Liang Bua Cave, Indonesia - Archaeological Site of Flores Man

Archaeology of the Flores Man Site

Liang Bua Cave, Flores Island, Indonesia
Liang Bua Cave, Flores Island, Indonesia. Rosino

Liang Bua is the name of the karst limestone cave from which Flores Man (a.k.a. the Hobbit) was found. Liang Bua is located in the Wae Racang Valley on the western end of the tiny island of Flores in Indonesia. Within its deposits have been found both modern humans and the hominin remains somewhat controversially called "Homo floresiensis": it is currently the only known location for the recovery of H. floresiensis.

Liang Bua cave is about 14 kilometers (7 miles) north of Ruteng, the regional capital. It is 20 meters (65 feet) wide, 25 m (82 ft) high at the entrance and 40 m (131 m) deep. The cave was created by karst action 600,000 years ago, but evidence suggests that it was invisible from the surface until it was exposed by the Wae Rancang river about 190,000 years ago.

Human Occupations

The earliest evidence for humans in the cave dates to 190,000 years ago, and it includes a collection of artifacts at the back of the cave. These were washed into the cave by the river, but they indicate the presence of hominins in the area. They are believed to have been artifacts made by Homo erectus, who first appeared on Flores Island beginning 840,000 years ago.

Two later occupations of the cave are associated with Homo floresiensis. The earliest, located near the center of the cave and along the west wall dates between 74 and 61,000 years ago.

The more recent dates between 18,000 and 16,000 and is located by the east wall.

Finally, modern human skeletal remains were recovered from Liang Bua within Holocene levels, within the past 11-12,000 years or so), including six Neolithiic and proto-Metallic age burials with grave goods.. None of the bones recovered from Pleistocene deposits in Liang Bua cave appear to be modern H. sapiens, according to the research team.

Homo sapiens first appeared in the region circa 55,000-35,000 years ago.

Chronological Reassessment

Reanalysis and dating of the stratigraphy at Liang Bua cave have completely revised the chronology of H. floresiensis. A 2016 article by Sutikna et al. describes an unconformity in the site stratigraphy that was not recognized by the excavators that led to a miscalculation of the site's history and makeup.

Uranium/thorium dates on three H. floresiensis bones returned dates ranging between 86,900 to 54,600 years ago; argon dates on volcanic tephras (basically soil created from ashfall) lying above the H. floresiensis levels are consistent with the direct dating. Results of a new dating technique called laser-ablation uranium-series isotope analyses of associated stegodon bones conducted for this paper also support Sutikna et al.'s interpretations.

Out with the Old, In with the New

Charcoal used for previous radiocarbon dating of the hominid is now recognized as were much later than the last appearance. Earlier published luminescence dates of the underlying samples now appear to have been compromised by sampling across the unconformity.

It is unclear from the 2016 paper if this interpretation still supports the presence of multiple habitation zones in Liang Bua cave, and only a handful of the hominin samples (LB1, LB8, LB6 and LB4) are plotted with respect to the new stratigraphy.

Sutikna et al. indicate that all skeletal remains from H. floresiensis date between 100,000 and 60,000 years ago.

Artifact Assemblages at Liang Bua

The artifact assemblages from the H. floresiensis levels include a fairly sophisticated suite of stone tools, particularly within a level dated to ca. 74,000 years ago (+14/-12 ka) that contains stone artifacts with evidence of hard-hammer stone tool production. Raw material for the stone tools was mostly volcanic glass, with some marine limestone. The reconstructed stone tool manufacturing process is similar to sites of the same age found throughout Southeast Asia: a combination of off-site production of large stone blanks and on-site blank reduction. These methods were used by all hominids in southeast Asia around at the time: H. erectus, H. sapiens, and (assuming Flores is a separate species) H. floresiensis.


This article is a part of the guide to the Flores Man.

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