Daniel Rosendahl

Late Holocene Changes in Shellfishing Behaviors From the Gulf of Carpentaria, Northern Australia

ABSTRACT Dramatic changes in shellfishing behaviors occur across northern Australia during the late Holocene, marked most conspicuously by the cessation of large shell mound construction in some areas, and the reorganization of shellfishing behaviors towards more intensive production in the last 1,000 years. Excavations reveal rapid and widespread changes within coastal sites, an increasing diversification in overall subsistence resources, and patterns of increase in site establishment and use. Some of these changes have been argued to be associated with increasing climate variability and a trend towards increasing aridity during the late Holocene, thought to have transformed coastal ecosystems and mollusc availability. However, when these hypotheses are tested at the local level, more nuanced patterns of human-environment interaction emerge, which call into question interpretations based on broad-scale climate records. We suggest that disjunctions in the timing of the cessation of shell mound construction noted between the west and east Gulf of Carpentaria may be related, at least in part, to the timing and intensity of external cultural contacts with Macassan seafarers, associated with reorganization of mobility and production strategies, rather than as yet undemonstrated environmental changes impacting on shellfish availability.

Holocene sea-level change and coastal landscape evolution in the southern Gulf of Carpentaria, Australia:

A revised Holocene sea-level history for the southern Gulf of Carpentaria is presented based on new data from the South Wellesley Archipelago and age recalibration of previous research. Results confirm that rising sea levels during the most recent post-glacial marine transgression breached the Arafura Sill ca. 11,700 cal. yr BP. Sea levels continued to rise to ca. –30 m by 10,000 cal. yr BP, leading to full marine conditions. By 7700 cal. yr BP, sea-level reached present mean sea-level (PMSL) and continued to rise to an elevation of between 1.5 m and 2 m above PMSL. Sea level remained ca. + 1.5 between 7000 and 4000 cal. yr BP, followed by rapid regression to within ± 0.5 m of PMSL by ca. 3500 cal. yr BP. When placed into a wider regional context results from this study show that coastal landscape evolution in the tropical north of Australia was not only dependent on sea-level change but also show a direct correlation with Holocene climate variability. Specifically, the formation and preservation of beach-rock deposits, intertidal successions, beach and chenier ridge systems hold valuable sea-level and Holocene climate proxies that can contribute to the growing research into lower latitude Holocene sea-level and climate histories.

Robust local vegetation records from dense archaeological shell matrixes: a palynological analysis of the Thundiy shell deposit, Bentinck Island, Gulf of Carpentaria, Australia

This study investigates the palynological remains (both fossil pollen and charcoal) recovered from the Thundiy shell midden deposit, Bentinck Island, Gulf of Carpentaria, northern Australia, to provide a vegetation and fire record for this site, which sheds light on human occupation of the southern Wellesley Archipelago over the late Holocene. Results show that the development of a high-density shell deposit by human activities was directly responsible for pollen preservation, possibly through the creation of a moist, anaerobic environment that reduces oxidation of pollen grains. The presence of recoverable pollen from a shell midden deposit from Bentinck Island provides a valuable new proxy to provide greater context for archaeological records, particularly in terms of local vegetation information and potential insight into human land management practices.