Emma St Pierre

Rapid interhemispheric climate links via the Australasian monsoon during the last deglaciation

Recent studies have proposed that millennial-scale reorganization of the ocean-atmosphere circulation drives increased upwelling in the Southern Ocean, leading to rising atmospheric carbon dioxide levels and ice age terminations. Southward migration of the global monsoon is thought to link the hemispheres during deglaciation, but vital evidence from the southern sector of the vast Australasian monsoon system is yet to emerge. Here we present a 230thorium-dated stalagmite oxygen isotope record of millennial-scale changes in Australian-Indonesian monsoon rainfall over the last 31,000 years. The record shows that abrupt southward shifts of the Australian-Indonesian monsoon were synchronous with North Atlantic cold intervals 17,600-11,500 years ago. The most prominent southward shift occurred in lock-step with Heinrich Stadial 1 (17,600-14,600 years ago), and rising atmospheric carbon dioxide. Our findings show that millennial-scale climate change was transmitted rapidly across Australasia and lend support to the idea that the 3,000-year-long Heinrich 1 interval could have been critical in driving the last deglaciation.

Cave Archaeology and Sampling Issues in the Tropics: A Case Study from Lene Hara Cave, a 42,000 Year Old Occupation Site in East Timor, Island Southeast Asia

Abstract New evidence from Lene Hara Cave, East Timor, demonstrates that it was first occupied by modern humans by 42,454±450 cal BP at approximately the same time as nearby Jerimalai shelter. Together these sites constitute the earliest evidence for modern human colonisation of Island Southeast Asia east of the Sunda Shelf. Here we report on the dating and stratigraphy from the 2000 and 2002 test excavations at Lene Hara, as well as new dates obtained by sampling breccia deposits in 2009. The post-2000 excavations and sampling demonstrate that different areas of the cave preserve different sedimentary sequences and necessitate a revision of our earlier interpretations of the occupation history of the cave. At Lene Hara, and other caves with complex depositional histories in tropical regions, the occupation sequence will only be revealed through integrating information from extensive areal sampling. When calibrated, the early dates from East Timor now align closer to the oldest evidence for occupation in northern Australia, with substantial implications for current theories on the colonisation of this region by modern humans. The Nusa Tenggara (Lesser Sunda) island chain emerges as a likely passage for modern human entry into Greater Australia. In view of the short water crossings required to reach Flores from Timor, the apparent absence of modern humans on Flores prior to the Holocene appears highly anomalous.

Faces of the ancestors revealed: Discovery and dating of a Pleistocene-age petroglyph in Lene Hara Cave, East Timor

A petroglyph showing a human face found in East Timor is dated to the late Pleistocene. It recalls ancient Australian forms and raises the possibility of connecting early cave art with the better known painted figures of Lapita/Austronesian art ten millennia later. This new discovery at a known cave shows what precious evidence still lies in store even in well-trodden places.

Cook Island artifact geochemistry demonstrates spatial and temporal extent of pre-European interarchipelago voyaging in East Polynesia

Significance Oceania, the last region settled on Earth, witnessed the greatest maritime migration in human history. Scholars have debated how and when islands were colonized and the role of postsettlement voyaging in maintaining founding colonies and in subsequent diversification of island societies. We geochemically “fingerprinted” exotic stone artifacts from a well-dated archaeological site in the Cook Islands, matching artifacts to their geological sources and demonstrating that the geographical voyaging network extended beyond the Cook Islands to include the Austral, Samoa, and Marquesas archipelagos—up to 2,400 km distant. We further demonstrate that Polynesian interarchipelago voyaging lasted from about AD 1300 to the 1600s, suggesting that long-distance interaction continued to influence the development of social structures in East Polynesia well after initial colonization. The Cook Islands are considered the “gateway” for human colonization of East Polynesia, the final chapter of Oceanic settlement and the last major region occupied on Earth. Indeed, East Polynesia witnessed the culmination of the greatest maritime migration in human history. Perennial debates have critiqued whether Oceanic settlement was purposeful or accidental, the timing and pathways of colonization, and the nature and extent of postcolonization voyaging—essential for small founding groups securing a lifeline between parent and daughter communities. Centering on the well-dated Tangatatau rockshelter, Mangaia, Southern Cook Islands, we charted the temporal duration and geographic spread of exotic stone adze materials—essential woodworking tools found throughout Polynesia— imported for more than 300 y beginning in the early AD 1300s. Using a technique requiring only 200 mg of sample for the geochemical analysis of trace elements and isotopes of fine-grained basalt adzes, we assigned all artifacts to an island or archipelago of origin. Adze material was identified from the chiefly complex on the Austral Islands, from the major adze quarry complex on Tutuila (Samoa), and from the Marquesas Islands more than 2,400 km distant. This interaction is the only dated example of down-the-line exchange in central East Polynesia where intermediate groups transferred commodities attesting to the interconnectedness and complexity of social relations fostered during postsettlement voyaging. For the Cook Islands, this exchange may have lasted into the 1600s, at least a century later than other East Polynesian archipelagos, suggesting that interarchipelago interaction contributed to the later development of social hierarchies.

The Walandawe tradition from Southeast Sulawesi and osseous artifact traditions in island Southeast Asia

This chapter describes a sample of points and other osseous artifacts recovered from Holocene contexts at three sites in Walandawe, Southeast Sulawesi, Indonesia. Microscopic observations of use traces and manufacturing techniques are presented as well as metrical observations and morphological classifications. The points show a suite of temporal trends apparently related to a shift from a predominant use as hafted projectile points to their growing use as penetrative tools. Trends include a higher incidence of wear and decline in tip damage, a decrease in bipoint production, an increased focus on unipoints, and a manufacturing shift from predominantly scraping cortical bone to frequently grinding suid incisors and long-bone shafts. Notwithstanding these changes, the Walandawe osseous artifacts constitute an identifiable tradition with systematic differences from other Island Southeast Asian assemblages located in southwest Sulawesi and especially Borneo, the Aru Islands, the northern Moluccas and the New Guinea Bird’s Head.