers, which previously revealed temporal patterns in vegetation and water (8), are well preserved in the paleosol horizon and document plant-type spatial distributions that provide an ecosystem context (9, 10) for resources that likely affected the diets and behavior of hominin inhabitants.Plant biomarkers are delivered by litter to soils and can distinguish plant functional type differences in standing biomass over scales of 1-1,000 m 2 (11). Trees, grasses, and other terrestrial plants produce leaf waxes that include long-chain n-alkanes such as hentriacontane (nC 31 ), whereas aquatic plants and phytoplankton produce midchain homologs (e.g., nC 23 ) (12, 13). The ratio of shorter-versus long-chain n-alkane abundances distinguish relative organic matter inputs from aquatic versus terrestrial plants to sediments (13): Lignin monomers provide evidence for woody and nonwoody plants. This refracto...

Widespread freshwater carbonate in the Olduvai Basin, a precursor to a major eruption in the East African Rift System

The Depositional Record

Wet

Houser

et al. 2020

Freshwater limestones are uncommon in the sedimentary record of the East African Rift System. Recent research in the Olduvai Basin, Tanzania has revealed an extensive carbonate unit ca 1.8 Ma in age that varies spatially in thickness, petrography, trace element and rare earth geochemistry, C and O isotope values and freshwater microfossils. Five distinct lithologies are recognized. Four reflect deposition in carbonate‐rich environments that occurred at the same time in a catena‐like pattern over a heterogeneous landscape: spring, wetland, freshwater lake/pond and saline playa lake. The fifth is carbonate nodular soil that formed by paedogenesis on areas of topographically higher terrane. The δ18O of the carbonate, as negative as −6.5‰, indicates that the groundwater is meteoritic derived. The origin of the carbonate comprising this thick, extensive, isochronostratigraphic deposit has not been determined, but it is believed that carbonatite volcanism may have supplied elevated levels of carbonate to the basin which then entered the groundwater system. The carbonate was deposited just prior to a major trachyte‐phonolite eruption of Mount Olmoti, and the deposition of a basin wide tuff, Tuff IF. The region is seismically active today and seismic events were likely associated with Olmoti volcanism. The widespread carbonate unit may have preceded the Olmoti eruption and formed from a recurring seismically induced increase in aquifer porosity and permeability. The carbonate‐enriched groundwater episodically discharged onto the land surface, interacting locally with both fresh and saline ponded water.